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Bakfiets earns its flames!

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    The regenerative braking on Electra Fat with a Mxus 3000 Turbo is nothing short of amazing. I don't use any pad material. The switches in my brake levers turn on a set amount of regen and it is a little harder than a normal braking situation. The major drawback to regen is it like to loosen axle nuts even though I have two sets of torque arms set for opposite rotation. I just purchased some Nord-Lock washers to see if it will fix the problem.

    I have no experience with geared hub motors but through a friend I have found out that the run of mill eBay DDrive kits are junk. They work but with excessive heat. My friend I have had good luck with the Edge 1500.

    This is a direct drive (DD) hubmotor that I have been waiting for someone to produce the last two years, and now, someone finally has. This article will explain what’s good about it, and why …

    That motor is made for 135mm dropouts with a 7 speed freewheel. I just measured a Shimano 7spd freewheel and it came in a little under 36mm. so if you extended the axle flats on the motor I think you could get it down close to 100mm. If I had a bare motor around I would measure it for you. Cutting the axle is doable with a hacksaw and a good file. If you happen to have a Bridgeport laying around that would work too.

    Qs motors also make motors with only one attaching point for small Quads. If you wanted to rework your whole frame maybe those could be used. Of course to do that you would need a whole second bike. A second bike is the route I would take but not everyone is as sick with this ebike disease as me.


    • tklop
      tklop commented
      Editing a comment
      Thank you for your reply!

      Eventually, I think I'll be interested in one of the carving models of bakfiets--and those beasts use stub-axle wheels... So, if QS makes a motor that'd give me 3WD on one of those--I'd be all for it!

      For now, I'm not interested in frame-modification, simply because the frame I've got is rusting away. The model of bakfiets (my donor-bike) is common here, and readily available 2nd-hand--thus my modular plans. I want to be able to basically just swap parts to a new(er) bakfiets--and be on my way--when the current one finally gets too rusty.

      The cheap Suring brand 350W geared motors I've got, gave me a tremendous power-boost, working side-by-side up there. Granted, they had a fantastic gear-ratio for high-torque, but still... If that's what 350W per-side will give me... Hmmm...

      My thought, was to get a pair of (admittedly cheap) 1000W DD's--and run them "soft" most of the time--reduce the amperage down until I'm peaking out around 500W or so (per motor). I might even wind up asking the motors for more braking power than I ask for in terms of pulling power!

      My hope--feeble as it may be--is that under generally "gentle" use, that maybe even cheap-ass Uncle Ali DD's (perhaps also from Suring) will be alright...

      I've got some messages out there to other vendors too--and we'll see. Maybe there's an off-brand motor out there, with an aluminum stator, thin laminations--all that good stuff. I do so wish I could avoid the risk of over-heating... I'll certainly insist on temp-sensors in whatever motors I buy--in any case!

      It's good to know about the braking-issues--loosening axle-nuts. I will be sure to watch for that too!

      Any further advice, hints, opinions--pour it on me!

      I really do appreciate it!

      Take care, calfee20

      [another edit--insertion]... I've got the e-bike disease... Proof? That DD motor has me thinking of even more madness in future... Maybe for my next bakfiets, instead of the Cyclone--I could go with 3DD's! Quite a stealth-bakfiets that would be! Even if I stick with the cheaper ones up front, I could plop that Edge into the rear-wheel too! [end edit]
      Last edited by tklop; 05-23-2019, 12:55 PM.


    That motor is made for 135mm dropouts [...] so if you extended the axle flats on the motor I think you could get it down close to 100mm. If I had a bare motor around I would measure it for you. Cutting the axle is doable with a hacksaw and a good file. If you happen to have a Bridgeport laying around that would work too.


    I wish I had one of these things to play with. I wonder how the shaft is fit to the stator. Sometimes they're pressed in, but sometimes you can use temp differences to get such things apart (and reassembled).

    Seems to me, just replacing the shaft--would be better than reworking the one that's there.

    If I'm gonna fantasize--why not go overboard? I could imagine milling out and splining the inside of one of those heavy aluminum stators--and putting in a splined steel super-thick motor shaft--one that is machined to precisely and completely fill up your dropouts--forming its own "torque arm" with only the last bit terminating in something small enough to thread an axle-nut onto! Madness, I say! Madness!

    It seems to me, the whole hub-motor idea is wrong. Hub motors are trying to twist against their axles--and that's the weakest point (mechanically speaking). Seems to me, a motor that somehow interacted with the outside edge of the wheel--as opposed to the center--would have one heck of a lot more leverage. I can imagine such a thing--electromagnetic arrays--basically motor-coils mounted to the chain-stays, or seats-stays (perhaps forming a nice arc between the two), and these would act to pull on permanent magnets--attatched to large discs that somehow are bonded to the spokes... Like those aerodynamic racing-discs--only in this case, it'd be part of the drive system... In my whacky cartoon-mind version of this, it'd provide a lot more leverage than trying to twist against a tiny central axle-shaft... But just 'cause it's in my imagination, doesn't mean it's actually possible. I've no idea--I'm just a dreamer, not an engineer!

    One thing's for sure, the technology isn't done developing.

    Though I'm never in the position to afford the newest and latest, I'm always interested to see what's coming next.
    Last edited by tklop; 06-07-2019, 08:26 AM.


      I knew the day would come...

      The bakfiets earned its flames, but now is seeking retirement. It has finally succombed to the forces of corrosion...

      No worries--as from the very beginning, all my mods have been modular--with the intent of shifting everything to a new(er) Babboe Big...

      Due to rust primarily, cracks formed along some welds underneath the box-frame.

      They finally gave way yesterday afternoon (just after I'd done a ton of work on the machine--figures).

      Today I'll be buying its replacement (another non-electric version).

      I expect to have some pictures to post--of the destruction!

      More to follow...

      All the best, everybody!



        It's easy to see that the cracks have been there a while, due to the amount of rust visible along the surfaces of much of the torn steel.

        The new donor trike is here (only a 15km leg-powered ride away), but I've a heck of a lot of work ahead of me.

        I've included a picture of it in its "virgin" --non-electric state.

        i know what I'm going to be busy with for the next little while! (Yeah--it's going to be a lot of work--but I'm not really complaining).

        More to follow, to be certain!
        Last edited by tklop; 08-04-2019, 09:04 AM.


        • calfee20
          calfee20 commented
          Editing a comment

        • tklop
          tklop commented
          Editing a comment
          Saw the cracks, tried to limp it back home--and it gave way literally in sight of my apartment building.

          I did indeed have to haul the two halves of the bike in separately--first the box, then back for the (awkward-as-hell-to-maneuver) rear-frame.

          Only a small leg-gouge though... The bakfiets itself suffered the worst of it!

        I've spent much of the last couple days taking my original bakfiets apart, as well as "sorting out" the electronics, and preparing everything for a smooth install on its replacement.

        Having dissasembled the old bakfiets, I was able to bring the (now smaller) pieces into my apartment, to accomplish these goals (luckily--as I've got no other place to work).

        The electrical components are now mounted onto a single removeable panel, with most items being able to simply plug-in or plug-out of that panel.

        There will be pictures...

        Among improvements will be:


        12VDC Electrical System added (via a buck transformer), including a four-way distribution block with automotive-style blade-fuses.

        Dual LED headlamps.

        Box-side turn-signals with column-mounted automotive-style control switch.

        1 ea 12VDC outlet (cigarette-lighter style, for laptop, portable refrigerator--whatever)

        4 ea USB charging outlets (one or two of which I may choose to use for supplimental lighting).

        Waterproof motorcycle-style Bluetooth stereo

        I will also add an electric moped-style horn--but that's the only piece I don't yet have on-hand.


        I've left room on that panel for eventually installing a sine-wave inverter. I've thought that might be handy too, so I can power regular stuff--off of my bakfiets battery (for camping, etc.)

        Further improvements to the existing systems, include disc-brakes for the front-wheels (new front-wheel hub-motors, same specs--just disc-brake versions this time). The DIY brake-disc adapters are pretty cool--letting you mount disc-brakes to whatever you like--but they're not as stiff as something welded to the frame would be--so I wouldn't consider them ideal. Still, even though the discs may "sing" a little, they don't drag--and the stopping was really smooth and nice--at least during the "last ride" of the "first bakfiets" it was...

        If my brakes "sing" or "moan" sometimes--that's not so bad. A little "early-warning" to other cyclists--for safety's sake--isn't so bad!


        What was already there will be done more nicely than before. I hope it'll be something I can feel a little more proud of--not so cringeworthy as the "prototype" was...

        More to follow--with pictures...

        Last edited by tklop; 08-06-2019, 01:48 PM.


          Much progress on the bakfiets...

          It's all operational, though I need to get a few things sorted out still.

          One more day ought to be enough.

          It is a much improved machine!

          I've yet to do a full test ride, but it is going to be much better than before.

          Pics will follow...

          Still running the Suring brand 350W geared-hub motors up front. They're brand-new motors--but I ordered them with the same spec windings (12T, max torque, low top-speed)--but I decided to try to go with disc brakes this time, instead of the roller-brakes (which were just too finicky and never stopped dragging).

          So, for the front-wheels, I'm using TRP Spyre mechanical (cable-operated) brake-calipers (mounted to adapters), acting on 203mm discs. I can stop on a dime, the parking-brakes work as never before, and there's absolutely no "dragging" anymore.

          The Cyclone mid-motor has itself a new set of chainwheels, and a nice alloy chainguard (as always, my thanks to, Paco--at Cyclone-TW).

          I noticed however, there were barely 1 1/2 threads engaged on the hollow thru-bolts that hold all the chainrings together. I guess adding in the alloy chain-guard made it all just a little-bit too much thickness for single bolts to work with.

          Maybe it varies with chain-ring selection, but in my own case, all three chain-rings, as well as the alloy chain-guard are sharing the same 4 hollow chainwheel-bolts.

          The ones Cyclone used, are the longest available (at least that I could find), but they're obviously not really long enough to be effective with the alloy chain-guard.

          I took apart and re-assembled the unit with one fewer washers between the inner-two chain-rings. Hopefully that'll give it enough extra thread-engagement to be okay. This appears to be fairly solid--but only time will tell. The motor-driven chainwheel's holes are made for the threaded-portion to go through, with the nut on the drive chain-rings' side. With the addition of the alloy chain-guard, this meant more "slop" under the threaded portion of the bolt--where it's trying to hold the chain-guard in place. To eliminate this, and increase stability, I swapped out the washers between chain-guard and motor-driven chain-ring, to match the narrower diameter of the bolt's threaded-portion. There was also a slight 'tick" as the tops of those same bolt-heads touched the crank-arm as it rotated on the freewheel. I simply worked patiently with a nice metal-file, to reduce the material on the inboard-side of the crank-arm, until there was enough clearance.

          Both these issues weren't a "thing" with the original plastic chain-guard. That thing wasn't either very pretty nor sturdy--but because it also didn't share the same mounting-holes, these things just weren't an issue...

          Anyways... We're do-it-yourself-ers. We adapt, and we overcome!

          I love the way it all looks...

          Lots of black, lots of wood--no hideous hand-painted flames, not weathered ugly swollen wood panels...

          I've now got 4 USB outlets, in two pairs--one on the handlebars, and one inside the box. They'll both supply up to 5A max (per pair of 2)--so now my "cellphone dashboard" doesn't need a separate powerbank.

          Plus, I've discovered I'm able to utilyze that same 5VDC source to power my taillights. Yes, I'm sticking with bicycle-components for the tail-lights. One main reason for this, is that I can get top-notch maintenance-free products that are made for exactly what I'm using them for.

          Obviously, the LED bike-lights are meant to run off a dynamo, or off an e-bike's "lighting" circuit. However, I've discovered they also work perfectly fine on the 5VDC signal from a USB charger (or powerbank).

          This discovery simplified the heck out of things.

          A couple upgrades to B & M Secula fender-mounts, and I'm glowing like a damn airplane!

          E-bike headlights--unlike the taillights--consume a lot more energy. I'm not sure whether the USB-voltage circuit might have been able to keep up.

          In any case...

          The lights I've got now? Heh, heh... Plenty bright! One of them would've been more than double what I'd "need" ---and I've got two!

          Unlike those really nice B & M e-bike headlights, there's a ton of glare off these. Broad enough beam for good in-fill at close-range, but the illumination is also quite far-reaching. I've done my best to make sure they're not aimed too high. Still, I would reccomend the model (for anyone considering 12V bike-lighting).

          Outwardly, the machine is so much less ugly than the last bakfiets... It's a really nice feeling to be able to walk up to it, and not feel the need to apologize for its hideousness...

          I'm not sure whether or not to go with the "bumper" again... It makes people frown at me--but it also makes them give me a wider berth... Plus, it'd do wonders to protect the lights I just installed... I just hesitate as well to drill a bunch more holes into these still-very-nice wooden panels...


          More to follow... As always!

          I'm going to post some more photos.
          I got it fully operational, and did some test-drives.

          I've got issues with the Cyclone's power-cable that'll need to get sorted out.

          The front-wheel hub motors seem a bit louder than the previous set were.

          The high-gear-ratio motors are unbelievably strong--and let out an awesome banshee-like wail when under heavy power (the terrifying sound made more supernatural of course because there's two of them--unsychronized and wavering in tone).

          If I mash the throttle, running only the two front-wheels, I'm peaking out at approx. 40A. At 48V that's pretty much 2000W coming from the BMS.

          I know there's some loss in the controllers, and that the motors are probably losing some to efficiency... But...

          That still comes out to about 1000W drain--per front-motor--and that still seems like quite a lot of extra wattage, compated to the motors' 350W rating.

          I'm convinced they're consuming a hell of a lot more than 350W--and the evidence is in all that blistering acceleration I've got available...

          I may wish to "tame" the front-systems, similarly to what I've done with the 4KW Cyclone.

          I will want that "full-power" depending upon my usage, or situation. If I want to go down the beach, I need a ton of power. But for asphalt, not so much.

          To give myself the versatility I want, I may hook the KT-LCD3 displays up to them. They run without the displays (I ordered the special "jumper" to allow this). But either way, I'll let the displays remain inside the electronics bay--they're not going to live on my handlebars. Those displays actually allow quite a lot of controller customization--quite configurable.

          I may still want "Banshee-Mode" for when I'm about to overtake somebody. Like a motorcycle, I can hum quietly along, but then if when I "punch it" --it can "wail" on demand--that's a similar feature to a motorcycle's exhaust-noise--in terms of the desired effect of alerting other cyclists--but unnerving as my machine's wail may be, it'll needlessly awaken fewer napping babies than "loud pipes" do.

          Not all is as it should be though... Not just yet.

          The Cyclone's power-cable is giving me problems.

          I've got the waterproof cable, but have had to make repairs to it. I may try one last time to make the current cable work, but if it doesn't, I'll have to just take the time and replace the whole thing.

          It's possible, and I've already got what I need. I've got two-meter lengths of #10 silicone cable, in blue, yellow, and green--which will be more than adequate for the phase-wires; and some 5-strand com-cable which will of course easily carry the hall-signals. I may just have to rewire it motor-to-controller... But I do still feel like want a connector. One of the 3-way MT-60 series--designed specifically for motors' phase-wires--would be great, but they're made for 12 AWG--and there's no such thing as an MT-90 (alas).

          I don't know. Maybe as funky and bulky as it may be I might use a trailer-adapter (weatherproof being a big plus-point).

          But before I decide, I'm going to take a trip to the local RC hobby-shop to see what they've got (if anything).

          Meanwhile, I took some more pics yesterday (with my moble), so I'll try to upload them.


          I've experimented with the control-switch for the KT-LCD3 displays.

          When wired in paralell, one control-switch will provide input to two KT-LCD3 displays.

          Obvioiusly this is handy, if one has dual (or more) systems, which are powered by these units.

          One control-switch, two systems... Power on/off, "walking-assist"--as well as control over the pedal-assist level are all things I couldn't previously do underway.

          Today hopefully will see some test-running, with the front-motors' displays in use.

          It's fun having "insane screaming scary fast"--but I think I'd also like to find some tamer settings. Perhaps learn a few "quick configs" so I can alter settings depending on what I'm up to (on or off-road, loaded/unloaded, --or just feeling like a speed-demon).

          I got errors trying to upload more pictures, but will try again today.

          The disc-brakes are awesome for stopping, but are horribly loud. Obviously, the after-market brackets aren't stiff enough to dampen vibrations.

          If I really "mash" on them, they're quiet, but anything less, and they sound like a semi-truck. It's an early-warning "get out of my way or die" kind-of sound, so there's a certain benefit to that. But it's not very nice. I'm not sure what (if anything) I can do about it--short of figuring out how to braze on better caliper mounts (not likely).

          More to follow....
          Attached Files
          Last edited by tklop; 08-12-2019, 03:22 AM.


            I am slowly making progress uploading photos to the previous post.

            Every time I do, it gets flagged for some reason. Anyway--if it's one or two photos per day, I'll eventually get some more ^ up there! ^ :-)

            Whenever approved, the latest shows the handlebars (as currently configured).

            Yeah--twin displays is silly--when I ultimately prefer none--but it's going to really help with configuration.

            Once I've got the settings where I want them, I can remove the displays--or store them in the electronics bay--leaving only the control-switch on the bars.

            What I have noticed (while testing parked) is that if I tick through the PAS settings quickly, sometimes one of the displays won't register the click. In this way, it is possible the the two displays can get out of synch (one PAS level higher than the other) resulting in an asymmetrical pull.

            Though the displays will indicate when this happens--so will the assymetrical pull (which at most will likely be one or two PAS values).

            Obviously letting off the throttle and/or stopping pedaling, or also engaging the brakes would stabilize the asymmetry immediately.

            But then--I was thinking...

            If I was attempting to reach PAS 5 (max), then I could just keep clicking "up" until whichever display was lagging behind was maxed-out too...

            If I was trying to reach any other PAS setting, I'd be better off just clicking "down" until both systems reached PAS 0 (no assist), then ticking back up to my desired level.

            That's all it'll take in either instance re-synch--PAS all the way down, or all the way up. Done. Clearly, I won't really need the display for that either.

            But for now, so long as I'm going to be dinking around with the settings, I may as well leave the displays where I can check them.

            When I'm done with my fine-tuning, I think I might actually set 'em up for "Quick Disconnect"--put a mounting-bar inside the electronics bay... I've already got almost all the parts to make it doable!

            There's lightning striking outside. I'm kinda glad I'm not out on a bakfiets adventure--but hey--I can always shelter (temporarily) in the tent. Got tunes, got my USB power so the phone won't go dead...

            More to follow--and hopefully more pics soon-- up ^ there ^

            Another thing I want to do, is to consolidate all the sensor circuits...

            What I mean is this:

            I've got three separate BLDC controllers in that bay.

            Each BLDC controller has its own (+) leg (red wire) going to each of its various sensors. All the red wires are common--at least for each controller.

            Each BLDC controller also has its own (-) leg (black wire) going to each of its various sensors. Just as with the red ones, all the black wires are common--but not only for each controller, but for all three.

            The PAS sensor has only one "signal" leg.

            Throttles have only one "signal" leg.

            Speed-sensors have only one "signal" leg.

            Each of these sensors already shares common reds and blacks...

            What I want to do, is to set things up for tidier distribution.

            When my various sensor-wires enter the electronics bay, I want their reds and blacks to all meet up at terminals--distribution points.

            All three controllers could send a single black wire to the (-) distribution-point.

            In order to ensure there's always a red (+) even if one of the systems is shut down, I will run the Cyclone's red-wire, and one of the front-system's red-wires through an on-off-on switch, and then on to the (+) terminals--distribution points. If both systems are operational, either "on" position should work fine. If either system is shut down, the switch will allow me to select the red (+) wire from the remaining active system.

            Low-brake circuits could consolidate too--both brake handles to the same two terminals, along with one "low-brake" sensor from each controller--eliminating another six wires...

            I've already got signal-wires split, going in paralell to both front-systems controllers.

            Both the PAS and throttle--are wired in this way (one controller gets a connection to all three wires--red, black, and signal--while the other controller only gets the signal-leg).

            I've plans to play with paralelling my throttle-signals too, so when turning too far to reach the "handy" throttle, I could maintain speed with the opposite hand... I'm intrigued as well to see what it takes to get the systems to both behave in a reasonably coordinated way--off of a single throttle input.. Precisely the sort of experimentation that such a sensor-distribution-system could facilitate...

            Anyways, I think at the very least, if I could in this way eliminate a big chunk of the extra black and red wires sticking out of my controllers, my electronics bay would be tidier.

            I'll have just as many wires headed in--but I won't need to send nearly as many to my controllers (is my eventual hope).

            I still dream of getting all the handlebar wiring consolidated into a single bundle, which can terminate in a nice aircraft-quality cannon-plug--for ease of assembly.

            But short of that, there's still a lot I can do.

            If I get this all super-simple--super clean; if I can get it looking tidy like a "wiring harness" set up; it'd be sweet.

            Oh--another weird thing I discovered--which I never would've know if it weren't for playing around with the displays:

            The lighting-circuit on my front-motors' controllers--is system voltage. I've already got my happy 12V headlights... I wonder what I could use that circuit for? I didn't care one bit--until I knew I had it--of course... But now--I'm wondering if maybe I do want those B & M e-bike lights! :-)


            Added a picture...

            Not installed, but yeah--that's the idea.

            Switch is to choose the (+) leg if one system is down or switched off (as described earlier).

            This will eliminate at least little bit of the snarl, plus it'll make component swapping simple. I may also make a set or two of jumpers with the standard Chinese connectors--make it "plug and play" for component swapping... Maybe even more than one set of Chinese-connector pigtails--since different brands use different + / - / Signal sequences on their connectors (the ones for my front-motors, and the ones from Cyclone--in any case--are different--and I could make a set of pigtail-jumpers for both brands of components).

            The material for this mini-panel itself was a sample of stairway-refinishing material from the hardware store (glue/sawdust composite basically akin to laminate flooring).

            The "terminal studs" are flush-head machine screws, poking through upwards from underneath. The bottom-side of the panel is countersunk, to allow their heads to lie flush--leaving the bottom-side of the panel smooth. Once those still-raised wood-screws secure it to a blank bit of real-estate on my wooden electrical panel, (with the flush-heads sandwiched between)--then Wha-Lah! --I've got terminal studs (that aren't really)--but good as anything prefab; fully insulated, and easy to stack terminals on (ring or fork). I had to pick a longer screw for the (-) stud, since it has the most terminals stacked on it.

            Modular, modular, modular. This one tiny little thing will let me swap any component--even controllers--without having to disconnect anything else. Plus, it'll allow very easy experimentation with ideas like twin-throttles.

            I only wish I hadn't spent so much time trying to find something more "prefab" --more "finished" --before opting for the DIY solution.
            Attached Files
            Last edited by tklop; 08-16-2019, 10:41 AM.


              I still am on a quest for a decent soldering-iron... Thing is, I'm going to need more than one. I need to solder #6 high-temp super-flex silicone high-strand-count cables--but I also need to be able to solder little dinky stuff.

              And--alas--the beautiful one recommended ain't wired for EU voltage. Sucks to be me sometimes.

              I wonder--if I bring all my own stuff, all prepped to length--if a local hobby-shop might solder the heavy wires for me... For a handshake (with a ten-dollar bill in it) maybe...


                I bet a hobby shop would do so, sure.

                It appears there is a Makerspace to service your area (Zeist), too, per this listing. Free participation, and certainly equipped for soldering, probably large gauge, based upon their projects. That would be a fun place to visit and frequent, if close enough to you. Many such spaces will train you on their equipment; maybe you can bring them Eierkoek and your parts, and learn on their tools.

                Here's a link .

                Fabrication is fun! Build something today. Show someone. Let them help. Inspire and share. Spread the desire.


                • tklop
                  tklop commented
                  Editing a comment
                  Thanks a million for that link! I'd never heard of that--and gosh... It sounds exactly perfect!

                  You're a lifesafer, JPLabs! :-)

                • JPLabs
                  JPLabs commented
                  Editing a comment
                  Great! I'm glad it's new info for you. I was aware of the global database, and since you had posted your location, it was an easy favor, and fun to find a use for that information. I hope it's a useful connection for you. Please let us know if you make it over there.

                Today I rode around, testing various PAS settings for the front-motors.

                It might sound like blasphemy (since we all tend to love lots of power) but I've found that it works best on low PAS settings.

                The motors are much quieter, and their inputs less severe at PAS 1 and 2.

                For just cruising down the asphalt, that "caster-effect" of them pulling together, and the extra stability--are perfectly effective at PAS 1 and 2.

                I chose to set the throttle to be dependent upon the PAS setting, just to see how that works. The throttle remains active, and doesn't seem much diminished. If I want to--I can still get my banshee-screaming acceleration on demand. And either way, the top 3 PAS settings are just a few up-arrow-clicks away--so yeah... Versatility is good--options are good. Tameness is also good, when it comes to efficient operation (and safety too--in fairness).

                The front-motors' top speed is still about 35 kilometers per hour (according to GPS measurement).

                Either system--front or rear--operating at full-throttle (when the rear-frame is in 2nd gear), just begins to "unload" the other--at top-speed. This offers good stability at top-speed, but also reduces the stresses to the drive components (especially on the rear). Full-speed might only be about 35 kilometers per hour--but that's a lot of wind I'm pushing. It takes about 20A to 25A continuous draw to maintain that speed.

                If I decided I really didn't want to waste energy pushing wind, I would be best off keeping my plywood-crate-on-wheels at or below 25 kilometers per hour. Wind-resistance begins to be a factor above that speed--and my range already begins to take a hit at about 30 kilometers per hour. 35 kilometers per hour further diminishes my range, but even then, my range remains above that "two-hours at max-assist" standard.

                Now--"max-assist" maybe technically isn't accurate. I can indeed reach much higher speeds. The front-motors won't really be involved anymore--it'll be all up to the Cyclone. That's not an issue for the Cyclone; even in my 48V system the 4KW Cyclone can still produce four horsepower (at the risk of breaking things). But the amperage-consumption just skyrockets. It is nice to know that I've got such speed available--but I don't anticipate the need to escape any lahars here in The Netherlands. So, I don't consider these "emergency mode" type settings for my range-standard. Plus, as I've mentioned before, the machines ceases to be any fun to drive above about 35 kilometers per hour--it just becomes too intense of an experience (riding on adrenaline and reflexes is mentally exhausting). So, I consider 35 kilometers per hour as my top-speed--even if technically it isn't.

                That said, I still want more battery! :-)

                The Cyclone is more energy-efficient than the front-motors are, and that shows in the amperage-readouts on the BMS.

                "Top Speed" with front-motors only, is between 22A and 25A; with the Cyclone 4KW only, it's between 19A and 23A; with both systems working together (at the resultant slightly-higher top-speed), the reading is between 22A and 24A. So clearly, three-wheel drive is less efficient than rear-wheel drive. But in spite of a slight hit to my range, I feel the stability, and the reduced drivetrain wear still make it worthwhile.

                More to follow--surely!
                Last edited by tklop; 08-13-2019, 08:37 PM.


                  Here's a neat tip for soldering without an iron. I've used a torch to assist soldering before, but never with this extra end for heat transfer. So simple, and obvious, but hadn't occurred to me.

                  I'd still try the hackerspace, but this could work in the field for emergency repairs. Or for a bike build, frankly. With a normal small iron, a little more heat into the wire is a big help, and makes 10 gage feasible.

                  Fabrication is fun! Build something today. Show someone. Let them help. Inspire and share. Spread the desire.


                  • tklop
                    tklop commented
                    Editing a comment
                    I have ordered a heavier-duty soldering iron (240V 100W), but I'm still not sure it's going to be up to doing 6AWG super-flex.

                    Yet between this--and knowing that you've supplemented with fire--maybe I can find a way to make it work.

                    Had me wondering if a magnifying-glass, and sunlight could give the desired temperatures--or perhaps enough of a "boost" to make it work...

                    Reason I thought of the sun was first--I've got a big magnifying glass next to me--but second, because of what the guy'd said about the oxidation-factor of the flame (the reason for the extension-bit).

                    Sunlight wouldn't do that--unless WAY too hot--right?

                    Anyways--maybe that's just a nutty idea, but I think I may just get some good dark sunglasses, and see if I can give Sun Soldering a shot here--next sunny day I get.

                    I've not yet tried to get in touch with the Makerspace folks--but that's going to happen at some point.

                    Thanks for all your generous tips!
                    Last edited by tklop; 08-16-2019, 10:55 AM.

                  • JPLabs
                    JPLabs commented
                    Editing a comment
                    Whatever you try, use extra paste flux on the joint and it will help fight oxidation. The small amount inside flux core solder isn't enough for big joints, more helps.

                    I bet the sun WOULD work! For the supplemtal heat, if not alone. Nice thinking!!

                  • tklop
                    tklop commented
                    Editing a comment
                    If the sun turns out to be effective, a quality magnifying glass becomes one heck of a handy tool for the toolkit!

                    I'm thinking it might actually be reasonably doable--with some manner to hold the work in place, one hand to guide the focal-point of the concentrated sunbeam, the other to feed solder...

                    Just because it works in my head, doesn't mean it'll work in real-life--but I'm thinking maybe the temps generated might be serious enough to at least "boost" an otherwise inadequate iron...

                    I got a jar of paste flux...

                    I may first experiment with some dinky stuff--and sun-power alone, just to see what I'm working with. We all know it'll get hot enough to burn paper--but I bet it'll get a lot hotter than that. It's nightime right now though--for me! And I'm not sure... Maybe the forecast calls for rain--but who knows? Eventually--we'll see what happens--or doesn't!

                  Did some shopping in the rain today. Picked up four big bags of cat-litter, the biggest cat-box I could find, and a pair of knee-high green rubber boots. Heavy load. Cat-litter was at least a hundred pounds. Took the sandy/muddy horse-path through the forest, to see how the front-wheels do on soft-ground with the softer PAS settings--when heavily loaded. Absolutely unstoppable--just as before--uphill, downhill, through the muck--I even shoved a fallen branch off to the side with the machine--just unbelievable. Basically just rolling along at a quick walk/slow jog pace (faster is of course totally possible, but the path is far too rough--due to all the horse-hooves--after all, I have no suspension).

                  As I am sure you can imagine, the machine was quite messy, when I got back home. I decided to drop off the cat-litter, then go back out into the rain for some rinsing-action.

                  Actually wasn't all that effective at first--trying to rinse the bike by riding it.

                  Eventually, I made it to an old closed airfield, and rode up and down the runway a half-dozen or so times. This worked better for rinsing, as there was more standing water.

                  In some places, there were quite deep puddles.

                  I plunged directly throught them--at 35 kilometers per hour--and that certainly helped with the rinsing!

                  Part of my purchases (as I said) were a pair of knee-high rubber boots. The front-wheels form v-wakes, which converge at the driver's feet. Rain-pants and rubber-boots should be standard issue... Yet only today--a few years into my Bakfietsing adventures--did I finally go spend the fifteen bucks on a pair! They're exactly perfect.

                  I swear--it was way too much fun for anybody to be having in a downpour... And I'd do it again! :D

                  The spray coming off the front-wheels was awesome... I wish to heck I could've filmed the fun.

                  If I think of all the "crazy" ideas I had to start with--many of them have already been acheived. When I got started with all this--back when I first got the Cyclone--the All-Wheel-Drive concept was one of those crazy ideas...

                  Though there's room for advancements. Three-wheel coordination for traction-control (for example) would be great--but figuring that out is beyond my capability.

                  Next up:

                  More weatherproofing:

                  Windshield... Hopefully something that I can consider adapting into a bit of a roof-system (for the rider).

                  Front-fenders... I want something like for a trailer--molded plastic, with a solid inboard-panel--so the box can stay cleaner. Being limited to 105mm width doesn't help a heck of a lot--but I don't want my fenders sticking out past the sides (beast is wide enough). I'm a bit stumped. Internet searches yield nothing but "too wide" items. I am willing to try to adapt an existing product, but I doubt I can split and make narrower--a molded-plastic trailer-fender--or... More precisely--I doubt I could accomplish such a thing without it looking horrible.

                  Box weatherproofing... Maybe some kind of rain-deflection system for the front... I don't mind riding in the rain, but I do need to try to keep rain from getting into the bakfiets. The wooden panels don't like being endlessly soggy; and the Chinese steel is treated internally (so says the manufacturer)--but still is very rust-prone. It's not a boat, but I do need to be vigilant with waterproofing... It's not a boat... But yeah--wouldn't an amphibious version be amazing!?!

                  More realistic than trying to make it float--is to try to develop more accessories...

                  I'm thinking a trailer--with DD-hub-motors set-up for regen--and e-braking--but not ever powered. Trailer-brakes are typically quite twitchy--and the steadiness of the regenerative braking seems like it might actually work quite well. Seems to me, this might be a good way to do "power recovery" --which would be especially helpful when towing... "Drag-braking" also is hell on bicycle brakes--but would be no problem for such a setup... Crazy? Yeah... So was an all-wheel-drive Babboe Big!


                  It was a fun day...

                  Though I've still details to solve, I think the concept can be considered at this point a success. If I can have a blast driving it in the pouring rain--it's good.
                  Last edited by tklop; 08-17-2019, 11:07 AM.


                    Running with both displays on the front-motors has also helped clarify the whole "amperage used verus wattage-rating of the motors" mystery...

                    The motors I bought, are Suring brand (from Uncle Ali) 48V 350W 12T wound (max torque, lowest top-speed), high-gear ratio geared-hub motors--carrying an advertised 75% efficency-rating.

                    The mystery arose, because my battery's BMS indicated that when under max-demand, the front-motors were drawing roughly 1000W per system.

                    I suspected my front-motors were actually much more powerful than advertised because of these readings, and also because of the dramatic amount of power they seemed to give me.

                    Now, my suspicions have confirmation. The front-motors' own KT-LCD3 displays show that each geared-hub motor peaks-out at around 750W.

                    With that advertised efficiency-rating of 75%--that'd mean 1000W peak-consumption; per front-motor system--just as my BMS readout was indicating.

                    So--yeah. Confirmed. My front-motors may be rated for 350W--but with stock controllers, they're peaking at 750W.

                    That means that under my box, I've got (up to) 1500W peak-power, with unbelievable torque. Those high-gear-ratio high-torque motors do wonders for accelleration, and for slow-speeds. Even at low speeds, they cannot be 'bogged down'--and they can start from a standstill, on an incline. The machine + rider + cat-litter was an easy 250+KG; and the "walk-assist" took us all--from a standstill--up the inclined ramp to the entrance to my building--without any issues. When unloaded, and teamed-up with the Cyclone, it's now pretty obvious where I can get that "hang on to the handlebars" acelleration from.

                    Though I have everything very dramatically de-tuned, the "peak" (off-road use only) settings could deliver (up to) 1500W under the box, and another (up to) 2800 from the mid-motor on the rear-frame.

                    Insane--perhaps--but yeah.

                    Ultimate test, will be just what it can and can't do in the dry sands--at the beach. The sand here in The Netherlands is the loosest sand I've ever experienced. It's as if there's just less overal density to it--I can't really explain it. But even the damp sand--you'll sink right into it... It doesn't "pack"--no matter what. Very strange.

                    Damp sand is supposed to be relatively hard. Hell--you can normally drive your 2wd car on it--bike on it--run on it--whatever. No prob.

                    Well, not here. Here, you better be in pretty damn good shape if you're gonna run on the beach--even in the wet sand. It's all very, very soft.

                    I've never seen sand this soft and loose. It is not at all like California or Oregon and Washington; not at all like the Gulf Coast; not at all like any river or lakeshore I've ever seen.

                    Last time I was at the beach here, my 50A nominal 80A peak BMS shut down--just trying to keep me moving on the wet sand--where normally I could've easily been able to push the bakfiets as I walked alongside--had it been the hard wet sands of some Oregon beach.

                    But now way--not here. Just to give you some idea--if you were to stomp your foot, it wouldn't just leave a sharp 1/8" to maybe 1/4" deep footprint--your shoe would go right down into the sand, probably right up to the ankle... In sand--which looks to my American eyes--as if it ought to be firm enough to drive on!

                    It is very strange indeed...

                    I do know that the sands at the beaches here were all dredged. Maybe that's got something to do with the sand's seeming lack of density--I'm not really sure.

                    Look: I know the Dutch are the undisputed heavyweight champions of such things--they've "mastered" the technology of keeping the seas out; I suppose it's pretty hard to argue that point... But the sand's lack of density (to my "outsider's eyes" anyway) has me wondering about those dunes' resistance to the "thousand-year-storms" they were built up to protect against... And will sea-level rise increase the effects of erosion on all that loose sand? These are questions far above my pay-grade; but in a world where politicians deny science, and profit is paramount to all other concerns--I have to sometimes wonder...

                    But yeah... In any case...

                    Point is, it makes for one hell of a serious testing-ground! The wet sand is way softer than you'd expect--and the dry sand--well, it is almost impossible to even walk through!

                    Crying kids--exhausted... Parents also exhausted; and cannot carry them... This is a sad, but relatively common scene at the beaches here, as families try to make it back to their cars, to go home...

                    So, if my bakfiets can climb the soft dry sandy exit-ramps, it'll be the most incredible machine ever--and that'll most definitely have to go on YouTube (closed-course, pedestrian-free, pre-arranged, local Police, Coast-Guard, and Shore Patrol all notified, permits obtained from Parliament, etc.).

                    Yet beyond "for demonstration purposes only" beach-runs, or the like, I doubt I'll ever have need to push the system that hard.

                    Besides--I doubt those motors could sustain that 750W peak-output for very long without overheating. Yet is fantastic to have dramatic capabilities; even if rarely if ever really "maxed out". What the extra capability really amounts to, is a minimally-stressed system when under normal soft settings. Unlike an underpowered system being "pushed to the max" to cruise at 25 kilometers per hour, mine will be relaxed--purring--and will last comparatively much longer (hopefully) as a result.

                    Heck--I don't actually need to use the front-motors at all if I'm going slowly--along with the rest of the bike-traffic--when the surface is decent. In those instances, the Cyclone's higher efficiency-rating gives me more range--and all the power I need.

                    I'd still love to try a set of Luna's 12T Mac Motors with ASI controllers--as the "ultimate" version of my adaptations...

                    Or find a way to squeeze the 135mm Q-motors into my 100mm fixed-steel-dropouts!

                    Some further advancements may be possible yet--even if something like traction-control is well beyond my grasp.

                    When I get my Sensor Distribution Panel in-place, I will be able to have more configuration options on the handlebars--allowing me to "mix-and match" combinations between the two systems, of throttle and PAS inputs, etc. That'll be fun to play around with... Let's face it--it'll never be really "done"!
                    Last edited by tklop; 08-19-2019, 05:54 AM.


                    • calfee20
                      calfee20 commented
                      Editing a comment
                      Your photo sizes are to big. You should keep them under 500K. I adjust the resolution to 1/2 1080p or 1920 X1080 pixels. Infraview is free and does a nice job

                    • tklop
                      tklop commented
                      Editing a comment
                      Thanks, calfee20 I will try to do better in the future. I am not too good at editing--but on your recommendation, maybe I'll check out Infraview.

                      Used to be a way you could select a photo, right-click on it, and select "resize for email" --allowing an easy way to get it done, and re-save the image (or images) even if you didn't want to send it via email... I miss that.

                      Microsloth is hell-bent on driving its customers away as rapidly as possible. To this end, it seems every Windows update strips more capability from their customers' machines. So--unless buried twenty-seven clicks away someplace, that feature is long gone.

                      Now--don't get me wrong--I am not expecting an e-bike forum to include automatic photo-resizing in their website's features--obviously that would be totally unrealistic!

                      I know that no matter what, it's my responsibility to keep my thread tidy. It's my job to be smarter than the problem, and put in the needed effort to make my photos smaller.

                      I'm not sure how to fix the ones already uploaded.

                      Maybe I should delete them all and start over.
                      Last edited by tklop; 08-20-2019, 02:52 AM. Reason: for clarity

                    • calfee20
                      calfee20 commented
                      Editing a comment
                      If you do decide to use infraview I could write up a tutorial for the forum. It has so many capabilities I don't use. I just resize and save photos. it is around 8 clicks for a photo.

                    I've got the cabling tidied up for the lights, and I've got the horn mounted and working too.

                    The horn is plenty loud, but it's a fairly "friendly" higher-pitched tone. It's not unlike an old VW Beetle's horn; a classic Meep! Meep! At only a 3A draw, I figured it'd be okay to power it directly from the switch--without a relay (though of course it's got a fuse too). But any advice to the contrary--will be taken seriously.

                    I could have saved wire, if I used a frame-type electical "ground"--but I've opted not to do that.

                    Still, in certain places, I've been able to imitate the principle, by "sharing" the ground-leg of a circuit--like for the LED lighting.

                    So, I've been able to make everything a lot tidier, but now I've got to return to the nightmare of the electronics bay.

                    Now that it's all pretty much hooked-together and working, I've got to take it apart again, and then start organizing things; routing and bundling wires, installing the 200A Battery-switch, installing some more contol switches--and adding under-bench lights--so that when I lift open the benches, I can see what is inside (to work like trunk-lights--basically--one for the storage-box in the front--one for the electronics bay in the back).

                    The front-motors' drive cables are just plain too long--but I'm reluctant to hack and re-splice them. So a certain amount of "extra length" is just going to have to be coiled and bundled. But other things (hopefully most other things) can certainly be clipped off and neatly routed--for a nicer electronics bay.

                    It's this sort of "refinement" that'll keep me busy.

                    Figuring out how (if possible at all) to make the front-brakes less noisy is another... Refinements...

                    My pile of busted componets yielded a good length of 5-conductor wire--which will be perfect to serve as the "umbilical" between each controller and the sensors' panel. I think I read once (heaven knows where) that mixing "reds" (positive-legs) might cause issues--so I suppose for one of the front-motors, I only really need a four-wire conductor. Busted USB cable--hell, I got lots of those! But the 5-conductor wire; one red, one black--three more for the three required "signal" legs--one for Brake, one for Throttle, and one for PAS. That'll be a refinement to eliminate lots of redundant wires and snarl (that is only really an issue because I've got three controllers). But stuff like that--little by little--will help continue to improve the machine.

                    I want better front fenders. The sides of the frame extend to 130 cm from the sides of the box... If I wanted to keep the fenders "inside" the frame (like the current ones are), I'd be limited to about 4.25" / 105mm. If I go to the limits of the vehicle's width, that'll let me use a 130 mm wide fender (as-in round-shaped, steel, designed for 8" trailer-wheels). The ones I've been seeing everywhere have an inside-radius of 26"--and that's plenty, I think. In any case, that'll let my tires have a lot more breathing-room. Though I'm happy with my Super Moto-X tires, getting the smaller inside-the-frame fenders out of the way will also allow me the potential option to mount much wider tires as well (for those "demonstration purposes only" beach-runs, a bigger footprint would make a tremendous difference). The drop-outs are fixed, and steel--and cannot be increased. But if I could pair up the right rims to my hub-motors, I could use up to a 4" wide tire on each side of the box (any less than 1/4" left-over frame-clearance would be pushing it, I figure). That'd amount to eight-inches of tire-width in front--and with soft-pressures, and some squish--potentially a wee-bit more. In any case--talk about footprint! I'm pretty sure that'd put me up into fat-tire range... Still haven't really delved into that world just yet. Since the fenders are yet a dream--that would be premature. Also--to get ahead of myself further--I'm obviously not sure what rims might be the best in that regard. So, yeah... Fenders... Another planned refinement. I will want to paint them black.

                    Windshield. Another refinement.

                    I'd like to make the windscreen compatible with another as-yet non-existent refinement; a nylon removeable "soft-top". Something made of nylon tent-material, with folding fiberglass tent-poles for support. I'd like something that anchors to the top of the windscreen (or maybe straight to the box--should the windscreen be an integrated part--not sure exactly how it'll manifest itself just yet), and which comes together at the bakfiets' rear-rack--forming a sort-of isosceles triangle extending backward. One or more crossways tent-pole segments would keep it spread open. It'd have to form a higher-than-neccesary "hump" as it passes over the rider--because when turning, one side will have to "flatten" --as the far-edge of the box swings away from the rear-frame, while the other side would arch higher--as its box-side anchor-point moved closer to the rear-frame. The idea is to have some shelter, without it forming a "sail". That's why I thought of a triangular narrowing design--narrowing as it tapers to a point behind and below me. In that way, I'm hoping to prevent my design from causing a parachute-effect of unwanted wind-resistance... I have thought too about how it might behave in heavy cross-winds, wind-gusts, the blast of air from passing vehicles etc. To stabilize the "soft top" I expect some stabilizing anchor-ropes will be needed. Fortunately the bakfiets offers a plethora of potential anchor-points, so I believe in the end I should be able to make something fairly sturdy. Who knows though... The vision in my head is at least seeming plausable... So--that's also on my "refinements" list. Yeah, I can keep pretty dry with raingear, but it'd be pretty cool if I could figure out how to make a workable shelter-system for the driver--and I honestly think its doable--even if in practice, the idea turns out to be impractical. I think if I can make a crummy-looking but workable demonstration version, I should be able to take it to some "pros" and have them stitch me up a proper tent/roof/ragtop... I'd not mind a way to get a windscreen with a wiper; it rains like hell here. But then--I wonder if there's a Rain-X type product that'll work on a plexiglass scooter windshield... I bet there is... That'd be simpler, and wiser.

                    More to follow...
                    Last edited by tklop; 08-24-2019, 10:42 AM.


                      The brakes...

                      Brakes are important to this machine. Very important--especially the front-brakes, because the bakfiets is quite heavy, and because it has so be symmetrically balanced (in terms of braking).

                      Brakes have also been a constant source of woe, since I first met this [particular model of] machine.

                      Some background:

                      When my family was gifted my first bakfiets (the one with the flames--in the thread's title), it had one oil-fouled front-brake, and the other did basically nothing.

                      The brakes were among the first things I attepted to "sort out" as I gradually brought that old beast back into a rideable state.

                      The Babboe Big bakfiets was built for SA XL-FD (oversized drum-brake) hubs, in the front-wheels. But for some inexplicable reason, they designed it with the brakes' fulcrum-arms on the right-hand side, instead of on the left. So the brakes are actuated from the right-hand side of each front-wheel--exactly opposite to pretty much every other bicycle on the planet.

                      Obviously needing to replace the bakfiets' original wheel-hubs, I opted for dynamo-hubs, so I could eliminate all the throw-away batteries.

                      The SA XL-FDD (dynamo-versions) of these wheel-hubs turn out to be a little less tolerant of being spun "backwards"--though they lasted in fairness a very, very long time (in fact, they survived well into the electrification-phase of the project).

                      But eventually, the "backwards-turning" got to one of them. First probably a bearing got warm, then began to drag against its race--which then (because the wheels were rotating backwards), that race began to loosen. As it spun it way loose, it shed its bearing-balls, then the race itself shattered. Then, the hub proceeded to grind the dynamo to bits--shedding magnetic fragments as it went. Poor thing basically just disintegrated internally--as I limped it back home again.

                      This experience convinced me to go ahead and turn the wheels "the right way around".

                      But this also meant that I didn't have the built-in brake fulcrum-arm brackets; because they were over there on the wrong damn side of the wheels.

                      So, I attempted various arrangements, none perfect, but eventually got the brakes' fulcrum-arms effectively enough supported for the incredibly sturdy (and remarkably forgiving) SA XL-FDD hubs...

                      And then--came the All-Wheel-Drive mod...

                      I had no option for 100 mm dropouts, except disc brakes, roller brakes, or rim-brakes (which I don't have--and which would be impossible to "match" left-to-right). Lamenting the loss of my SA drum-brakes, I knew I had to face up to these limited choices...

                      I first opted to try roller-brakes. They're fairly tough, unlikely to "lock up" on you, and--well, they were an option on another model of 3-wheel bakfiets--so, I gave them a try.

                      But the lack of a decent bracket for the brakes' fulcrum-arm proved to be much less tolerable for the roller brakes. They worked briefly, but consistently hung up, and "dragged" --and subsequently wore themselves out in a ridiculously short period of time.

                      So--I decided I'd try discs...

                      And now--it's a mixed-report; some positives--but certainly more woes.

                      Discs don't use a brake fulcrum-arm, so that issue is gone.

                      But the bakfiets also doesn't have any mounting place for a disc-brake caliper.

                      So, I've tried some aftermarket brakets--to help bridge that gap.

                      The brackets do keep all the neccesary components approximately in place, but are not stiff enough to keep the calipers aligned to the disc--so after every application, they'll have flexed--and they inform me of this--in song. Even though they don't seem to cause any noticeable drag, I know that if they're singing, they're wearing pad-material away.

                      On the positive side of the ledger, the disc-brakes are extremely effective. The left-and-right balance is comparatively simple to maintain, and the 203mm discs provide far and away the most powerful braking I've had since the SA XL-FDD's... I love the performance--absolutely awesome!

                      But no--those brackets aren't stiff enough. So there's never really any way to get the brakes finely adjusted.

                      I have found one way to lessen the brake-noise. If I stop, apply the brakes, and then roll backward "against" them--it helps straighten the brackets again (somewhat). Then I'm able to proceed on my way, accompanied by a much softer brake-disc serenade...

                      Obviously none of the negatives there are as they should be--it is currently definitely not ideal. All that brake-singing means the same for the discs as the dragging did for the roller brakes--super-heavy wear. Now--that's actually not so bad with disc-brakes, as the pads are at least a snap to replace. But I don't want to have to budget several sets of brake-pads into my list of regular monthly expenses.



                      And the next chapter?

                      Well... Even though I really REALLY wanted the QS motors--I have some still-hopefully-pretty-nice DD hub-motors...

                      But DD motors bring questions... Questions that need answering...

                      Obviously I'm talking about braking in this post--so that's the topic here too, when it comes to those DD hub-motors.

                      I want to try yet another new braking option--regenerative / electronic braking.

                      If both 1000W DD motors could work together, I bet they could provide a lot of electronic braking effect.

                      As best as I can tell, the e-braking effect won't be able to take me all the way down to a dead-stop--and I'll defititely have to address that. The rear-wheel's SA XL-RD3 is very powerful, and can certainly handle "the last of the stopping" under most normal circumstances, but I'm not okay relying on it alone in terms of "standard use". No way. What a horrible feeling that would be--a "last-minute almost-no-more-brakes" effect. No, unless I still have discs, or rim-brakes--something else to "finish the job" on the front-wheels too--I just don't think it'll be safe.

                      But that last meter-or-so of stopping is not my only concern; not the only question that needs answering...

                      The motors do support regen and electronic-braking, as do their controllers.

                      Plus, my battery's cells can indeed take a high charge-rate (which can also be set and limited within the battery's 150A Bluetooth BMS).

                      But what will actually happen when two separate controllers are trying to "regen" my battery at the same time?

                      I'm guessing that it's not going to be a gigantic disaster--if both controllers are set to the same-level regen, seems they should be sending pretty-much exactly the same regen (charging) signal to the BMS. There should be little or no imbalance between the two controllers' "regen" sources--so (I am hopeful) that it'll be a non-issue. Since controllers cannot "cross-feed" each-other like batteries can, I don't even think there'd be any need for diode circuitry.

                      But I just don't know. I cannot be sure if any or all my assumptions are on target, or not.

                      So, ideally I'd like to poke around, and see if I can read up on the topic--see if anybody else has tried multi-motor systems with regen (I mean of course--outside the auto-industry)... On the other hand, it is a niche-thing--multi-motors... Maybe I'm the first nutcase considering going down this particular rabbit-hole, and it'll be therefore me who gets to be the "test-bunny" for the experiement. If so, I'll let you know--at least if I survive!

                      In all seriousness, if I do decide to experiment, and worse comes to worse, my battery's BMS has overvoltage/overcharge and lots of other built-in protections; and I'm hoping it will be able to protect the battery from harm... I am hoping...

                      Anyways--it'll be a while before I can afford to get those wheels laced up. In the interim, if I learn that multi-motor regen is either impossible, or impossibly dangerous--then I'll consider repurposing the motors (meaning maybe they don't get strung into 20" rims).

                      More to follow...
                      Last edited by tklop; 08-26-2019, 11:04 PM.


                      • tklop
                        tklop commented
                        Editing a comment
                        Temperature sensing... Dang... Yeah--I really did want that--but unfortunately, since the controllers I wanted to use didn't support temp monitoring, I decided not to have the temp-sensors installed in the motors. Now, it turns out I might use other controllers--that can support temp-sensing...

                        I know the temp-sensors--if they're akin to what a BMS comes with. They're tiny--and I might be able to tuck one in where the cable passes through the axle--without even having to open the motor up.

                        Even if not--well... If I burn them up--that'll suck. But at least they weren't expensive...

                        If the concept proves effective, I might try again--it's just that I'm quite limited in terms of options, because I'm stuck with 100mm dropouts.

                        For 100mm dropouts, I've found no DD motors with anything higher than 30mm magnets, and I've also found none with an aluminum stator--they've all got the (less-preferable, lower-heat-dissapating) stamped-steel stators. The ones I've got do have the preferred thin laminations at least.

                        I do not know if my 48V system versus yours at 72V will behave any differently in terms of the amount of heat produced... I do know lower voltage will mean less power--and it seems fairly safe to also assume it would mean softer electronic braking forces. Perhaps with less energy involved, there'll be less heat-stress. I do not know.

                        I may one day abandon my "modular" plans, and opt for a custom-build--encorporating the various lessons I've learned... If I do, it'll have room for an adult passenger, it'll have a lower center-of-gravity, and it'll also have some shelter for the pilot... But that's a long way off yet...
                        Last edited by tklop; 09-04-2019, 02:13 PM.

                      • calfee20
                        calfee20 commented
                        Editing a comment
                        I am using Grin Cycle Analyst dash boards. They monitor the temps. separate from the controller.

                        This controller company has a blue tooth module that interfaces with a smart phone and it can give you the temps of both the controller and the motor if the sensors are installed. I have one but have not used it yet so I can't give you a test report.

                      • tklop
                        tklop commented
                        Editing a comment
                        I'm going to bookmark that controller.

                        I like the BT.

                        I've got a couple 40A Cyclone BT controllers... I'm not sure if I'll be able to get them to work or not, but if so--they'd offer me good performance and options... I'm not sure if I can pair one device with multiple Cyclone BT controllers... Maybe only one at a time. That wouldn't help with temp-monitoring of both--though it would at least allow for setup and configuration. I'd have the same questions about the controllers in your link...

                        Since the motors are side-by-side, I could sort-of infer that the temp of one, is approximately the temp of the other--but to actually actively monitor both front-wheel motors, I'd need to be sure I can pair more than one controller simultaneously (monitoring maybe via split-screen apps--somehow--I dunno). Otherwise, I'd have to bring two Android devices along--one per controller--and that really wouldn't be ideal. Honestly, what sounds good about now--would be a dual temp-gauge--with needles on it--like for a multi-engine airplane. Maybe an idiot-light or a buzzer--for when either motor gets too hot...

                        The price of the motors I've got was quite reasonable (about $130 each--before shipping anyway). Because it's not a huge investment, I guess I sort-of see this as a kind-of "proof-of-concept" thing.

                        I know my DD motors are less than ideal--but that's also because all of the motors available for my dropouts are all of essentially the same less-than-ideal designs. They'll all be more prone to the very issues that temp-sensing, auto-shutoff etc. are meant to protect.

                        I get that.

                        Due to these inherent design-limitations, it seems as if I'm going to have to be fairly gentle with them most of the time, to prolong their service-life (with or without temp readouts).

                        Though perhaps misguided, my hope--is that this generally gentle use, will also mean that the risk of overheating is reduced--if not eliminated.

                        I know my bakfiets is a jumble of juxtapositions sometimes.

                        It's very heavy--normally, unloaded probably about 200 kilograms (with rider and battery).

                        But on the other hand, that weight is being propelled by three motors.

                        With my 350W (750W) geared-hub motors, teamed up with the 4KW Cyclone (+/- 2500W at my voltage) --when I've got that 4KW working together--well... That amounts to what--1,333W per wheel? That's a lot. The performance can be quite exciting; hang-on-to-the-handlebars exciting... And that's not really even peaking-out those front-motors for more than a few seconds--before I'm at my (unimpressive) 34 kph top-speed. Would not more powerful motors experience less stress--when working to provide similar performance? And couldn't that lower-stress performance also be available--from those more-powerful motors--with less heat-buildup? I honestly don't really know... I guess I'll find out.

                        I'm experimenting now, (still with the geared-hub motors) with some advanced settings--for slow-start and whatnot. Though I still woud not trust any other person at the controls, I do work to continue to "tame the beast" --though it remains quite powerful (the acceleration-curve isn't as steep, but at their peak the front-motors' displays still show each topping out briefly at 750W).

                        If I'm using similar "detuned" settings--with two 1000W DD motors up there instead--with the same three-level slow-start; even with low PAS settings; I expect they'll give me a very nice level of performance. If in general use, each operates in the 50W to 350W range my geared-hub motors do--to maintain my unimpressive top-speed; and if on the way up to that speed the DD motors only occasionally peak at 750 to 1000W --for annoyances like blue-smoke belching two-stroke scooters that I need to pass in order to breathe; or for other acceleration emergencies--like lahar-escaping or dump-truck avoiding; ---well... My thinking, is that usually, I'll be pretty gentle. And if I'm only pushing them hard like that intermittently--only on occasion--well... That's just not a lot of "hot-rodding"--and so I hope I won't face a lot of issues with overheat.

                        I intend to likewise experiment until I can find the lowest effective e-braking settings--to hopefully avoid a lot of braking heat buildup. If I'm anticipating my stops well, I'll still use almost no pad-material--and as long as I've full braking-strength available mechanically, that should minimize e-braking heat-stress.

                        Now... Loaded heavily? Maybe that's another story. And if I do decide to take the bakfiets on those "for demonstration purposes only" beach-runs, well... In those cases, I'll have to watch things closely, or I'll seriously risk cooking these DD motors--and I totally understand that.

                        I did get temperature-tolerance numbers from the motor's manufacturer too, so if I do find a way to add probes, I can make sound decisions off what the readout says. But even if I do cook them--I'm really not out a ton of money. Concept will still be proven, and I can then improve with the next iteration... Better to have done things right the first time... But still--next time, I want temp-sensors, and I want a "reverse-gear" function too (I can get temp-sensing on the standard controllers with the KT-LCD3 displays; or I can get my reverse-gear with the Cyclone controllers--but neither controllers have both).

                        October... Will be Direct-Drive month! :D
                        Last edited by tklop; 09-08-2019, 10:50 AM.