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    #61
    I got some new fenders. Round galvanized-steel trailer fenders--13 cm wide. They were the only ones I could find in that narrow-width--which is exactly perfect for the bakfiets.

    But the radius was just a bit too small. The "factory" Kenda tires would've fit just fine under them, but the much larger Super Moto-X tires--definitely didn't...

    I fixed that.

    I took an old bench from the original bakfiets, and placed one fender on top of it--arching over the bench--then placed the other on the underside of the plank. Then, I wrapped a cargo-strap around them, and ratcheted down. I worked slowly, repositioning, re-checking--I took my time--but bit-by-bit, the fenders were "spread open" a bit wider in this way. Now they're just exactly the radius I needed--and because I squeezed them simultaneously, they both continue to match one another perfectly.

    They're stock trailer fenders though still--and not a perfect custom-fit. They'll not go as far down the wheels as the original bike-fenders did...

    To deal with this, I'll rotate the fender-arches backward, until they meet the rear frame-supports. This will leave each fender with an open gap on the front--sort of like a jeep... I think that'll actually look okay--if not pretty cool. I think I'll try to make a removeable plastic mud-guard to bridge that gap for on-road use--especially in inclement weather--so I can help keep the road-spray and silt from getting everywhere--but I think I will want that mud-guard to be something I can just pop back out again.

    I think the fenders are going to look good, but at least I know they'll be effective. And due to my squeezing-modification, they won't be at risk of rubbing on my tires--as the stock ones currently still are.

    They do disrupt the appearance of the bakfiets though. They'll be a whole lot of silver shiny steel--unless I paint them. I think I'd like it if they were black--like the bakfiets' frame... I wonder how much powder-coating costs...

    More to follow...

    [edit--appended]

    Fenders... Are going to be really cool...

    But I also need to arrange for the inboard-sides--what would you call that--fender skirts?

    Anyway...

    I've got indoor storage (thank heavens).

    But even so, the bakfiets is made of wood. It's pretty-good quality weather-resistant wood--but even so, its vulnerable. All that wood dries out better, if it's not caked in mud or sand--and that's why I want the inside of the fender-wells shielded somehow.

    I'm not scared (obviously) of adapting "non-bicycle" parts for my project. Sometimes it's ridiculous, other times it's just the thing. Basically, I'm looking for a plastic disc of about the right radius, which I can halve--and slip behind the fender, on both sides. Ideally, I'm looking for something that can be a little textured on one side. The idea, is to put that textured/pattered side against the box--with that relief providing some air-space between the layers. If water were to be trapped between plastic and wood--that'd entirely defeat the point of the fender-liner. I could also anchor it with some washers on the backside--to let it breathe. Anways, I'm not committed to any particular solution yet, but I saw some gigantic plastic trays, meant to go under equally gigantic tree-size flower-pots (would you call them tree-pots?)--I'm obviously not a gardener... But I thought maybe, with minimum modification, perhaps I'd get the properties I'm looking for. Keeping my eyes open.
    Last edited by tklop; 09-08-2019, 08:02 AM.

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    • tklop
      tklop commented
      Editing a comment
      Knowing that I'll have some extra room underneath my new fenders, I've been poking around to see if I can find any other tire-options for my machine.

      The bakfiets has no suspension, so obviously all the ride-cushioning has to come from its tires. For non-suspension bikes, balloon-tires are one decent way to tame the severity of the bumps. For my 20" front-rims, the Schwalbe Super Moto-X tires [erto 62-406] running at +/- 55psi are currently (as far as I can tell) the best option out there for my front-wheels. I haven't been able to find any other tires with equal (or greater) air-volume.

      The next-closest ones are in the family of high thread-per-inch high-pressure BMX Street/Ramp tires. Those tires typically lack any leak-protection, but are otherwise in many ways really great tires--depending on the application. I've used them on the bakfiets before--back when the machine was "me-powered" (non-electric). Street & Ramp tires are really awesome in terms of super-low rolling-resistance, and are excellent for on-asphalt grip... But without suspension, they're hard as rock, and feel as though you're riding on wooden wagon-wheels. At e-biking speeds, that's horribly jarring--and completely unacceptable. Eliminating those 20" Street/Ramp tires, from my list of viable options, leaves only a scant assortment of knobbies...

      As of this posting, I haven't yet been able to find any balloon tires broader than those Super Moto-X's; and I haven't found any "fat-tire" options whatsoever.

      Of course new products come along all the time, and I'll keep my eyes open. But for now, I'm sticking with my 20"x 2.4" 62-406 Super Moto-X's--at +/- 55 psi.
      Last edited by tklop; 09-15-2019, 12:22 AM.

    #62
    I have a KMX trike that has 20 inch front wheels. I put a set of Super-motos on it and they are great. You don't need that much pressure either 35-40 psi should be fine.

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    • calfee20
      calfee20 commented
      Editing a comment
      You have me thinking now. Maybe I should put a bathroom scale under my tires and see what the weight distribution is. I don't know maybe just more useless information.

    • tklop
      tklop commented
      Editing a comment
      I think the weight-distribution / center-of-gravity data might be interesting to see. The most useful data would be "including rider" --and then perhaps "rider plus cargo" (various configurations, if applicable).

      I'm imagining it might be hard to read the scales when seated. If you leaned and twisted in order to see the dial, you'd affect the readings. Perhaps another human would make that a lot easier... Telescoping mirror maybe--but then the readout would be backwards... Surmountable challenges.

      You could also take weight-measurments with the trike parked along a slope to simulate the weight-distribution while cornering (and if you were really good at math, you could likely extrapolate--though I'd not know where to begin).

      Maybe you're right. Maybe the information would be ultimately impractical, or useless... But yeah--curiosity sometimes demands answers anyway!

      Now I'm going to have to go buy a bathroom-scale myself!

    • calfee20
      calfee20 commented
      Editing a comment
      Don't go that far.

    #63
    A quick note:

    Two more e-bike conversions launched into the world... Both belong to my ex...

    First, a 28-inch wheeled Batavus Yakima--which isn't gonna last a lot longer (due to corrosion mostly). It's a 48V system, with a 15AH LiFePO4 rack-battery, powering a 350W Suring front-wheel hub-motor, with KT-LCD3 display, throttle, and PAS. That's my ex's daily-commuter bike. I wanted to do a TSDZ2 mid-drive, but the bike is in too poor condition for that. When it dies, I can swap the front-wheel hub-motor to her next bike, or convert that next one to a TSDZ2--whatever works out.

    Second, a Giant Mio -- Mamafiets (Mamma-bike). That one is another 48V system--this time with regular Lithium Ion 18650 cells in a fish-battery, powering a 750W TSDZ2 mid-drive. Barely fits. The nature of the frame, means the motor really can't swing forward and up--and in fact, there's no room whatsoever for the rear-support bracket. I've got everything tightened down, and if needed, I can always manufacture a new bracket, or even potentially machine down the existing one until I can make it fit, but for now--I'll just see how it goes.

    More notes may follow on these two builds.

    That makes a total of five bikes I've now made electric (though the thee-wheel-drive bakfiets should almost count as three separate conversions--I've still only counted it as one).

    I'm not a pro at this--and I don't want to be. But I generally satisfied with my results so far.

    Comment


      #64
      Originally posted by calfee20 View Post
      I have a KMX trike that has 20 inch front wheels. I put a set of Super-motos on it and they are great. You don't need that much pressure either 35-40 psi should be fine.
      I've dropped that PSI--and have ridden for a while that way now. Yep. Better. Much better. Thank you!

      October didn't end up being DD month. Maybe November.

      I hope they're quieter.

      The banshee-wail of the geared-hub motors is a bit much. I love their performance! But the noise sometimes startles the hell out of people--other times clearly annoys.

      I hope they're quieter.

      Comment


      • tklop
        tklop commented
        Editing a comment
        I'll see how they do with the stock controllers (KT48ZWSRK-TY01C is the model, rated 22A continuous, 45A peak). What info I can find lists them as sine-wave, but I'll just have to try them out. If they're awfully loud, then a controller upgrade isn't out of the question.

        I'm intrigued to see how they work out too--with regen... I suspect that when it comes to regen, my added intertia (because my machine is so heavy) may mean I get a lot more value from regen than most bikes (which would be featherlight in comparison). If that proves true, and regen proves successful, I may eventually set up a trailer with DD's--using them exclusively for regen and braking. If inertia is my freind--when it comes to regen--then a regen-trailer might actually work quite well--when loaded down (it would obviously be frightfully dangerous to power a trailer).

        Crazy stuff I think about...

        Soon I'll get those wheels built, then give it a try--and then I'll start to get some answers. Speculation is fun--but I want to get to testing!
        Last edited by tklop; 4 days ago.

      • calfee20
        calfee20 commented
        Editing a comment
        My trike and my bike have the same 18 fett controller but the trike has a 35mm stator and the bike a 45mm stator. The windings are also slightly different to with the 45mm having a winding for a little more torque. Anyway the 45mm motor has an insane amount of regen "braking" it was almost like slamming on the brakes. I had to go into the programming and tone it down. Both bikes are about 100 pounds, 45 kilos. That will be 350# with me on it.

      • tklop
        tklop commented
        Editing a comment
        My DD's are 30H which should be less severe than your 45H's (I assume). And the rig is comparable to your trike--maybe a little heavier... But with two of them working together, I do expect the braking could be quite strong (though I doubt it'd be a linear comparison--when added together, that's 60H worth of magnets under my cargo box). I requested the motors for high torque, low top speed--maybe that'll also make the e-braking more severe.

        Fortunately, I've got nice heavy bar-stock type steel dropouts--about 1/4" thick steel. I'll get them locked down one way or another!

        I intend to delve into the programming. The controller's programming guide says that the "best regen" setting offers the least e-braking; and as the e-braking incrementally gets stronger, the regen becomes less and less effective. This at least seems to imply, that some sort of double-compromise should be attainable--selecting perhaps the second or third best regen-setting, while being sure I've adequate braking (the discs can take up the task for emergency stops). If the braking isn't too severe, I don't expect it'll cause much overheating either.

        I've found that even with the 350W (which are actually 750W) geared-hub motors---when I've got two motors pulling together, they deliver a heck of a lot of power. I'm hoping at least--that by teaming the front-wheels up, the e-braking force will be similarly enhanced; allowing me to select a fairly soft e-braking setting, and hopefully leaving a semi-decent amount of regen effectiveness. My plan also, is to adjust my riding style--to lengthen my stopping distances; hopefully turning as much of my intertia into regen as possible. I'm eager to experiment.

        If budget constraints allow--I'm going to drop the motors off at the wheel-builder. (short tangent) Being in The Netherlands is pretty awesome. I've got a shop just across town, does nothing but build bicycle wheels... Next-day delivery or pick-up. How cool is that? This place is about as bike-friendly as any place could ever be! You can bring in your own hub, even your own rim--or order from their extensive in-stock warehouse. And--it's so cheap, that I see zero reason to attempt to build my own wheels ever again. Awesome!
        Last edited by tklop; 4 days ago.

      #65
      Got the DD hub-motors dropped off for building today. When they're done, I'll still need to swap controllers in order to make the install work. I might also need to swap to another type mechanical disc-brake-caliper (ain't much clearance on the wheel-side of the disc)... I'll have to see how tight it is--perhaps swapping the DD motors' screws for a style with a lower-profile head (round-head, or pan-head might work better) --if lucky, perhaps that might be enough... With every advancement comes new hurdles--naturally.

      DD motors will mean another slight improvement in terms of stability. They're heavier. More weight at the wheel-axles, shifts the center-of-mass lower (even if only slightly). Every little bit helps.

      I have tried to imagine ways for further lowering the center-of-mass. Perhaps I could do a floor-battery----that is, lay out say 72V and 200AH (or maybe more) worth of LiFePO4 cells--basically covering the plywood floor of the bakfiets--maybe one layer of cells, maybe two--then drop another plywood floor on top--turning it into a plywood-battery-sandwich. Wire it all together, with the BMS in my electronics-bay (under the bench). That'd be pretty awesome.

      Also: Speaking of batteries...

      Since repairing my 2nd suitcase-battery, I've been doing some various runs with it. It too has a Bluetooth interface, but doesn't display speed, or distance, or effieciency--or really anything all that terribly useful. It seems to be doing alright. I can punch both throttles, max-demands from all three systems, and there's no issues at all. The BMS isn't even getting hot. So--yeah... So far, so good.

      I need to really stretch it out one of these days--and see if I can determine what its effective range is (and calculate its "real" versus advertised capacity).

      More to follow--I'm sure.
      Last edited by tklop; 1 day ago.

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      • tklop
        tklop commented
        Editing a comment
        From what I can gather, the following things seem to be true when it comes to regen--in bikes anyway:

        We've got two separate things gong on, "Regen" and "E-braking"

        From what I gather, regen--is binary; it's either on, or it's off--and on its own, regen doesn't provide much braking help--not much rotational resistance at all.

        And it's my understanding that electric braking forces don't help regen at all, but actually consume battery-power--reducing the effectiveness of regen with each progressively stronger setting.

        If those assumptions are correct, I believe I will be able to recover more energy than average, for a couple reasons:

        1) I have two-wheels working together. Logically, I'd assume that at any given rotational speed, I should be getting double the regen--with two wheels regen-ing--as opposed to only one.

        2) I have a lot more inertia to work with--which means I can brake earlier--increasing the length and duration of coasting/braking regen-periods. By taking longer to stop, I expect greater energy-recovery results.

        Now---if it turns out I'm wrong--and none of that matters at all, and I only get what most users are recovering--that is to say between 5% and 10% generally speaking--I'll still be totally happy with that.

        I've just got the feeling I'm gonna do a little better.
        Last edited by tklop; 18 hours ago.
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