No announcement yet.

Bakfiets earns its flames!

  • Filter
  • Time
  • Show
Clear All
new posts

    It's ALIVE!

    Okay--well. Far from perfect, but the bakfiets rolls again, under its own power.

    The new waterproof-motor extension cord is flawless and ideal. There's no more ugly "wart-lump" on the side of the rear-frame; it looks nice and clean.

    One day, I'll get some pictures up here.

    Oh, but as alluded to earlier, I'm far from done with the insanity...


    I located some innocent-looking little 48V 350W hub-motors (with a nice steep 1:11.4 gear-ratio for lots of torque). These motors come with a roller-brake. Per my previous postings, I'd really prefer drum-brakes. But from what I've seen available out there on the market, I'd need at least 135MM dropouts for any geared motors with drum-brakes I've found (so far). A compromise was in order.

    The motors will top out at about 28 KPH, just about exactly what my current "cruise" speed works out to be with the Cyclone (my latest rear-sprocket shifted the digits a bit from before). That's actually pretty much perfect. I'm almost never going to want to go faster than that. It's really just pointless and only attracts a lot of unwanted attention when I do go faster. I mean--it's nice to have it "in-pocket" so to speak--and I do. If I click the 3-speed switch over to "high speed", I'm right back up to +/- 40 kilometers per hour. But as I mentioned previously, I know if I avoid excessive "hot-rodding" my parts will all last a lot longer between fixing sessions.

    One goal in this project has been the idea that the whole electrification kit--the "powered bits"--could be modular; fairly easily swapped over to another Babboe Big bakfiets, should my current beloved model finally rust away. So, yes, I could cut and weld the bakfiets' frame, to make room for nice drum-brake hub-motors to fit, but honestly--it's not worth the effort--and it'd be something I'd need to repeat in order to "shift" my parts to a new(er) bakfiets. So, no. I don't think so. I'd rather all my components remain as "hot swappable" as they can.

    Some history on me--and my (probably unjustified) roller-brake prejudice:

    My ex has it now, but we used to share a Giant Mio--a so-called "Mama-Bike" (Mamafiets). Though it held out for the first couple years, I trashed the back wheel's roller-brake on that bike. My ex and I broke up before I got it changed out, so I never got a good look at it. It is possible that brake may have had other issues besides "heavy use" that contributed to its demise, I will freely admit that I just do not know. But fair or not, ever since that one started to go, I've felt less than confident in them.

    That Giant Mio is a heavy-ass bike to begin with, and then with the two kid-seats installed, a rack-extension, and room for two large shopping bags besides--it's big-already-turned-monster--and in fairness, quite a solid and capable machine! I used to be a stay-at-home dad. When I had that bicycle loaded with both kids, and groceries, it was pretty hard to handle sometimes. As you can imagine, it was incredibly top-heavy, when compared with a motorcycle, so it was really hard to hold up whenever it started to "go". Of course this was always when I was standing still--trying to load, or unload, or trying to get started moving. At speed, that thing was fine. Honestly--my best description would be to say that bike rode like a pickup-truck. Loaded, unloaded. I'm telling you! Anyways, it was not up at speed where the struggles were the worst--it was when stopped, or barely moving. I'm not one to brag--hell, a quick glance will tell you why. Yet though I'm pretty lean, I am reasonably strong and fit. It's not a lie to say I'm actually in a lot better shape now than I ever was during my active-duty time in the Air Force! But even so, that bike scared the heck out of me a few times, to be honest. I just couldn't out-wrestle it if it went too far over.

    Because when loaded, and with rider, that bike had almost all it's weight over its back wheel, I couldn't get a lot of braking power out of the front-brake, without causing it to skid (and though recoverable, let's face it--front-wheel skids are all kinds of no fun). So, that poor back roller brake really took a beating. There's no doubt about it. But my drum-brakes wouldn't ever have failed--and so that's why I'm not so trusting in the roller-brakes.

    So, once I got the initial safety issues sorted out, the Babboe Big bakfiets was a big plus in that regard. I could haul both kids and six big grocery-bags. Or I could pick up a baker's dozen square-foot-size concrete paving stones--or twelve big sacks of gravel... I've hauled all these and more (along with various assortments and combinations of my kids and their friends) unassisted in the bakfiets. I've taken my kids to the zoo--on leg-power. Three times, actually (and from that old house it was about 35 kilometers round-trip). Rah, rah, leg-power, right? Or is it more, "Oh, my aching knees!" I'll admit to feeling a lot of both. I've hauled my 100lb+ toolbox to another city to help someone with their household repairs, and finally, when my ex and I broke up, and I moved out--I actually moved to my current city with the bakfiets (still pre-assist). It has been a handy thing--and now made much handier!

    Anyway, I'm hoping the roller-brakes up in front will be alright. The latest year's model of Babboe Big bakfiets is being sold with roller brakes on all three wheels, (their e-bike version or the regular leg-powered version like I've converted)--so the manufacturer must think they're okay. Roller-brakes will have a lot more braking-leverage when mounted on smaller-diameter 20" wheels like on the front of the bakfiets--versus the stopping-power they offer the 28" wheels on my city-bike. And my city-bike stops quite successfully with them. So, there's those positive points coupled with the fact there's two of those roller-brakes working together--because there's two front wheels... I don't know. On the balance, maybe it'll be alright.

    I just hope the roller-brakes won't be over-stressed if I'm trying to stop while I'm hauling a load. In brake-failure, there's always the back-brake... But... In those instances, the back-wheel's brake is just over-matched by the situation, and thus not much good on its own. I mean--I'm sitting almost over the back wheel, and I can squeeze the handle awful hard, and get that wheel starting to scuff--almost to the point of skidding--but the stopping distances feel comparable to those of a train. Not so good, in other words. It has happened before, and I just start looking for soft things I can crash into, while waiting for the speed to scrub off... "Hmmm... Light's red. No, I better not smash up that sports-car. No, the ditch is out--I don't want to get the bike wet again... oh-no-time's-a-runnin-out-here---I wonder how much those bushes are gonna hurt me?" (brace, wince-for-no-helpful-reason, crash, etc.) Makes me lament that I can't just effin' down-shift for some engine-braking--or leaves me wishing I had an anchor to toss out! But moments like those also make me grateful for powerful and reliable brakes.

    So, yeah. Three-wheel-drive! No more thoughts or plans for jack-shafts, no need for any cutting and welding. Should be pretty much plug-and-play. I'm going with as-simple-as-I-can for now. Two motors, two controllers; one throttle, and a shared on/off switch for the front-wheels' controllers.

    Though I may wind up needing to use two throttles; one throttle for the front system, one for the Cyclone mid-drive; I will experiment with using just the one throttle; powered by one controller, then splitting and sending its signal-leg to all three controllers.

    These cute little motors I found can be programmed with their display, but then after that, the display can be removed. The system doesn't need it to operate. That's really handy for my application. I need to be able to adjust those motors' settings, but as long as I make sure the two match when I'm through, I can do that one-at-a-time using my one, single removable display. Then, when I'm done, I can plop that sucker in a nice safe little box, or in a drawer, in the house if I want to--or perhaps in the "long-trip" toolkit. But it won't have to hang out in the rain on the handlebars!

    Since it'll be a while before those new motors and other parts arrive, there's more time to fantasize, or formulate plans:

    I'm unsure whether or not I ought to just get a couple new 20" Ryde Andra 40 rims, new spokes and nipples--and then just build those wheels up as a complete separate set. The thing is, if one front-motor has a problem, both are really rendered unusable--due to that "adverse yaw" issue mentioned earlier. So--having two complete sets of front-wheels (one powered, and one non-powered), all ready to go--as a quick-swap--might be pretty handy. Besides, I just got done rebuilding those front-wheels (after the swim), and it feels wrong to take them apart again so soon. It's less labor to build a new wheel than it is to rebuild an old one--so there's that. It's also a money-thing, although those rims I want aren't unreasonable (and they're the strongest 50+KPH e-bike certified rims available on the planet--for the moment). And, it's a storage-thing, because right now I haven't any. I'll probably do it anyway, and just hang the spares from the ceiling if I have to!

    I'm curious if this mod will help with stability too. Will this system make the bakfiets want to "pull itself through" the corners--like a front-wheel-drive car? I'm guessing, partially based on how it handles right now, that at least in circumstances where you could be "on the throttle" some through the turn, it just might. If so, then I think the front-wheels' pulling-action would also--under that same light power--also make the bakfiets less tip-over prone. That would be awesome--as this is its greatest vulnerability.

    Speculation is fun, but there's no telling until the first test-run. Whatever it ends up doing, I'll be able to adjust both front-systems to match one another, and then I'll be able as always, to adjust the Cyclone mid-drive system separately. If I want to play around with balancing power between the two systems, plenty of fine-tuning should be within my reach.

    I sure do want to make it clean and simple. One throttle is my goal, with the ability to use the systems either together, front-only, or Cyclone mid-drive only.

    As I fantasize about the places I might be able to reach in an AWD bakfiets, I know I've got limitations. Or rather--the bakfiets does. Ground-clearance is a little limited under the center-line, and it'll never make a very good bulldozer--so it may not be wise venturing with it into the really deep mud. But the beach is calling my name!

    In any case, I bet I can have a lot of fun, and go a lot of places nobody else would dare try to take their bakfiets into.


    I've got wheels to true. Those first few rides on a freshly-built wheel--seems some of the spokes always start singing their praises, don't they?!

    Take care, everybody...

    Last edited by tklop; 16 hours ago.


      And today it went to the beach and back (+/- 100 kilometers)

      The lump on the handlebars is a powerbank for my phone (which is taking the picture). I've still not set up my 12V system--so it's that, or risk a dead navigation device.

      I had tried a selfie, but I decided to spare you all the horror.

      Take care, everyone,

      Last edited by tklop; 4 days ago.


      • tklop
        tklop commented
        Editing a comment
        I did not attempt the soft dry sand. I do not think any amount of "run at it" would've gotten me through with only 1 wheel pushing.

        However, on less loose sand, on some horse-paths, back near my ex's house, I did find that the bakfiets had the power to plow its way through. In 1st gear, with max throttle, and the three-speed switch set to "Low" I had the most controllable balance between needed power and required speed to keep from "digging in" and bogging down. It felt pretty amazingly bad-ass. I first tried it on my own, and then with both my daughters in the box a little later on. I'm a strong rider, but I physically cannot ride these trails on a mountain bike successfully. Every ten or fifteen meters, I wind up either falling down, spinning out, or digging in, and usually within the first total twenty meters or so, I'm just completely running out of steam. That's the kind of trail-surface it is. I mean--no big deal, it's not for bikes--it's for horses--so, yeah. Duh. But it's a good measure of the Cyclone's performance, to be able to push this front-heavy beast down a path like that--torn to hell by horse-hooves--was my point, I guess... The Cyclone 4KW motor--even "turned down" is a beast--I can testify!

        Which makes me have to believe that 3WD is going to be absolutely amazing...

        And it makes me glad I went for the 48V 60AH battery. I just figured--first time project--to get as much juice as I could afford to, esp. considering the weight of the bike I wanted to power. But now, I see how good a choice that turned out to be. Exploring is a blast, and will be even more interesting, the further off the beaten path I can get... But exploring is not so energy-efficient as gliding over well-groomed asphalt. Yet even after riding about 40 kilometers to my ex's house, playing in the woods with the bike, more with the kids, going on a "forest tour" (of another twenty or so kilometers, mostly off-road), I still had enough to get back home, and showing another 40 kilometers left 'in the tank' according to the BMS.

        Days like these ones--with trips to the coast; or with visits to my ex, to take my kids on a tour of their forest; they all add up to make me more confident in my bike's capabilities, and the Cyclone's sturdy reliability.

        I'm really enjoying the heck out it!

        Take care,

        Last edited by tklop; 15 hours ago. Reason: for clarity