Well, today was a bad day as far as the bike kit goes. A very bad day, actually.
My first thought when I saw this kit was “48V, 1000W peak, “everything you need” and no torque arms? Hm. Of course, I had to wait until I got it to make any determinations. (Most of you already know where this is going, right?) Once I got the kit, and got the wheel really well torqued into the frame, I decided that perhaps the kit didn’t actually need them. Of course I still planned to add them, but checking the axle nuts every day it seemed like I was doing ok. Until today. Less than 5 miles after putting the wrench on those axle nuts again, it happened. I was starting off under pedal before getting into the throttle, as I’ve become used to doing. I got up to maybe 8 MPH and rolled on the throttle. I had a sharp turn coming and didn’t expect to exceed 13-15 MPH until making the turn and getting onto the straight. Shortly after rolling on the throttle, maybe at 10ishMPH, the axle rolled out of the (chromoly) fork. The forks bit the pavement, I bit the pavement, and the bike came up and over me, landing on the battery box/seat/rack/rider (that’d be me). Fortunately, I’m not too hurt. Some cuts and scrapes, a sprained thumb, but overall I’ve had worse. Then again, I could have a crash that resulted in waking up in an ambulance and that alone would not necessarily make it my worst, so saying I’ve had worse is not saying a lot.
Anyway, after I got up and attended some of the bleeding, I looked at the bike. The axle seemed to have wrapped the cable a couple times, but not too many times, and not tight. I had plenty of slack above a Velcro tie-strap on the forks, and it pulled the slack through the strap, and never got tight against anything else. The entire wire/hub interface looked good. I was hopeful.
I looked at the battery box. Dinged, and moved on the rack, but didn’t look too bad. I figured if I had an issue, it was probably there. The fact that it moved on the rack didn’t mean much, since it does that from normal riding @ 20 MPH when I hit rough pavement sometimes (again this is not the final rack, so that’s not a dig at the kit). All the connections even appeared OK, aside from the fact that as the battery slid back it unplugged the main power wire. Not a big deal. Now I just had to get the bike the rest of the way to work.
Once at work, I connected everything again. Battery gauge is reading only 1 light. Bad news… I only rode 5 miles on it, and pedaled/hypermiled quite a bit. When the crash happened it was still reading 6/6 lights. I hit the throttle and the one light it had went away as the motor stutter-stepped very slowly, 1-2 MPH if I were to guess. This is where the good news starts, at least for you guys. You now get to see the innards of the thing, after a few hundred miles of riding. Mind you, I have not yet ridden in the rain (although I would have, with the controller in a bag, later down the line as part of my testing). I have had to ride on wet roads.
So, first thought was a loose connection in the battery itself. A wire to the BMS, a solder tab, a wire off the battery, something in there, right? Wrong. Opened it up and checked everything carefully. No loose connections I can find (no multi meter here, so I can’t check actual voltage). What was surprising was corrosion on the battery, as well as some moisture inside. I really don’t think this is the issue as it worked fine right up to losing the front wheel, but it was still surprising to see the amount of wet & road dirt that had made it’s way into the box. I’m thinking that in the future, sealing the openings on the bottom of the battery box or riding with fenders would be prudent. So, without further ado, I present to you the innards of the battery, including the BMS:
First pics, battery box opened up
Seeing no problems there, I opened up the actual battery. This is where we can see the corrossion setting in, but again, all the connections are still solid, much to my surprise (and somewhat to my dismay, since I think that would have been the easiest fix). I also don’t think the corrosion is the problem, since the issue started with the crash, and not after sitting overnight after riding home on a wet night or something.
So, on to the BMS
And with everything again looking solid and no loose wires to speak of, it’s time to open up the controller (which was very well sealed, and had a pretty smart design. I was impressed opening this up).
Now for the downside: I don’t know what the problem could be. The battery appears to have held up to the hit, which surprised and impressed me. There’s a lot to be said for these solid rectangular cells against each other. With so much contact area, there’s no shift (especially in a solid metal box like this one) and even though the battery box was one of the things to impact the ground as the bike cartwheeled @ 10MPH, all the solders, tabs, etc. seem to have held together quite well. The BMS also looks fine. The Controller doesn’t appear to have any issues. I’ve examined all the connections, and they all appear OK. Could be something in the actual motor/wheel, or could be I missed something in my going over the kit. The fact that the battery life indicator is reading a mostly dead batter makes me wonder about it being an issue with the motor, though. I just don’t know.
<this section edited as I found a multi meter, as told in my next post>
My primary thought on this is that for the 48V kit especially, Fusin/WWEB should really consider adding some wheel retention. Torque arms I’d assume, but something more than the supplied gear. With a better way to secure the front wheel, they would have an absolutely amazing product. The range I got was awesome, the power was always there, and the speeds were enough for me. It’s a shame it didn’t last long enough to do more testing.
I’m really disappointed. Yeah, I’m bleeding a bit, can’t really use my left thumb, and ruined some work (dress) clothes, but what I’m most disappointed about is being unable to figure this thing out. I really wanted to ride home tonight, and ride it to the motorcycle races this weekend. I suppose the fact that my primary disappointment (considering my injuries and destroyed clothes) is that I can’t ride the bike again tonight, and all weekend, says a lot. I really hope I can fix this thing. If I can, I’ll find a better way to secure the front wheel. I’m not sure what, maybe a new set of steel forks that the axle fits into better, combined with torque arms? If I can’t, I’ll miss this kit. It was only a short time, and a few hundred miles, but I already have become attached. We had plans! A mere 40 hours from now we’d have been arriving at the motorcycle races! We were supposed to ride home tonight, with me pushing the flats and downhills and the bike taking the hard acceleration and climbs! I tell you, we had plans! It’s too soon!
