Well I have had this bike for over 3 years and run a rwd 1500w leaf ebike kit on it 29" it was a walmart Genesis frame and now the thicker gauge spokes on the hub motor some have a small bend in them. This bike only has minimal front suspension and I do run my 18650 battery pack on a rear rack :-( the roads are rough where I live and the bike goes 40 mph when I want. I am also not light at 6'2" 215 lbs. Any suggestions on what you would recommend in a good price range from here? I build everything (battery customize the bike install the kits etc) besides the actual ebike kit which I usually solder the shunt in the controller. Front tire is a stock 29" no bent spoke but not much weight on it unless I am under heavy braking which I upgraded the front discs/pads. I run a partial kevlar tire in the back to increase the strength from the weight.
Bending spokes on hub motor please help
- Thread starter mightbaal
- Start date
markz
100 TW
What size spokes have you been using?
What is the total weight including you and cargo?
Best to stay with 14 guage spokes or the double butted 13G/14G spokes because you want the flexibility. Buy good quality spokes and rims. I have used the Crystalyte rim from Grintech www.ebikes.ca with great success. If you can find the Alex DM24 that is also a great rim, along with the Sun Rhyno Lite rim and the MTX model rims like the MTX33. Lace it in the 1 cross pattern and use Spoke Oil or Boiled Linseed oil and stress relief the rim once its laced.
There are guys in this forum that are or have been much heavier you. I am up in the higher stratosphere of the 300's but the fat is stretched over over my 6'5" ish (I tend to say that # but perhaps a touch taller) Plus the fat stretched out part doesnt hurt my ego as much. :wink:
What is the total weight including you and cargo?
Best to stay with 14 guage spokes or the double butted 13G/14G spokes because you want the flexibility. Buy good quality spokes and rims. I have used the Crystalyte rim from Grintech www.ebikes.ca with great success. If you can find the Alex DM24 that is also a great rim, along with the Sun Rhyno Lite rim and the MTX model rims like the MTX33. Lace it in the 1 cross pattern and use Spoke Oil or Boiled Linseed oil and stress relief the rim once its laced.
There are guys in this forum that are or have been much heavier you. I am up in the higher stratosphere of the 300's but the fat is stretched over over my 6'5" ish (I tend to say that # but perhaps a touch taller) Plus the fat stretched out part doesnt hurt my ego as much. :wink:
Markz's advice sounds good if you're building your own wheels, but I think you may have a more basic issue:
Spokes work in tension, not compression, so a bent spoke to me implies that you may have lost tension. Have you checked your spoke tension?
My cheap chinese front motor wheel came with really low tension from the "factory", which also gave the spokes a tendency to spontaneously loosen. Interestingly enough the rim stayed basically true even with quite a number of completely loose spokes (loose to the point I could turn the spoke nipples by hand)
Spokes work in tension, not compression, so a bent spoke to me implies that you may have lost tension. Have you checked your spoke tension?
My cheap chinese front motor wheel came with really low tension from the "factory", which also gave the spokes a tendency to spontaneously loosen. Interestingly enough the rim stayed basically true even with quite a number of completely loose spokes (loose to the point I could turn the spoke nipples by hand)
MadRhino
100 GW
If spokes are bent at the flange, they will start breaking soon. If they are bent at the cross, they will last. Some lacing jobs are good with over-crossed spokes, meaning the spoke that should normally cross under, is intentionally crossed over to force a bend. The bend at the cross is distributing the tension on 2 spokes, thus require lower tension to build the wheel. Not very aesthetic, but efficient when spokes are big and the rim thin. The right way to do in that case, is to use rim washers but that is PITA when the rim is double wall and rounded. That may be the reason why the spokes have a bend in your motor wheel. If the bend is at the flange, it is a shit job. If the bend is at the cross, even on all spoke pairs and the wheel true, you have a good wheel despite its ugly look.
If they're thick spokes (common for 12g or higher to be used on hubmotors, even though they shouldn't), then you can tighten them but most likely they can't be tightened enough to keep them tensioned correctly without damaging the rim.
Replacing the rim with one that can handle the tension the thicker spokes need is one option, but using thinner spokes (14g, or 14-15 butted) of a good name brand from a known good source (like Grin Tech, Danscomp, etc) is a better one.
You can use thicker ones but 13-14 butted is the thickest I'd use without getting a rim designed for thicker spokes. That's what I use on my SB Cruiser's rear wheels, with the same kind of rims an old Zero MC model used, and I have yet to have spoke problems, even though potholes/etc have broken axles and bent rims. (and I've reused the spokes on each new wheel...not recommended but they've worked fine so far).
Keeping in mind my trike abuses the wheels a lot more than a typical bike, almost anyone would be find with thinner spokes 14-15g butted, and have a much better tougher wheel.
But anyway, the thicker spokes are generally the main cause of the problems described in this thread so far. (because they can't be tensioned sufficiently without damaging the rim, which then lets them loosen...).
Replacing the rim with one that can handle the tension the thicker spokes need is one option, but using thinner spokes (14g, or 14-15 butted) of a good name brand from a known good source (like Grin Tech, Danscomp, etc) is a better one.
You can use thicker ones but 13-14 butted is the thickest I'd use without getting a rim designed for thicker spokes. That's what I use on my SB Cruiser's rear wheels, with the same kind of rims an old Zero MC model used, and I have yet to have spoke problems, even though potholes/etc have broken axles and bent rims. (and I've reused the spokes on each new wheel...not recommended but they've worked fine so far).
Keeping in mind my trike abuses the wheels a lot more than a typical bike, almost anyone would be find with thinner spokes 14-15g butted, and have a much better tougher wheel.
But anyway, the thicker spokes are generally the main cause of the problems described in this thread so far. (because they can't be tensioned sufficiently without damaging the rim, which then lets them loosen...).
Interesting, I haven't used it yet but they did seem very loose. My normal wheels have 14g spokes and you can play them like a harp almost. The hub motor uses 12g and they you can easily bend them with your fingers.
Apparently they use a 14g rim, whatever that means. I think they are referring to the thickness of the aluminium used when pressing out the rim? The supplier said they get the rims specially made for their hub kits. Supplier is Pasion eBike.
Apparently they use a 14g rim, whatever that means. I think they are referring to the thickness of the aluminium used when pressing out the rim? The supplier said they get the rims specially made for their hub kits. Supplier is Pasion eBike.
I haven't seen rims listed by gauge, so I don't know what that means.
Most likely it means it's made for 14g spokes, maximum, meaning that like most hubmotor wheels, it's built with way too thick a spoke for the rim, so it'll damage the rim when you tension teh spokes, which detensions the spokes. Essentially makes it impossible to properly tension the wheel.
It's unlikely they get the rims or anythign else they sell made for them specifically, they almost certainly do what almost everyone else does--buy in bulk from whoever is cheapest at the time, and slap a sticker on it for their brand name (if even that).
The rim may not simply fail, but cracks will occur around the nipple holes, and as the aluminum bends there,spreading around the hole, the nipple pulls thru a tiny bit and loosens the spoke. If you retension it, the cracks get worse, to where you may be able to see them, and spread, and the nipple pulls thru again, again loosening the spoke. If you *don't* tension them, then eventually the nipples may unscrew from the spokes from the repeated loading/unloading as the wheel spins, or the spokes may break at the J-bend by the hub.
Can be immediate, or take months. Depends on rim, spokes, nipples, weight, road quality, tire pressure, tire volume, and various other things.
Better to just build the wheel with the right spokes to start with, which for most bicycle rims is 14g or smaller. (bigger numbers are smaller spokes).
Most likely it means it's made for 14g spokes, maximum, meaning that like most hubmotor wheels, it's built with way too thick a spoke for the rim, so it'll damage the rim when you tension teh spokes, which detensions the spokes. Essentially makes it impossible to properly tension the wheel.
It's unlikely they get the rims or anythign else they sell made for them specifically, they almost certainly do what almost everyone else does--buy in bulk from whoever is cheapest at the time, and slap a sticker on it for their brand name (if even that).
The rim may not simply fail, but cracks will occur around the nipple holes, and as the aluminum bends there,spreading around the hole, the nipple pulls thru a tiny bit and loosens the spoke. If you retension it, the cracks get worse, to where you may be able to see them, and spread, and the nipple pulls thru again, again loosening the spoke. If you *don't* tension them, then eventually the nipples may unscrew from the spokes from the repeated loading/unloading as the wheel spins, or the spokes may break at the J-bend by the hub.
Can be immediate, or take months. Depends on rim, spokes, nipples, weight, road quality, tire pressure, tire volume, and various other things.
Better to just build the wheel with the right spokes to start with, which for most bicycle rims is 14g or smaller. (bigger numbers are smaller spokes).
If I was more confident with bikes I would attempt that but for my first ebike I wanted to cut some corners so ordered a complete wheel.
I think I will tighten them bit so they are at least all even and just inspect it regularly. When I can see some signs of wear/damage I will look into building the motor into a new rim with normal spokes.
I think I will tighten them bit so they are at least all even and just inspect it regularly. When I can see some signs of wear/damage I will look into building the motor into a new rim with normal spokes.
markz
100 TW
I have a motorcycle rim that would use 12G spokes, but I havent found any 13 or 14G at the J bend (for the bicycle hub) and 12G at the threads, so nipple washers are an option, and remember they add a little bit to the ERD of the rim.
For motors with large J-bend holes like the MXUS 3kw of mine, I have used washers.
For motors with large J-bend holes like the MXUS 3kw of mine, I have used washers.
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