Will a hub motor fit thru axle fork?
- Thread starter Mati5300
- Start date
Bigwheel
1 kW
Other than the grin product, which is excellent btw, not possible.
Chalo
100 TW
Mati5300 said:
I have a thru axle fork that's over 20 years old, which has pillow block style end caps. It could be fitted with spacers in the fork ends and flat plates in place of the original pillow blocks. This isn't my fork, but the tips are similar to the one I have:
If the fork tips of your fork open up enough to drop the axle out the bottom, then you could make 20mm diameter spacers with holes through the middle to fit your axle. As long as they're able to clamp down on the axle, or else bonded strongly to the axle with high strength adhesive, then you could clamp the hub into the fork tips. If the clamping is strong enough to keep the axle from spinning, then you're all set.
If any one of the above conditions isn't true, it won't work.
LewTwo
1 MW
Hard to tel from that picture but I would bet that the bottom end is something like one of these.
My thought is "Do not do it".
My thought is "Do not do it".
Zynode
1 µW
- Joined
- Mar 13, 2021
- Messages
- 4
In my experience suspension forks and front hub motors don't match together because of aluminum/magnesium material. It will shear instead of yield like steel. I would guess that it is possible at 250-500W with 2 torque arms, no regen (unless perfect no play custom torque arms i suppose) and checking nut tightness often. Though i have no experience in that power level so asking other members is a better idea.
I sheared my rockshox's because i'm a dumbass. 1kW ~7kg hub motor, 2 torque arms but only good 1 direction, regen and i did check nut tightness every other day. Just didn't check one time and sheared my forks. According to Justin's interesting [fork shearing experiment - https://endless-sphere.com/forums/viewtopic.php?f=2&t=14195 the forks can take only so much torque. So a small geared motor can perhaps have the same starting torque or exceed that compared to a heavy DD hub motor (i think mine had ~60Nm). Limiting in the controller starting ramp up amps in KT controller helps lowering starting torque. Also helps not checking chinesium spokes unwinding as often. Either way should have relaced it with proper spokes and quality rim from the start.
Also in my experience the heavy 7 kg hub motor locked in the suspension by quite a bit. ~2-3 kg geared hub motor of course is a much better idea. For me it only worked on big curbs/potholes and only in disappointing levels of cushioning. Just went CrMo steel rigid fork for 100 euros and it's a tank. No regen this time to test reliability. Maybe in the future.
I sheared my rockshox's because i'm a dumbass. 1kW ~7kg hub motor, 2 torque arms but only good 1 direction, regen and i did check nut tightness every other day. Just didn't check one time and sheared my forks. According to Justin's interesting [fork shearing experiment - https://endless-sphere.com/forums/viewtopic.php?f=2&t=14195 the forks can take only so much torque. So a small geared motor can perhaps have the same starting torque or exceed that compared to a heavy DD hub motor (i think mine had ~60Nm). Limiting in the controller starting ramp up amps in KT controller helps lowering starting torque. Also helps not checking chinesium spokes unwinding as often. Either way should have relaced it with proper spokes and quality rim from the start.
Also in my experience the heavy 7 kg hub motor locked in the suspension by quite a bit. ~2-3 kg geared hub motor of course is a much better idea. For me it only worked on big curbs/potholes and only in disappointing levels of cushioning. Just went CrMo steel rigid fork for 100 euros and it's a tank. No regen this time to test reliability. Maybe in the future.
