2 broken front suspension forks

[Punx0r]

1.027 Nm/A? 100A peak phase current for a Cro-motor? I think there are a few people on here that treble or quadruple that...

There is no way a major manufacturer of good quality frames is going to redesign their product range to fit after market hubmotors from small manufacturers in China or Eastern Europe. That's just not realistic.

A key on the shaft might be workable, then people would need a broaching tool to cut a key way into their dropouts. That torque at a 10mm radius might prove too much, though.

Or just have a 20mm shaft with 20mm flats on it and people can bolt clamping torque plates onto their dropouts as before.

 

[amberwolf]

...it should be easy for Cromotor with their own frame , but they need to ensure independent motor buyers can use other frames also.

Remember that Cromotor (and other high-power motors like Hubmonster, etc) was basically adapted from a moped/scooter motor, not a bicycle motor.... So adapting it down to a bicycle's limitations also means adapting its power handling capabililtes (regarding torque at the axle itself) down, which makes it kinda pointless for many of the people that want it for that higher power/torque.

The adaptation that needs to happen (to use these for bicycle frames, not designed for these torque levels) with all of these higher power motors is to make them like the Heinzmann motors, with a torque arm built into the motor itself, with the axle section between teh dropouts being *much* larger diameter than most presently are, to support that arm (at least one, but preferably one on each side), and then just a plain hardened 10mm *round* threaded axle for the rest of it's length thru and past the dropouts, because the flats arent' needed and just weaken the axle especially where it joins the shoulder to the rest of the motor axle, and weaken the threads' ability to carry the loading from the nut and keep the wheel on. (though that would be almost irrelevant if it had built in torque arms on each side).

Then these motors could also be easily enough used with 20mm dropouts, too, just by adding a slip on or thread on cylindrical adapter sleeve over the 10mm axle.

If there are no axle flats, then there is also nothing limiting what angle the built-in torque arm is at relative to the dropouts, so it can be rotated around to whatever position fits the fork or stays best. Adapter plates can easily be made to get those arms to mate fully with the fork or stay shape, too.

 

[BiciMad]

I had everything installed ( new steel rigid fork, suspension seatpost, marathon plus tour front tyres, and marathon plus rear ). Battery it's a 36 13ah, fitted temporally on the back. The motor it's a Mxus 350w 36v & 15A controller. I've still gotta give it a proper test, today i came late, and i just could make like 3 miles, enjoying the lack of bumping from the suspension so far, and also the Xlc seatpost, but it feel it moves side to side a bit, kinda weird, but not much problem.

The new fork with the torque arm looks like this:

And the whole fork:

And the ebike:

Btw, if the ebike looks ugly, good, i've gotta make it uglier. The less attractive it's the better. I've got to stain the frame, hide brand, and lock better rear wheel, batteries and controller. The weird thing you see hanging from the seat, it's a bicycle chain, locking frame & seat post & seat, and lightly the controller and the battery.

 

[BiciMad]

Well i could finally could test the new steel fork, the battery and suspension post, and ther results are optimal.

Yesterday i rode like 125kms, it's the longest i've ever rode (some might giggle, i know, i´m just starting...). I took a fairly bumpy and rocky road. I did everything could to put preasure on the front frok, and nothing happened .

The battery, 36v 13ah (50 ICR18650-2600F) seems to have more power than i expected, altough i pedal a lot, i think i can make 130-150 kms out of it, because i rode 125 yestarday, and still got 2 battery bars.

I kinda like the seatpost, it gives some mild suspension and it's not uncomfortable to ride, highly recommended.

I'm planning on doing 650 kms through country roads ( Camino de Santiago ) and that would be the final test for this e-bike configuration, looking forward it...