Geared hub motor sticky freehub when axle is loaded

Hey guys,

sadly this is not just a disasseble-clean-grease-reassemble problem because my motor is new and has not seen any dirt or water yet. I have the XF19C version of mxus's most powerful geared rear hub motor series.
The problem is that as soon as the motor axle is loaded (for example if I sit on my bike) the freehub becomes quite hard to turn. I can still ride my bike that way but the cassette spins so badly that while im riding the upper part of the chain loses tension and drops below the chainstay. When the motor axle is unloaded the freehub spins ok.
I have already tried to tighten the lockring of the freehub body which helped but did not solve the problem (chain still drops). If I remove the bearing which sits above to the freehub lockring (see picture) the problem disappears, but I am not sure if the axle is strong enough to handle the extra stress without the support of that bearing.

Do you have any ideas how this problem can be solved?
Thanks a lot in advance!

Very hard to tell without a picture of the bearing stuff but it is surely there for a reason. Maybe put some cassette spacer behind the cassette so it doesn't touch?

whoops, thanks for the reference, I didn't realize that the attachment did not work. Now as a pdf it works, does it help?

Hey guys,

I found the solution to the problem. After a bit of trial and error I realized that if I don´t hammer the outer bearing in the freehub completely but leave a tiny gap between lockring and bearing the problem disappears. I am confident that this is actually the way its supposed to be and that it will not make any problems any time soon.
I hope this thread will help anyone with similar problems in the future.

chris09...where did you buy your MXUS XF19 motor?

I was looking on the MXUS web site and I couldn't find it.

Thanks

Bullfrog said:

chris09...where did you buy your MXUS XF19 motor?

I was looking on the MXUS web site and I couldn't find it.

Thanks

Click to expand...

Aliexpress, chamrider

Thanks...I did a little research and the XF19C is a 10 pole motor where the MAC is a 16 pole.

That alone doesn't mean anything besides the MAC may have better torque and the MXUS may turn with fewer losses but the MXUS also has a 5.8:1 reduction where the MAC has a 5:1 so in the big picture they are probably pretty equivalent.