Golden Motor freewheel problem

[billvon]

So I hooked up a Golden Motor 1000W 48V this weekend to try it out. Under power it seemed to work OK. Then I pedaled a few revolutions. Then I stopped. The chain kept going, trying to drive the cranks. When I forced the cranks to stop, the chain spilled over the top of the rear cluster onto the derailer and everything jammed solid.

I tried it again on the bench. When the freewheel bearing lockring is torqued correctly, all is well. When I apply torque to the cluster, the freewheel tightens against its own bearings and locks up. At that point the cluster is locked to the wheel, and no freewheeling is possible.

Anyone else have this problem? Regular freewheel tools don't work (of course.) I can get the entire assembly off the wheel by taking the lockring off the cluster and taking the entire freewheel off, but then ball bearings spill everywhere and it doesn't fix anything anyway.

 

[Ypedal]

There should be a spacer behind the freewheel ( goes over the threaded collar before the freewheel gets threaded on the hub.. )

this prevents the freewhel from threading itself too far onto the hub causing what you describe.

If you ream/drill out the centre of a freewheel tool it will slip over the axle and allow you to remove the freewheel from the hub.( No fun.. been there done that.. )

 

[philf]

I believe the final machining of many of the parts in the GM motor (or virtually ALL of the Chinese hub motors, for that matter) is largely done by hand. There are a lot of small inconsistencies from unit to unit.

I have three GM rear wheel units, and only ONE of them has a cover that binds against the freewheel. I didn't want to add a spacer to this unit, so I carefully ground off the excess shoulder on the aluminum (less than 1/32") with a Dremel and a grinding wheel. It's perfect now...

As for getting the cluster off... You'll have noticed that most Shimano freewheel tools won't slip over the oversized axles on hub motors. I enlarged the hole on mine, and it works fine. VERY well hardened steel tool, but 10 minutes with the aforementioned Dremel/grinder combination had the hole the right size and perfectly round.

Cheers!

 

[biohazardman]

I had the same problem when I changed out the freewheel on my Schwinn a few days back. I fixed mine much the same way as Philf. While spinning the wheel by hand I held a Dremel to the offending oversized, for my Shimano, piece of casting on the wheel. Took more than 1/32 of an inch off, both in width and height, but no matter all is well now.
I also had to modify the freewheel remover tool as he did. Arm is still pretty weak so used a 1/2 inch airgun on the tool and the freewheel did not even try to resist but spun right off. Even left the threads on the wheel how lucky can you get? ;^)

 

[set]

ypedal is right, there is suppose to be a silver-ish spacer that goes between the threaded axle and frame. As for true freewheel, I don not believe GM kits have them allowing them to regen. I couldn't find this "spacer" for a good 2 hours after I got my kit. Then I realized it was not a "shim" and it was inside the thumb throttle opening! Hope this helps.