Torque arm

[Andy1865]

Do shop bought ebikes that NOT conversions that have over 500watt rear hub motors have built in torque arms or do they still need torque arms even if they have steel dropouts?
Thanks.

 

[JRA]

Should have a torque arm on any hub motor front or rear just to be safe. Steel dropouts and the funky tab washers just aren't enough.

 

[rich c]

They all need them, but some shop bought can still be cheap generic Chinese bikes.

 

[SpanishFlyer]

My GUNAI ShengMilo MX02S came with a sort of torque steel plate on one side, But I was wrong in thinking that that was enough, even after I had swapped the 750W motor for a 1.500W, but I was very wrong... Thanks to the almost sudden squeaky rear brake, after a 37km run, as I arrived home and removed the pads, I knew something else was happening. The pads were worn only on one part of the surface, leaving a clear groove down the middle of the pad. Checked the spindle lock nuts and I found both side to be tight enough, but since I hadn't changed anything on the caliper or support plate, it could only be one thing, the spindle partially falling down the dropout slots.
After removing both spindle nuts I found that if I had ridden the bike a bit longer or hadn't hear the brakes complaining, the motor would have eventually turned around with the wheel and probably letting the wheel come off with a more than certain accident.
I have now ordered a new set of pads and a proper set of torque arms, yes, two, one for each side of the wheel. I attach some photos that explain better than me what almost happened.

 

[tomjasz]

eBikes.ca has sweet torque arms. Not stamped Chinesium.

 

[SpanishFlyer]

Thanks a lot tomjasz will take a look and find out if I can get them in Europe.
Best regards,
SpanishFlyer