My dad and I had to take off the back wheel of my bike and ended up with everything in place except for this washer-looking thing (on the other side of the wheel). I’ve been trying to use image searching to find what it might be called specifically so we can try to find/buy a new one but I haven’t had any luck
by genericlabassistant
5 Comments
anti-rotation washer?
[https://www.amazon.com/Electric-Anti-Rotation-Washers-Components-Accessories/dp/B0DSBDLG5C?th=1](https://www.amazon.com/Electric-Anti-Rotation-Washers-Components-Accessories/dp/B0DSBDLG5C?th=1)
That is a non-spin washer. It’s keyed to the axle and stops the axle from spinning in the dropout from the motor’s activation. Without it, the wheel could spin itself out of the dropouts.
It’s an anti-rotation tab or washer. The washer part is shaped to the axle, it can’t rotate because flats on the washer mate with flats on the axle. The bent part locks into the dropout on the frame to prevent the wheel axle rotating under the force of the drum brake. If that were to happen, the brake would be ineffective.
The washer probably came as part of the drum brake assembly, so you would need to get the brake make and model and look for stockists. A shop that sells and repairs drum brakes may have this item as spares.
Others have answered what it is (Shimano calls them non-turn washers), but understand that there are several designs to accommodate different dropout configurations (the tabs that accept the axle). Yours is a horizontal dropout. The tabs are also specific to the hub brand.
They are a pain in the ass to get off that is what they are.