>>2057134

I mean, just measure it (trace the size of the canti post onto paper, or use calipers) and go to the hardware store. Unless yours is really shit they should have a fuck ton of washers odds are one will work.

If that fails, buy one that fits inside the cantilever arm, then drill out the inner diameter to be the right size

Would be wise to clamp the washer down/hold it in a vice