runaway_pancake:
Anybody know of a sprocket source?
Looking for #40 roller chain (bicycle) sprockets with an 11mm bore (keyed).
I need more than 9-11 teeth, more like 20.
There is a standard size of chain out there that matches bicycle chain in pitch, but is wider than bike chain (I don't recall specifics - I'll try to look it up tonight when I get home); you can easily find such sprockets to match this chain (as it is an industrial and standard spec size). What you do is purchase such a sprocket to the spec you need, then you take it to a machine shop (with a bit of your bicycle chain), and have the shop face-grind/mill the surface of the sprocket to the proper thickness (they should also re-chamfer the sprocket teeth so the chain will ride properly). This won't be cheap for a single sprocket (depending on the shop, of course), but it likely will be your only real option (short of having a custom sprocket made - which will probably cost even more than doing the above).