Power Adders
Kenne Bell 6 Rib Steel Pulleys for 12mm small drive hubs. One is a 2.5", one is a 2.62" (measured with digital dial calipers). Fits the 1.7/2.2's with the 12mm drive according to Kenne Bell, also fits the 2.1/2.6/2.8 2v and 3v setups. Not sure what all else they fit. $35 shipped each