I have a 7 speed Hyperglide with 30-26-23-20-17-15-13. I'd like to drop the 15, and 13, and put in a 21 and 18.
That would make it 30-26-23-21-20-18-17. How would I go about doing that? I found on nashbar this http://www.nashbar.com/profile.cfm?c...A%20Freewheels
It is a 7sp with 13-32, it comes with a 21 and 18 that I could use as donor gears to my cassette?