Does anyone have any experience with changing the gears on an old freewheel cassette? My old back wheel had the new style cassette with a range of 11 - 34. When I changed to the HD Freewheel hub, I had to change to an old-style 7-speed freewheel cassette. The best I could find is 13 - 34. I miss my old 11. I'd like to switch an 11 (or smaller if it's possible), for the 13 I have. I read Sheldon Brown's article on it, and he says it's doable, and I think I could handle it, but... Are there any tricks? And where do I find an 11t gear. I can look through the parts pile. Perhaps I can find an 11 on a road bike in there. I'd appreciate any advice.