I was ridding a 700c35mm tires with a 34x14(66.0) which was great for the C&O Canal, and I was able to do a normal route, but a little slow for Washington DC, and anything pruely flat. I went to a 38x15(68.8) and I like the speed of the gear, but it was not working on a normal route that included some up hills, so I am torn about what to ride, I can go with the 38x15 (I road to work today) and pick special routes that are flat, or the 34x14 and have more choices but a little slower. I am thinkning slower, cause if I want speed I have other bikes.