LOL!!! The area I live in is very, very hilly. It seems that I am either going up or down, no flats. When riding my geared road bike and testing to see what gear will work best for me for a single speed, I seem to need a 42 x 21 to climb these hills and if I went one gear higher I would probably have troubles. I also don't want to introduce any knee pain. The thing with that gearing is that on the little flats that we do have I seem to be spinning like crazy. Perhaps I should just except the smaller gear and work on my spin for the flats? Is a lower gear higher rpm better on the knees that a larger gear with lower rpm? Again, I feel that a fixed would cause me problems on the downhills because of the smaller gearing. I don't think that I would be able to maintain a 160+ leg rpm Thanks for all the advice.