Originally Posted by kingston

I agree that you need to try out a few and see what works, but I have been riding fixed for a while, have a bunch of different gears, and sill use the calculators. Yesterday I went for a little 25 mile ride, and my top speed was just over 31 mph. I was spinning like crazy, so I thought about changing to a higher gear when I got home. I used the bikecalc cadence at speed calculator to determine that I was spinning at over 150 rpm at my top speed, which is about my limit. My average speed for the ride was a little over 19 mph, which means I spent most of my time on the flats in the 20-21 range, which is a cadence of around 100 rpm. If I add two teeth on the chainring it drops it down ~5 rpm or I could drop a tooth on the sprocket to bring the rpm down by ~7, but then I'd have to shorten the chain, so a bigger chainring seems like the way to go. I guess I could have just started swapping parts, but it's nice to have some idea of what's going to happen before I make any changes.