Hmm... I don't ride my other bikes that much anymore. I just don't get the same input from them. My ss mtb which is running 47x16 doesn't have the snap my track bike does. Of course the heavy rhynolite wheel doesn't help too much, either, but that mtb's gotten my friend all ready for his foray into fixed gear bikes. If you're geared properly and know your limits in order to ward off injury, I don't see there being a limit in how far you can ride a fixed. Get a comfortable saddle and a bar that allows your hands to get into different positions and you should be all set.