So, I have a Trek 7.2 FX with 700x35 tires. How would I know how skinny a tire would still fit on my rims? Are there advantages/disadvantages to going skinnier... or staying wider? I don't ride off-road at all but the roads I ride on can be pretty rough and I ride on a tow path along the river a lot - some parts of it are good and some..not so good. I'd love any information anyone has to offer!

pat