Originally Posted by
jaxgtr
[COLOR=Blue]Actually, your tires are 700c x 35. Your wheels have a different designation based on how wide the rims are. Yours are probably 20mm to 24mm wide, meaning you probably have a reference of 622x20 or something like that. Basically 622 = 700c and the 20 is the rim width. If you don't see a marking, measure the rim inside the rim walls. The width of the rims will give you a basic idea of the limits on tire size you can use. I narrower tire would be easier to use on a 622 x 19 than say a 622 x 24, and wider tires of 38mm would be harder to fit on a 17mm width. Even though you might be able to mount them, safety would be a concern.
See this from Sheldon's site.
Sheldon's numbers are conservative. I certainly wouldn't go with a wider rim and a narrow tire, however, very wide tires can be used on very narrow rims...with some caveats.
Mountain bikes regularly run tires that fall way outside of the numbers provided by Sheldon. For example, a Mavic XC717 rim is 17mm wide and you can easily run a 2.3" tire on one. That's a 58mm width. However those are high volume and low pressure tires. Most tires that wide are only rated to 60psi. But then most 32mm+ tires are rated to relatively low pressures too.
Originally Posted by
jaxgtr
2. does the 35c determine the maximum width of my tires?
Yes, 35 is the width in mm.
I would only add for clarification, that 35mm is the maximun overall width of your current tire. It is not the maximum wide tire you could use.