I have a trek 3500 and I want to make some modifications for city commuting. I have done nothing to this bike since I have had it, so I assume all the components are standard....21 speed shimano, aluminum frame..etc. There are Bontrager Trail tires on it now. Does anyone have any suggestions on better city commuting tires and anything else that would make my ride to and from work more enjoyable. Any help would be great as I am purely a begginer in the world of biking.