I have an oldish Giant Attraction mountain bike with Kenda 26x1.95 knobby tires. Since I haven't left the pavement in years, I've decided that it's time to swap them out for some skinnier slick road tires. Will 26x1.5" tires fit on my rims? 26x1.25"? My bike budget is pretty near zero right now, so buying new wheels isn't really an option.