This question already has an answer here:
what size tire can install on my bike? I have hybrid bike (gary fisher Tiburon 2006). It has 700x35C tires on it or if you want to call it 37x622. I want to install the widest tire possible to ride on semi rough trail. Today I received my new tires 700x42c but I wasn't impressed with the unnoticeable added width of 7mm as if there is no difference in size.
I have lots of clearance on all the relevant tires and frame to accommodate wider tires. I have about 3/4" on both sides of the front forks and rear frame. Also enough space between the brakes holder and rim. I checked with a bike shop and they advised me that I have enough room for much wider tires.
Please advise the widest tire size I can install on my wheels.