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.

  • The specific "exactly which tyre should I buy" can't be answered because it depends on how much clearance you want, minor variations between tyres and wheels and frames, and what you mean by "trail". Why not ask the bike shop, since they can simply try different tyres and sell you the widest one that actually works on your bike. They will charge for that, but it should be significantly less than the cost of buying an extra tyre. That difficulty is likely why the :LBS didn't tell you an exact size either.
    – Móż
    Sep 17, 2016 at 2:52

1 Answer 1


If you have a 42mm tyre, and still have 3/4" of clearance at all possible points, then your maximum size would be 42mm +19mm = 61mm.

Do check the clearance at the chainstays, the seat stays, and the brake bridge. You imply you have rim brakes, they're often the limiting factor.

  • 1
    Also check the front derailleur clearance while it is on the smallest chainring.
    – mikes
    Sep 17, 2016 at 1:29
  • thank you for the help. I think it is best to take it to a bike shop to make sure of the clearances.
    – user29360
    Sep 17, 2016 at 1:33
  • 1
    You do have another limitation: rim width. Technically, any 700c tire should mount on a 700c rim. But, you don't want a super wide tire on a narrow rim and vice versa.
    – Batman
    Sep 17, 2016 at 2:20

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