Hi all.

I'm in the market for some new wheels and with the trend for wider being better I'm doing some research.
I have a cannondale supersix evo 2015 which has really narrow chainstays at the back. I have 25mm conti gp4000s (actually measuring just over 26 with a verneir) on a 22.4mm (rs81 c24 rim). I have had no issues with about 3mm of clearance either side and about 3000 miles miles including a mountain trip on the frame.

If i went to a 25mm rim with a 25mm tyre would the tyre come up wider than the 26mm I'm measuring at the moment?


velochris [17 posts] 8 months ago

It is the rims internal width that matters as thus dictates how much the tyre will "balloon".

For reference I had a h plus archetype 170mm internal. A 25mm Schwalbe measures 26mm with a vernier.

Same tyre on Kinlin xr22t 19mm internal is 27.6mm.

Finally, a 25mm GP4000 on Pacent Forza 20mm internal rim is 27.85mm.

Hope that helps

HalfWheeler [667 posts] 8 months ago