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?