They are alu rims with carbon fairing bringing them t0 60mm. Hed says their clincher rims are all designed with 23mm wide tyres which is why I ask. I want to stick a 25 on the back
On the rear, it's far less of an issue. Do it.
some test data for zipp 303 and 404 with 23 vs 25 tires:
@Hovis started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
They are alu rims with carbon fairing bringing them t0 60mm. Hed says their clincher rims are all designed with 23mm wide tyres which is why I ask. I want to stick a 25 on the back