Will 28c tires fit in my 25c rated frame? I have measurements

[cheapvega]

I have an open mold rim brake FM098 that has a 25c rated max clearance. The minimum distance I measured between the frame/fork/brakes and the rim is 31mm (the GP4000 23cs on the bike have a 22mm height and there is 9mm of clearance). I would like to get the 28c GP5000s which measure 26mm tall on a 17c rim. I plan to put them on 18.5c rims (28mm wide vs the 23mm wide currently on my bike). Is 4-5mm of clearance enough? Will I gain a little more clearance with a wider wheel?

[rcrowley]

Typically folks recommend around 4mm of clearance on all sides of road tires (with Rene Herse going down to 3mm). The lower you go, the more you have to keep on top of your wheels' true.

[bobones]

The tightest point on my bikes is usually under the caliper, but I get away with 2-3 mm clearance without rubbing even in wet, gritty conditions. In theory, a tyre should be less tall on a wider rim so, yes, potentially more clearance there.

[Ypuh]

The tightest point differs per bike.

I would stick to a minimum of 3mm on each side, which might already cause rubbing with flexing wheels and/or out of the saddle. For example the small rubber hairs on brand new tyres will already cause you issues at 3mm so you'll want to cut those off first.

Other than that I experience few issues, except in France with boiling asphalt patches which sticks debris to your tyres and again damages the paint.

[cheapvega]

I am a super fair weather rider and the roads here are decent. I'm going to get the combo and see what happens.

I did notice the 23cs are actually pretty supple and are so much faster than the Tufos. So absolute worst comes to worst I can just go down to the 25c. But I'm hoping the 28s will fit.

[TobinHatesYou]

The ISO minimum is 4mm to any part of the tire. I can't see 3mm being much of an issue since 1mm of run-out is within expectation. <3mm is real iffy.

[cheapvega]

Great news. Mounted the tires on new wheels today. They are wider (27.2 tire on 28.4 rim) but pretty much the same height as my other tires at recommended pressures. So diameter clearance is basically the same. Can't wait to go for a ride!

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