Width of 23mm Tires on 25mm (External Width) Wheels

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by jacklafleur

I'm one of those frustrated souls dealing with wheel rub on the chainstays of my Cannondale SSE Hi Mod any time I use a tire over 23mm. I'd like to transition to an aero wheel and I'm wondering what measurements any of you are getting on your 23mm tires when mounted on 25mm External Width Wheels.

I have 30.6mm between chainstays and my current GP4000s measure 24.8mm @ 90psi. This presents no issues with clearance...but it's a box rim and poopy.

I'm wondering:

What 23mm tire are you using?
What 25mm wheel are you using?
How deep is your rim?
What width do your 23mm tires measure on your 25mm wheels?

Thanks so much for your help!

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by rheosibal

What year is your Evo? Also, internal width is more important to consider vs external when determining how wide your tires will stretch out to.

I've had no problems fitting a 28c tire on my 2013 evo, and a 30c on my 2018 evo. Each on 19.5mm and 21.5mm internal width rims.
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by Alumen

That are tricky questions. Regarding the tires, it varies per brand as well on how they meaure.

On my box / winter wheels (Mavic Aksium, 25mm, internal 22C rear and 19C front), I have noticed that the 25mm Conti GP4000s measured definitely more. But Schwalbe (Durano) and Vittoria (Rubino Pro) meaured quite close to the rim size. Also the Rubino Pro's now on my Fulcrum Quattro's (17C) are nicely fitting close to the rim size (and the Fulcrum rim is just over 23mm).

I think you would be pretty safe with Vittoria tires, they don't balloon as much as the Conti's. Even Schwalbe's are ballooning more than Vittoria's.
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by bilwit

(all clinchers)

23mm Continental GP4000SII on 17.9mm internal/25mm external measures 24.75mm new
23mm Vittoria Corsa on 18.35mm internal/25mm external measures 25.4mm (~700kms on them)
26mm Compass Cayuse on 17.9mm internal/25mm external measures 25.5mm new

they will balloon about 1mm wider once they get worn in

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by alcatraz

You are running a tire over 23mm if you are currrently at 24.8mm.

Don't be so obsessed over the number on the tire. You are getting 24.8mm of comfort and rr.

When going wider rim you will unlikely have room to up the tire size (as written on the tire) because the internal width will enlarge the already near limit 23c tire to over 24.8mm.

Vittoria tires are very narrow. My 25c measures 24.5mm on a 23mm ext wide rim. Does that mean I'm enjoying 25c comfort and rr? Hell no... :lol:

Decide what your max width for the frame is, and aim for that. 25mm or 26mm? For every mm of internal rim width increase the tire will too increase.

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