jamesridingbici

Hi, I am looking to fit new wider tyres to my bike with ultegra 6600 and cant see online much info on max tyre clearance. There are 23mm tyres on it at the moment, and i think i could get 25mm but would love to get 28's. What do you think? I know the chain stays can be a limiting factor, but i think the clearance there is fine. Thanks for any advice

Iride01 

Find the location on your bike that comes the closest to your tires. Both for the treads outer diameter and the sidewalls. Rear tire it usually is the seat tube for the tread, but maybe the center of the brake calipers for rim brakes. And of course it's usually the chain stays for the sidewalls. Front wheel will be the width of the forks near the crown and the brake if it's rim brakes.

Tire diameter increases about the same as the width. So a 23 going to a 28 will be 2.5mm added to each side of the sidewall and 2.5 added to the tread. But realize that tire sizes aren't absolute. And a 23 of one brand or even model of tire might not really measure 23. And if you get a different brand and model of tire it's even more of a crap shoot. So leave yourself a good margin. Or just be willing to pony up for a smaller size if you get too big.

Welcome to BF.

delbiker1 

I am using 6600 calipers on a LeMond Tourmalet. Depending on the rims, some 28mm tires will barely slip through the pads when the calipers
are opened. With wider rims, when the tire bulges, I have to let air out to clear. For me, with tubed clinchers, that is simply not an issue.

jamesridingbici

Thank you very much for the suggestions, very kind! Will try some 25s

jamesridingbici

Thank you for sharing your experience, very kind

BTinNYC 

If your frame can tolerate wider tires, maybe a different set of brakes. Tektro 539s fit a 32mm tire and are about $35 on the auction site.

delbiker1 

This is a good suggestion, they work well.

biker128pedal

I had a Madone frame with 6600 brakes. 25mm Conti 5000s blow up to about 27mm and were too close to the fork bridge but plenty of clearance to the brakes and fit through the pads. 25mm fit in the rear. 28mm Conti 5000s blow up to about 29mm and fit but were really too tall for the frame in the rear. They would have cleared the brakes. Fitting though the pads was tight. In some ways I was lucky and the frame broke. Trek warrantied it so I upgraded to a Domane SL6 which easily fits 38mm wide gravel tires.

Oh this was on 19mm inside width Aeolus Pro 5 wheels.

bblair

For me, the critical measurement is the space between the front tire and bottom of the fork crown. If I run anything larger than 23mm (as listed), then leaves and small pebbles get stuck. Laterally, plenty of room.

So check all sides.

rm -rf

my old road bike had very tight clearance under the fork. It was fine on dry roads, but when I rode through some damp rough sand scattered on the road, I could hear the "zing" as the sand adhering to the tire went through the fork area. Scratches in the paint. That was an ongoing problem that I didn't like.

I use hex L wrenches to check for clearance spacing, both at the tread of the tire and along the sidewalls. It's the distance across the flat sides of the wrench, of course. I usually want at least 4 mm of clearance, and more is helpful for handling tire variations, debris on the road, etc.

SpedFast

Although it's tight in the chain stays with 28's and I have to put the wheels on with the tire practically deflated, my tightest issue is the front derailleur when I'm on the big chain ring. I have to feather the front DR and only use it all the way over when I'm in the last (smallest) cogs. It clears, but barely. My front DR is a 105 from the 5800 group and where the cable connects is what moves toward the tire as I upshift. Just another thing to watch for when upsizing tires.

mstateglfr 

I am hoping the board can tell me what the color red sounds like.

SpedFast

Are you sure you really want to know?

Jughed

I can fit fully inflated 28's mounted to my stock wheels thru my 6500 calipers.

Trakhak