FrenchFit 

Put a 700x28 rear tire on my Bianchi road bike, clears the brake bridge on tire top by 6 laminated business cards, about 2.5mm, at full pressure. Plenty of room on the sides. Is there are rule of thumb on how close you should go? On the front I'd be nervous, the back not so much...

caloso

If it clears, it clears.

ThermionicScott 

Pretty sure my Eros has about that much clearance. I used to have less when I had 700x30 pseudo-cyclocross tires on it.

Lemond1985

I run my tire clearance close. Where I draw the line is if there is a lot of debris being scraped off the tire and ending up on my brake calipers. If you think about how a wheel turns before it passes under the brake bridge or fork crown, something would have to be very securely embedded in the tire to stay on, like a nail, screw, or thorn, to ever hit that caliper. A loose rock or twig will fly off long before it reaches that far.

I had not had any problems on pavement, but if you ride on dirt or gravel, you'll probably end up scraping lots of debris off both tires. But I can't see a catastrophic event ever happening. Certainly anything is possible, but I've got bigger worries. Like squirrels trying to jump through my spokes.

rumrunn6

do you have to wait on inflating until after the wheel is mounted up in the drop outs?

these tires fit if I do that

FrenchFit 

Thanks all ; did 2 hours on the road and some gravel, nothing new.

ThermionicScott 

Just pumped up the 700x28C tires and measured the clearance: 2mm in back, 2.5mm in front. Here's to cheating death, @FrenchFit!

FrenchFit 

due ruote 

I would be much more concerned about stay clearance than crown or bridge. Ideally if you break a spoke you still want to get home.

pdlamb

I'd be leery of that little clearance if I took it on gravel, since gravel around here tends to also be muddy. Gravel sticks to mud sticks to tire and instead of riding you're at the side of the road trying to scrape a quarter inch of gook off the tire.

But since you've tried it and it worked, carry on!

BCDrums

Y'all are more daring (or less chicken) than I. I put some new 700x32's on my wheels. The flashing at the center of the tread was just tickling the brakes. It would have worn off fairly quickly, but I wasn't comfortable with that. If something got stuck to a tire and jammed at the brake it might stop the bike dead. I got some 650b's and am now running 38s. That's an extreme solution, but I love the wider tires.

ronin4740

I took a dremel with a drum sander bit on it to the bottom of the rear triangle to create a bit more clearance on a Fuji Roubaix I own as the 28mm tire was just barely rubbing as one part of the wheel went through that area.

Left plenty of aluminum there for support when I was done. All seems well after a few rides. Wouldn't recommend this as a general fix but it worked in my case.

Brocephus

I have a '14 Fuji Roubaix 1.3, and am running some Continental 32's, with no issues. It's pretty close, obviously, but not dangerously so, I don't believe. What model and year is your bike ?

ronin4740

Mine is a 2003:

https://www.bicyclebluebook.com/Sear...81&model=40995

Am sure it wasn't designed for anything over 23c tires

redlude97

on a steel or aluminum bike no problem