Tire Height/Profile HELP!

[cornelldewitt]

Hang on, this is a long one.

I rode Conti Super Sport 28mm tires for the better part of two decades on a 1991 Serotta. Love them--nice ride, and I live in NYC and never got a flat. Plus, they were the biggest tires I could squeeze on to my Davis Phinney (I'm also old, so I like bigger tires.) I've always avoided the Gator Skin tires 1) because they reportedly use a harder rubber compound and so the traction is apparently compromised, especially in wet conditions--no thank you-- and 2) see above--I'd never gotten a flat on the Super Sports.

Then they discontinued the Super Sports. So I bought a pair of Conti Grand Prix 4 Season 28mm tires. Popped them on and, man, the clearance between the top of the tire and the rear brake was TIGHT--WAY less clearance between tire and brake than the Super Sport, but they still fit, so I didn't give it too much thought.

Rode a couple hundred miles, and LOVED them--much better ride than the Super Sports. Although seemed more prone to tiny rocks & leaves getting stuck between the tire & brake with such tiny clearance. (This is just on the rear tire, fork has much more clearance.)

Recently I rode on the roller trainer for a little while, and by the end of the ride, the top of the tire was rubbing the brake. The only thing I can figure is that over time, or due to the heat of the metal rollers, the tire broke-in, or warped ever so slightly and expanded by about half a MM or so--just enough that it now rubs the brake. Argh!

Pop off that tire and put an old Super Sport 28 on the rear wheel. Still fit great. Throw the old calipers on it, and it turns out the Conti Grand Prix 4 Seasons 28mm tire is THREE MILLIMETERS TALLER than the old Super Sport 28mm tire. WHAT?!

Inflated to about 85psi (did I mention I'm old) the Super Sport 28 is 24mm from outside of rim to top of tire; the Grand Prix 4 Seasons is 27mm.

I tried to tell my wife that clearly the only solution is that I need a new bike, but she didn't buy it. And no, I'm not going to just get 25mm tires. Don't be fatuous. I've ridden 28mm on this bike for decades and I'm only getting older. Weird, but true.

So my question is, does anyone have any experience with the HEIGHT of the Grand Prix tires? Anyone have Grand Prix 5000 tires on their bike they can throw calipers on and check the height?

Any insight on tire height in general? Anyone recommend 28mm tires that are closer to 24 or 25mm in height? Lower-profile tires, generally?

Thank you for listening!