[London]

Any of you folks who race ever run 25mm tires? I've always used 23s and train on the 25s to gain a bit of protection for my rims. When I time my rides with the different widths I cannot see a pattern of better times with the narrower tires. But on race day, I stick on the 23s thinking they will be faster. I figure this is wishful thinking.

I know there is more to a tire than its width, just wondering if anyone races on 25s. The only thing of note I've seen on tire selection is a tendency toward faster times on pure slicks vs. any tread. This if both tires are of equal quality and weight. I really think any tread is a speed killer. All my racing is time trialing so seconds count. A 2 second gain per mile is to kill for. I find slicks are about 3-4 seconds faster than treaded race models.

[chh55]

I use 23 for everything. I got a deal on some Vittoria Open Corsa 21mm a few years ago but I didn't notice any real difference (other than they flatted a lot!)
If you're into shaving seconds you must consider the aero factor of the tire as well as rolling resistance. Zipp has done studies on this and it turns out to be significant (who'd a guessed!) and they make a aero tire just for TT events. As far as I know only in tubular format.

[London]

Originally Posted by chh55

I use 23 for everything. I got a deal on some Vittoria Open Corsa 21mm a few years ago but I didn't notice any real difference (other than they flatted a lot!)
If you're into shaving seconds you must consider the aero factor of the tire as well as rolling resistance. Zipp has done studies on this and it turns out to be significant (who'd a guessed!) and they make a aero tire just for TT events. As far as I know only in tubular format.

55, I've got disc wheels and already use carbon aero front. Simply curious about width. Have never dared going below 23. You have used 21s? Are the flats pinch type? This is my fear. (I weigh 160 lbs)

When good clinchers came available 20 years ago, I stopped all tubular use. I never liked tubulars. They puncture on looking at them too hard. Plus, once you flat, a change in the field means poor glue adhesion and a careful ride home so you don't roll a tire off in a corner. No thanks. Modern clinchers are a marvel of engineering.

Thanks for the input. Some day I'll try a 21 or even a 20.