SinGate

I ride with a 700x23 tire but a friend swears that he is much faster on a 700x20. Does it make that much of a differance, and what other concerns does riding on a thinner tire raise?

Walter

I used to ride as narrow a tire as I could find, usually 700X19 and, in the old days, 27"X1. I like 700X23, a little nicer ride and every bit as fast IMO.

Many others like 700X25 or even wider and report no drop in speed.

lotek 

I ride a 700x22 most of the time (tubular).
I don't know that the 3mm difference will make a huge
difference other than the 23 will be that much more comfortable.

Marty

Rossgo

i find any lower than 23c makes me unsable for sprinting .

smurfy

I ride Conti SS Ultra 700 x 18 tires on my Colnago. Got 'em cheap thru Performance on a closeout. They ride great, much like a fatter tire, very comfortable, even with the 150 lbs of air pressure they are rated at. Broken beer bottles don't like them, however!

TimB

20C to harsh due to higher pressures
23C just perrrrrrrfect
25C too heavy for serious racing but can be great for training/commuting.

Random

For what it’s worth, I switched from 23 to 25 this year and haven’t noticed anything. In fact just set a new personal best. The extra bump in size is just more comfortable.

velo

I like the crisp feel of high pressure, so I go 700x20 on the road. I have tubulars that are 19s and 22s, though, too.

Arsbars

and just too hard for me.