It depends on a lot of factors. Unless your wheel manufacturer recommends a size (for instance, some will specify a size that matches the rim width very well to reduce aerodynamic drag), just stick with 23's. You won't really notice any difference, except that 23's are easier to find.
Looking at the table at the end (for tubulars), it's interesting to note that there is no clear correlation between width and rolling resistance.
The Crr, which is higher when there is more rolling resistance, is the first column and the table is sorted on it. The five fastest are all cotton outers with latex inners, but all but one are smaller than 23.
The only 19 tested on the list is constructed of different materials, and so comparison isn't really accurate. It would be interesting to find a Crr on a cotton/latex 19 to see where it fits in.
The other interesting thing to consider -- many tests pump tires to the same pressure (this one did pump the 23's to a lower pressure, but if you notice -- all of the pressures used are far lower than would actually be used on the track). But obviously a 19mm tire pumped to 160psi will deflect more than a 23mm tire pumped to 160psi. The studies address this by saying that a 19mm tire pumped to it's max is a harsher ride than most people want. But, if your focus is only on speed, then harshness of the ride is a minor concern.
So, the moral is: 1) Ride what's safe (traction on your riding surface), 2) Ride what the wheel manufacturer recommends if anything, 3) Ride what you can easily buy and replace (19's might be nice, but if you have to wait a week to replace a flat, is it really that great?), 4) With a tubular, if it's glued poorly, the best tire will ride slower than the worst tire glued correctly (and you should learn to do this yourself -- USA Cycling will suspend a rider who rolls a tubular in a race, so why trust somebody else to do it?).
Submitted by jeffhopkins on Fri, 2010-06-04 08:42.
23 are good, 21's will work. pump them up hard if you want to go fast, less if you like comfort. I like fast, so 150 at least. +1 on tim, glue them good
700x23, generally. It depends
700x23, generally.
It depends on a lot of factors. Unless your wheel manufacturer recommends a size (for instance, some will specify a size that matches the rim width very well to reduce aerodynamic drag), just stick with 23's. You won't really notice any difference, except that 23's are easier to find.
Tim
And they have more contact
And they have more contact area for those nights when the track gets a bit slick for whatever reason.
for those curious
not sure if it's accurate but it's an interesting article:
http://www.rouesartisanales.com/article-1503651.html
Looking at the table at the
Looking at the table at the end (for tubulars), it's interesting to note that there is no clear correlation between width and rolling resistance.
The Crr, which is higher when there is more rolling resistance, is the first column and the table is sorted on it. The five fastest are all cotton outers with latex inners, but all but one are smaller than 23.
The only 19 tested on the list is constructed of different materials, and so comparison isn't really accurate. It would be interesting to find a Crr on a cotton/latex 19 to see where it fits in.
The other interesting thing to consider -- many tests pump tires to the same pressure (this one did pump the 23's to a lower pressure, but if you notice -- all of the pressures used are far lower than would actually be used on the track). But obviously a 19mm tire pumped to 160psi will deflect more than a 23mm tire pumped to 160psi. The studies address this by saying that a 19mm tire pumped to it's max is a harsher ride than most people want. But, if your focus is only on speed, then harshness of the ride is a minor concern.
So, the moral is: 1) Ride what's safe (traction on your riding surface), 2) Ride what the wheel manufacturer recommends if anything, 3) Ride what you can easily buy and replace (19's might be nice, but if you have to wait a week to replace a flat, is it really that great?), 4) With a tubular, if it's glued poorly, the best tire will ride slower than the worst tire glued correctly (and you should learn to do this yourself -- USA Cycling will suspend a rider who rolls a tubular in a race, so why trust somebody else to do it?).
Tim
23 are good, 21's will work.
23 are good, 21's will work. pump them up hard if you want to go fast, less if you like comfort. I like fast, so 150 at least. +1 on tim, glue them good