Originally Posted by
Sailboat Bob
Setting up a racer for the season. Concerning speed and nothing else whats the best thing for 27" clinchers?
The only tires that are available in 27" sizes and having been tested for rolling resistance would be the Continental Ultrasport and Ultrasport III, although versions of the Vittoria Zaffiro that were also tested might be similar to the 27" version of the Zaffiro.
The Continentals tested well, actually as good as some of the higher-level racing tires from other brands.
The tested 700c Zaffiro was not far behind in terms of rolling resistance.
I've ridden on the 27x1" Pasela tires, which measure a full 26mm wide on my touring rims, and these seem to ride and perform well, but I probably couldn't notice a couple of watts difference (per tire).
The better-performing tires reportedly don't suffer as much additional rolling resistance incurred by lowering the pressure by any increment of pressure.
At higher pressures, different tires may perform more similarly, unless the tread is deep which would intensify the flexing of the rubber tread (and incur energy losses).