Originally Posted by Rayxt

Completely counter-intuitive and defying general cycling wisdom, but based on this Schwalbe test report any way you cut it a 700x42 slick (or fatter) like the Specialized Borough @ 80psi will have lower rolling resistance than anything narrower, bar none!

From the graph of energy input to perform the same amount of work, this equates to 20-30% more effort (or calories burned!!) to go the same distance. And that differential gets bigger if you let narrower treads run under maximum pressure.

What Schwalbe say is the optimum footprint is a circle, ie the diameter in the plane of rotation (the rim) is the smallest (for the same applied load). Therefore as narrower tires flatten out along the rim, not more evenly across it like fat tires, their rolling resistance is much higher.

Narrower tires will inherently suffer more wall damage caused by this kind of longitudinal flexing, much more so if habitually under inflated, or their cross-section is too small for the weight carried,

My experience with Borough is they're light, fast and very tough.

For flat-free commuting (and I've done thousands of miles without a flat stopping me getting to my destination) you must put in Slime strips or Mr Tuffy and load up (Schrader valve) tubes with Goop or Slime.

If you're over 160lbs/75kg (or carry heavy loads) and want a fast ride, the Borough tire which inflates to 80psi is best way to get it.

It goes without saying you should have (preferably) 622x19 rims, although 17.5mm width would do. And depending on your weight and the loads, double wall, double eyelets and heavy spokes to match.