A lot of the choice on tire size is dependent on rider weight. I would not recommend a 700 x 23 to a 250 pound rider while it is fine for a 150 pounder.
Also within any tire size rolling resistance seems to vary inversely with puncture resistance so you choose your tires, once size is determined, by how much puncture resistance is desired.
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Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro
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