Wow, this is an OLD post. Still good for starting an argument though!!!
I anecdotally find that matching the depth of my tread to the roughness of the surface works out well. (roughly analogous to shoota's graph above).
I ride short knobs on shallow gravel and hard pack
I'll ride deeper knobs on softer and rougher terrain
Riding slicks in ideal conditions is amazing (i.e. velodrome), but deteriorates rapidly as the surface deteriorates)
Big Ones are easy to ride at 15mph. Above 20mph the weight (on rolling hills) and aero make them difficult to spin up in near race conditions.
Originally Posted by
fietsbob
for the ones not OCD & in computer software writing..
Generically
the slick tires roll better on paved roads ,
the tread blocks there for dirt traction lose energy squirming as they roll ..
Friction creates heat.
....