[quote]Everyone THINKS they know, but they don't. Josh at Zipp would seem to have the most informed perspective, but even he ultimately comes to the conclusion that any real differences are small. [/quote]
He may SEEM to have the most informed perspective, but that doesn't necessarily mean he does. His reply is full of more holes than a block of swiss cheese...
For example, most of the best testing clinchers DO have puncture belts (Michelin Pro Race and Vittoria Open Corsa to name a couple).
Oh yeah, here's another: the posted test results (Tour) are also with the clinchers using a butyl tube (not latex)...and they're STILL gobs better.
Let's see...one more....tubies have a structure (glue interface) which inherently causes higher energy losses for a given deformation, yet when tested on a CALSPAN type rig, somehow this structure results in fewer losses? Come again?
Anyway...I wonder what the difference is in margin on a given carbon tubular vs. the same model clincher rim? Hmmmm....
In all honesty, it actually warms my heart to see people still claiming that tubulars are as good as clinchers :-)