Originally Posted by
prathmann
No, just as RetroGrouch correctly explained about the advantage of a supple sidewall, there is a similar benefit to having a tread pattern (or lack thereof) that avoids energy losses due to the rubber squirming in the area of the contact patch.
One example of a poor design was the old Specialized tire of the late '70s that had a solid rubber center in the tread with fairly deep grooves on both sides. As the tire rolled, that solid rubber center part would be pushed out to both sides by the pressure from the road at the contact patch. That repeated deformation of the tread rubber takes energy which then goes into heating up the tire tread instead of propelling the bike. A similar tire but with a smooth (slick) tread area suffers from much less rubber deformation and therefore has less rolling resistance. Knobby tread patterns result in even greater rubber deformation in the contact region and should also be avoided to get lower rolling resistance in applications where the knobs have no offsetting advantage.
If you want to take the tread pattern argument to an absurd level then yes, a slick tire will have less rolling resistance than a knobby tire.
I think what you are really talking about is construction - by this I mean a the choice as to how thick the tread layer is, whether there are varying thicknesses or whether or not different compounds are used in the construction of various sections of the tire - and casing deflection. I agree that these both play critical roles in the characteristics of a given tire. Much more so than tread pattern.
The point that I am making is that if you look at a similar category of tire (since we are in the 41 lets restrict it to road tires and since I assume we are talking about speed lets limit this to performance oriented tires) you will see minimal tread patterns. Why is this? It is not because tread improves traction in any way. It is there to instill confidence in consumers - to make them feel like the tire will have good traction.
Based on tests done by Continental, bicycle tires - and bicycles in general - do not have the mass or force to hydroplane and that tread pattern had absolutely no effect on traction. Perhaps I misspoke in an earlier post when I said tread vs no tread has no difference. This is not entirely true. The fastest tire is a slick tire because of reduced casing deflection vs a tire with tread. The thing is that this factor is FAR down on the list in terms of what makes a faster tire.
Construction and compounding tops the list. These also affect traction the most. Tread is an after thought and often designed by the marketing department
not the engineers. That should tell you something.