Originally Posted by operator
This is false, your bike never travels fast enough for hydroplaning to become an issue. The "treads" on a road tire are decorative issue only. A slick tire will provide the most grip in both wet and dry conditions on paved surfaces. Automotive dogma does not apply here.
It's a wonder why tire manufacturers feel the need to put any treads on tires at all. I guess its for the general public who think the exact thing as above ^. I would love to see all slick road tires become more prevalent then decoration tires.
http://www.sheldonbrown.com/tires.html#hydroplaning
http://yarchive.net/bike/tire_directional_tread.html
+1
Perfectly slick tires are the best for on-road applications. (1) Bikes can't hydroplane, and (2) a perfectly slick tire maximizes the area of tire rubber in contact with the ground, and thereby maximizes traction. As Jobst Brandt explains it, tread can improve traction IF AND ONLY IF the ground is actually soft enough that the tires can actually make a dent in it.
Sheldon Brown also agrees that tread directionality is irrelevant for the road:
http://sheldonbrown.com/tires.html#direction