nitrile roughtop vs. smoothtop

[Mike Yaremko]

My team this year is using the andymark high performance wheels we want to use nitrile as the treads. I was looking at McMaster Carr and i saw that there were two options roughtop or smoothtop. We're wondering which surface is better for traction; roughtop or smoothtop? Or if you have any other recommendations for better tread material, what are they?

[Swampdude]

My opinion is the wedgetop gum rubber. I've found it to be much stickier than the rest, although the roughtop and nitrile will be more durable.