[Andrew_L]

Having used all three kinds of wheels, here are my experiences:

Colsons: I haven't found tangible evidence that a wider colson wheel provides more traction than a thinner one, but this is mostly due to lack of serious testing. The beauty of the colson wheel lies in the soft rubber's ability to heat up during a match and slightly deform such that it "digs" into the carpet in the way a treaded wheel does. Another advantage is how incredible colsons wear, to the point that you can run the same pair all season and never need to change them. This cannot be said about the other kinds of wheels.

VersaWheels (W-tread): Personally, I think the W-tread versawheels have the most traction out of any wheel listed here, with its hard plastic cleats clawing into the carpet when run for the first time (and in my early tests, clawing into my skin with ease, requiring a quick visit to the first aid kit). The problem with these wheels is how incredibly quickly they wear down. As soon as 3 matches in a fresh set of wheels will show signs of rounding on the normally pointy jagged cleats. Once some rounding appears the effective life of the wheels is nearly over, with a few more matches of hard driving they'll be worn down to near round with some small bumps, losing the grip and traction from the now worn down cleats. The key to using these wheels successfully is to swap them out every few matches. I personally haven't swapped out more than twice an event, but I have friends who drove their robots more aggressively than my team who had to go through 3-4 sets of wheels per event. These are great wheels if you have enough stock to swap them out multiple times per event. Just keep in mind that on a 6 wheel drive robot, 3 swaps per event through 3 events is 54 wheels, and at $6 a pop, that's $324 you'd be shelling out just to keep good wheels on your robot through the season.

Treaded wheels: Treaded wheels are always a solid option if you choose the right tread. There are many different treads out there to use, and I know some people have their tried and true special tread they like using (cough cough green 469 tread), but from my experiences there are really only two treads worth considering: Blue nitrile roughtop tread, or tan wedgetop tread. Blue nitrile roughtop tread is the ideal FRC robot on carpet tread. They last long enough that you don't need to swap them out nearly as much as you do the versawheels (but you should be swapping the tread out during season) and they provide enough traction to get through most pushing matches. The tan wedgetop is a niche tread that shows its strengths with non-carpet materials. This tread style was popular in 2012 when there were lots of non-carpet surfaces for the robot to drive over and interact with. On these surfaces, the wedgetop tread had greater traction than the roughtop treads did. It has also been found that colsons also have more traction than most treads on non-carpeted surfaces, though I have not seen a test that compared colsons and wedgetop tread on non-carpet surfaces to see which ultimately had the most traction. Either, however, holds more traction than roughtop tread on these surfaces.

With versawheels and treaded wheels, I have seen evidence that a wider wheel provides greater traction because there is more interlocking surface area with the carpet. Logically, this is not relevant on non-carpeted surfaces that the wheels cannot "dig" into.

These are just my experiences with each kind of wheel, as always, your mileage may vary. Personally, I intend to use colsons on most robots I design in the coming future because the ease of maintenance (aka the fact that there is none) and the universally competitive traction on nearly all surfaces one would encounter on an frc field.