Roughtop or Wedgetop?

Our team used wedgetop, 6 inch plaction wheels this year. However, after 61 matches and many other demonstrations, our tread is worn down past the plastic on the wheel, and it’s time for new tread. I was looking at AndyMark and saw that “Roughtop” tread was also an option. Any opinion on which is better? Our team is big on balancing, so traction on the bridge is important to us. Thanks!

Roughtop also wears significantly. We’ve used it since '08 in various situations, and none of ours has lasted more than a season (~ 2 events worth of matches plus minimal practice and some demos). We have never used wedgetop, but our own experience with roughtop and what we’ve heard of wedgetop makes it sound like they wear similarly, and they are a very similar material (roughtop is nitrile while wedgetop is a natural rubber). I’m sure other teams have more detailed anecdotes of comparison. Also, I’ve heard that Colson caster wheels have a very long life and similar performance to traction wheels using Andymark tread, but again have never experienced this first hand.

For traction on the bridge, it has actually been determined by some (including 2175 in qualitative tests) that the 2012 kit wheels have better traction on polycarb, and I think the Colsons may as well.

10 years ago we set up a traction testing rig at the championship for teams to test out there treads; it was basically a spring scale mounted to a frame that you hooked on to the back of your robot, and we recorded the max static force on a carpet sample. We were using green brecoflex continuous belts at the time which were (and still are) pretty expensive and they had the most traction, but not by much. Roughtop tread is basically the same material. Wedgetop tread, which many teams were using then, was a pretty close second; I think the results were within 5% so it could well have been in the scatter of the data and I would consider them equal. Just from observation and qualitative testing, the wedgetop seems to do better on smoother surfaces (like this year’s ramp) so I would probably lean that way if the game required it.

I can’t speak to tread wear; they’re all relatively inexpensive to replace so I wouldn’t make a decision based on that if I could choose based on performance.

A lot of people will recommend the use of blue nitrile roughtop tread since it is supposedly the longest lasting and has great traction on carpet. It is more durable than the orange natural rubber tread sold by Andymark. Although between the two, I am not sure if there a substantial different in traction.

Every team has different experiences with tread - understandably though, due to different wheel sizes, drivetrain fps’s, driving time, and handling.

Hello, I am from 3310 Team Black Hawk and this year we used 6" IFI Wheels with roughtop tread. We used the roughtop tread throughout the Bayou Regional and also the Dallas Regional, and went on the the Championship in St. Louis. After St. Louis we chose to attend the Razorback Regional in the offseason and when we arrived, during practice we realized that our tread was shreded and we were unable to climb the bridge as quickly as we desired. We removed our roughtop tread and switched to wedgetop, and we experienced significant increases in traction and speed. We used the wedgetop tread throughout the Razorback Regional and also the Indiana Robotics Invitational. Our wedgetop tread shows little to no signs of wear. I would highly suggest the idea of trying IFI wheels in the future.

Thanks,

Tyler Bledsoe. 3310 Black Hawk.

Thanks for the suggestions guys!

We’re really looking for traction over wear resistance- it only has to live through one more competition. I think that we’ll stick with wedgetop treads, in part because of Gary Dillard’s observation that they may work better on smooth surfaces, like the ramp. If they’re pretty similar, we’ll stay with what we know. Thanks again!

In my team’s experience, blue nitrile tread isn’t much better than orange in terms of wear. It still wears relatively quickly, and just gets murdered by trying to use it on cement (for demos and such). Also, because of the toughness of the backing material, it is very hard to cut to size, even with sharp razors. It might have slightly more traction than other types of tread, but I’m not sure we’ll be using it again next season.

In our experience the blue roughtop wears like a champ (under FRC applications, not cement). It easily last a season of competition before being completely worn. We generally replace it after 2 events just to make sure we’re running the freshest of tread.

It cuts really nicely on a bandsaw, razor blades are not the right tool for the job. Table saws also do an excellent job.

This year our team did a bunch of testing for traction on both the carpet and the bridge between kit wheels, roughtop, and wedgetop. We found that the kit wheels worked on both surfaces the best. The next best tread was the wedgetop. Roughtop works great on carpet but had the least traction on the bridge. We have used roughtop for year and love the grip on carpet and it wears better than wedgetop. It also has to do with which material you choose. McMaster-Carr carries both types under inclined conveyor belting. It cuts easily on the table saw and a good pair of fiskars will cut right through it to get it to length.

Sharp razors would be a improper and very dangerous way to cut it.

A nice pair of tin snips does a good job or even better a set of utility shears.

Rough top, wedge top, tan or blue – nah we recently got the Colson religion.
Love the price, love the wear, love the traction. I can’t see us going back unless the field surface is something weird.

We used black roughtop on 4x1.5" and 4x2" IFI wheels, and they’re still running strong after five competitions and ~18 demos. The tread on our center wheels is worn considerably, but they’re not bald and the robot still drives fine.

I also second the point on cutting tread with the band saw.

Where do you get black roughtop?

We’ve used wedgetop on both our 2011 and 2012 robots. 2011 experienced a lot of wear and tear over the course of a pre-season scrimmage, extensive driver training, regional, and championship. In 2012 we had to replace some tread during our second competition and then again before our first off-season event. Looking back, roughtop sounds like it would have been a better fit for 2011 in terms of wear but 2012 we would have stuck with wedgetop because it didn’t slip on the bridge. In the future we are looking into Colsons because they are cheaper and last longer.

Brandon, you guys should get more wedgetop to finish out the season and you’ll find uses for the leftovers down the road!

I’m not heavily into mechanical or ordering parts, so I’ll try to get back to you about that. I don’t think we bought it this year, I think we just pulled it out of storage, so it could be difficult to track down.

EDIT: Sure, go with them.

Search McMaster for “incline conveyor belting” the SBR stuff is black

McMaster has always been my source for tread

http://www.mcmaster.com/#rough-top-belts/=j4dcax

As far as the black tread goes, you would want the Extra-Grip SBR, not the “Oil-Resistant Neoprene.”

It’s great that they’ve lasted that long, i thought the constant turning would rip those things apart.

I’m not really the parts lifespan expert, but from the responses here, I’m a little surprised too. We’ve got one more offseason event, and they’ll have probably had enough after that.

Kind of a thread bump, but between blue nitrile and black SBR, what do people suggest?

Where is blue nitrile available in the correct width for plaction wheels?