Questions about 6" VEX/WCP traction wheel tires and treads

Hi CD,

We designed and built our drivetrain with 6" Vex traction wheels, and made the rookie mistake of not ordering enough tires for them. Unfortunately, the 6" tires (217-2860) are now out of stock for the 2018 season (please PM me if you have extras, we’ll pay shipping and then some for more!) and are considering a few different wheel options as replacements.

We can:

  1. Stick with the Vex traction wheels, but rivet this roughtop tread to them. Any opinions about this? I can’t find any information on Vex roughtop tread out there. This is probably our best option, assuming there aren’t any wear/traction issues other teams have experienced with them.
  2. Switch to AM KOP wheels. (would probably be fine, just don’t like their stigma)
  3. We try to source 6"x1-1/2" Colsons. Probably the worst option of the bunch, as it seems like Colson has stopped making them, and unless another team has any, there’s no way this happens.

Dead Axle 6x1.5" colsons are still very available! The robotics specific colson resellers that are not named vexpro always have pretty bad inventory. McMaster always has pretty amazing inventory.

McMaster P/N: 2829T14
https://www.vexrobotics.com/colsonhubs-g.html

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That might be possible, but our drive is designed to be live axle. Our belts run on the other side of our framing from the wheels (WCD style).

Also, wouldn’t using Vex Colson hubs require pressing the stock Colson 1/2" round hubs out of the wheels? I was under the impression that that was virtually impossible, and has a chance of destroying the wheel.

Riveting on the tread will work fine. We’ve done it for a long time.

We’ve also been riveting tread for awhile. We’ve found that the best way to hold the tread on while you rivet it is with hose-clamps. 1 or 2 depending on your wheel width works great.

The hubs currently in those part number colsons are a loose fit metal sleeve inside two plastic “hubs”. The metal part has to be ziptied to the wheel so it doesn’t fall out and the plastic hubs come off easily with two flathead screwdrivers or one and a hammer.

If you have access to a broach for your preferred axle shape, live hubs are fairly easy to make. If you don’t, riveting tread onto your current wheels is probably the best bet.

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How many rivets per wheel do you guys use? How often does the tread wear out?

We use four rivets, two at each end of the strip. We use blue nitrile tread, available on McMaster or AndyMark which doesn’t wear down very fast. Towards the end of last season (after 40+ matches) we saw some wear but I wouldn’t have replaced the tread for another 10-15 matches.

Do you have a part number on McMaster? This looks like a really nice option, assuming it can be cut to 1-1/2" thick.

Yes 5994K9. Sorry that link didn’t quite work the way I thought.

Sweet, thanks. Do you guys cut it with a band saw, or what? Thinking of getting the 3" variety and slicing it up

Ninja edit: ships in 1-2 weeks :frowning: gonna have to go with Vex treads

My team found ourselves in almost the exact same situation as well.

We’ve decided to go with the KOP wheels for ease of use and general availability.

If you go with the roughtop tread, VEX sells the tread into pre-cut 1.5" wide pieces. May save you some hassle.

  • Sunny G.

We’ve cut it with a band saw before but it’s not as straight as we would’ve liked. We normally cut it on a table saw. You need to be very careful doing it though.

Because the tread isn’t flat if you try to cut it by itself it kicks back worse than anything I’ve ever seen cut on a table saw before. The best thing to do is to put a piece of cheap plywood or OSB on top of the tread and “sandwich” the tread between the table and the wood. This keeps the tread nice and flat and helps remove most of the uneven cutting caused by the tread pattern.

A band saw would probably work okay if you cut the ~18" sections and then cut them in half to get the 1.5" sections.

Edit: The McMaster tread says it’ll ship Monday morning.

Am I missing something?

This says 1-2 weeks: McMaster-Carr

Huh. It told me it would ship in the morning when I added it to a cart. Maybe try calling them tomorrow?


Selecting a width says Ships in the morning. No width says 1-2weeks.

We riveted tread to those wheels recently. Used .375-.5 depth 3/16 dome headed rivets. Worked out great!

We’ve used the blue roughtop tread on 4" kit-wheels in 2014 & 2017, we just throw them on the lathe to take off the nubs and then use small wood screws with a pilot hole to attach the tread. I think we had one rip halfway off in 2014 (each set saw 50+ matches in 2014 & 2017) We typically order wide and cut to width, band saw works well but you lose some to the kerf, clamping a straight edge on it and using a sharp knife works too. Plan on trying with the 6" kit-wheels this year.

If you select the 3" wide option, it will change the availability from 1-2 weeks to “in stock”