[Holtzman]

Back in August Team 1114 was asked to construct a 6 wheel chassis to test out the latest version of the IFI traction wheels. Our testing featured six 4” x 2” Traction wheels with 3/8” id ball bearings. Our testing included many repetitions of heavy driving, impacts, quick starts and stops, and jumping the robot off a ramp.

Having not previously used the IFI traction wheels, I did some research into the problems that teams encountered with the first version of the wheels. Here were the major concerns:

- “The treads come off too easily”
The new wheels come with large headed 1/8” aluminum pop rivets as opposed to the original standard headed rivets to help ensure the tread stays attached. We had no problems with treads detaching over the course of our testing.

- “The rim of the wheel bends inwards, causing a structural failure”
The new wheels feature interlocking tabs between the rim portion of the wheel, and the side plates. These interlocking tabs are to alleviate the problems some teams encountered resulting from the rim portion bending in following a sharp blow to the perimeter of the wheel. Throughout our testing, we experienced no bending in this fashion despite repeated attempts to produce it.

- “The fasteners came loose”
Last year, some teams complained about the flathead Phillips fasteners repeatedly coming loose between the side plate, and the rim portion of the wheel. The wheels now feature stainless steel button head screws with an Allen drive. The PEM (rivet nut) fasteners in the rim portion were also swapped out in favor of ones with nylock inserts. Throughout our testing, we experienced no loosening of these bolts. Teams must, of course, ensure that these bolts are tight on assembly.

Another nice new feature is the new bearing retainers, which are a welcome improvement over old bulky ones.


Our only real grievance about these wheels was on assembly. As mentioned previously, the wheels feature interlocking tabs to help prevent the rim portion from bending in. These interlocking tabs over-constrain the rim portion to the side plate making the bolt holes difficult to line up at times. This is due to the bend tolerance on the rim portion of the wheel. On assembly, we drilled these holes out to a loose clearance on the bolt. I am told by a representative from IFI, that this revision will be made to the production models.

All in all, we were very impressed with these wheels. We had no problems at all during the testing phase with these wheels. After going through our rigorous testing process, Team 1114 is fully confident that wheels can withstand the rigors of a full FIRST season. If the game calls for a wheeled robot, there is little doubt in our mind that these would be the wheels of our choice. The strength to weight ratio is exception, and the cost is not prohibitive. In short, these new wheels are a great improvement to an already top of the line product.

These v2 wheels worked out great for us, but I’ve also, just this morning, learned that there is a v3 design in the works. I’m confident that regardless of the further developments IFI takes, the new wheels released in 2007 will fully address the problems voiced last year. Remember, design is an iterative process.