[kevincrispie]

971 used a material called Ballistic Nylon this year, and it helped us enormously in getting out of friction pins. Our entire drivebase design, from the shape to the bumper material helped us evade defense and was a big reason why we were so successful.

Ballistic Nylon has a coefficient of friction of 0.3 on the normal Cordura, compared to a coefficient of friction of 0.5 of Cordura on Cordura. It terns out this difference is enough to get out of most pins. Our testing showed that we could drive out of pins even without an octagonal shape.

Many other teams have used low friction bumpers this season and in the past. 1678 and 1717 both used the Ballistic Nylon fabric this year. Other teams (and they will have to correct me if I get these fabrics wrong) include 1114 and 148 using sailcloth and 2056 using some kind of vinal. For championship, 254 decided to change from Cordura to sailcloth, and it really upped there performance. They were much harder to defend at championship than at SVR or on the practice field. Sailcloth has a coefficient of friction of 0.25 on Cordura, but tends to be more expensive that Ballistic Nylon. It is also less durable than Ballistic Nylon.

We also experimented with using Sailkote on our bumpers (Sailkote is a sail lubricant for those who don't know). This seems to only help significantly with the actual sail fabric, and take the coefficient of friction on Cordura down to 0.2 from 0.25. However, we'd likely need to get some sort of Q+A ruling to do that to be safe, as it becomes a user applied material to the fabric. We tried spraying it on Ballistic Nylon and it did not work well enough to justify the effort involved and the extra cost.

Some low friction materials are not as sturdy as Cordura, which is why we did not use them. We did stress testing on the Ballistic Nylon and found that it was about as strong as Cordura. Ballistic Nylon does wear, but not to the extent that it would not be considered a "smooth, rugged material" as specified in the manual. Materials like silk are slippery, but just fall apart during the rigors of FRC gameplay.

Also, a note on the pleather material that HOT uses: they would be better served to talk about this than me, but I was talking to Mike Schreiber at championships, and he mentioned that pleather is very slippery on Cordura, but gets stuck to field elements. The positive of these other materials is that generally doesn't happen.

There's been a lot of advancement in bumper materials over the last couple years, and it definitely makes a difference in on field performance.

Hope this helps.