Challenger Extreme 2.86" 16" 2.5"

That is correct. Camoplast's answer to unwanted paddle contact with the edges of the tunnel bolts....warranty concerns.

Yup.... the only way to get full 16 is to get the 3.0 pitch

I thought the same thing when I opened the box. It makes almost no sense. The stock track is a full 16" paddle to paddle. If the track is not aligned it will rub, but why not send a note with each track explaining that if track is not aligned properly that damage will occur. I would much rather have a full 16" paddle to paddle then this 15 1/4". Call camoplast and let them know. The only way this will change is if we let them know. There is good news though, the track still works much better than the stocker. It would be interesting to see how much difference we would see between 16" and 15 1/4".