I think the team rollers can allow you to change to another helix angle just by making a change while it's on the sled, it rides on another side of the helix or something, this way you can have a trail angle and race angle all in the same helix. This is what I was told by a guy who has one for his polaris anyhow......
there is also something different witht he polaris ones anyhow because they have a second angle for using the electric reverse, don't know how that works, never sized it up too well but it's very noise when shfiting from forward to reverse, it' clunks everytime.