Why is there no rear outside 8" wheel on sidewinders?

[**sj**]

I have the JT Big wheel kit to put on my Winder. Any of you that have used the kit in the past on a viper... have any problems with the wheel getting messed up? What I mean is they are 100% plastic w/no rubber around them like normal wheels. Yes I realize the trihub is the same. I don't plan to stud so I don't expect any issue from studs rubbing on them. Just seemed odd for the outer wheels not to have rubber on them. The only time I have ever seen that was when someone went with billet ones.

not an issue...

 

[AXR]

not an issue...

Thanks!