I was looking and I saw that Polaris is going to a 9" rear rim? They used to use the 10". Why the change? were the 10's getting wooped?

 

ya polaris is offering them because they are a better race rim... they were trying to stop it from sliding so much around corners..
they also shortened the swing arm 1 1/2".

 

Besides going down to the 9" rim, they also went with a 4/110 bolt pattern (I think). They say they have new hubs to fit standard wheels. And the most standard wheel is a 4/110 pattern. Then you also get more tire choices in a 9" size.

 

Difference in wheelbase is only .5 inch. (1/2). Not 1 1/2"