How well do the rears line up with the fenders? I have front RT-S wheels and I am looking to pick up some 15 in rears over the winter and I am still on the stock IRS as well.
They're tucked in a bit, but seem to function just fine. Improved my 60 a lot. From 2.1-1.7. But I'm still practicing technique and playing with tire psi. So there's probably room for improvement. BTW my rears are 16 inch. If you go 15 you will need to grind the calipers. Reason why I opted for bigger.