I am planning on changing the sprockets on my Raptor soon but I need some info.
If I put a 12t on the front how many teeth larger on the rear can I go without lengthening my chain.
Also how many teeth larger can I go with a PRM swingarm skidplate without having to shim it down. I have the skidplate but I have not installed it yet.

 

You wont have to lenghten your chain at all! I have a PRM skid on mine and I have asked the same question about the rear and I havent received a answer but I think you can only go up to a 42 teeth rear without shimming the skid down stock is a 40. You can run an 11 on the front and leave the back one stock thats what I did and it works good for the woods able to ride 2nd and 3rd in tight stuff. The 11 just wears out faster so keeep an eye on it mine lasted me 1.5months of hard riding but there cheap and easy to change so its worth it.