Silly question can I put the same height rear tires as fronts?
I want to give my sons quad a little more lift he has a 2010 phoenix 200 with 21x7x9 fronts and 20x10x9 rears I want to put 21x10x9 rears on there but am worried I would have to raise the front size as well but his front tires are like new and it's a financial thing right now.

 

I don't think an inch would make any difference but you're only gaining 1/2" lift and only on one end. It seems kind of pointless.

 

A 200cc should even handle 22" no problem. My friend put aggressive Swamp Witch 6ply 24x11-10 "Rear" Mud tires on his 300cc Kawasaki Lakota OK.

I went from 25" to 26" front and back on my little 350 without any issues.

 

I had a Phoenix for a year or so, and it is a nice quad with excellent
suspension, but pretty weak on power. Since it has full auto tranny and
a drive shaft final drive, I would not increase the rear wheel size because
you then have a higher final drive ratio. If you had chain drive, then
you could compensate by swapping the drive sprocket for a smaller one
(or the driven sprocket for a larger one).

It does not matter what you put on the front, within reason.