I want to gear my 300ex down to a 12 tooth front sprocket to pull my new tires better. I think if i gear it down the extra tire height will make up the loss of speed and it should be equal to when i had my 20" tires on it. What do u guys think?

 

at $6 bucks from Rocky Mountain ATV, cant go wrong trying it.

rayz400ex
14t sprocket, s-bend, renthal bars
Honda 400EX RIDERS site:
http://home.elp.rr.com/hipo/atv/

 

I used a 12 tooth on mine and it worked really good just wheelied a lot but I didnt change size of tires. Just put on a 14 tooth to add some top end and it stills rides like a dream in the woods I also went down 2 teeth in the rear. I have a Raptor and wife the the 300ex and she got around better than myself but the trails were super tight could barely get into 2nd gear on either quad. I just have to get used to the raptor in the woods. later

 

I have 13T on the front of mine and there isn't much chain adjustment left. I'd be willing to bet you'll have to take a link or two out... or change your rear sprocket.