13tooth frt sproket or 18's on rear, which rob's more topend

[MAD450r]

I was wondering if putting my 18's from my EX on my r would rob as much topend or less than getting a crf 13 tooth sproket up front ?

[ml450r]

A 13-38 gearing with 20's would be lower geared than a 14-38 with 18's. So your top speed shoudl be a little faster with 18" tires.
Merrill

[Matty24s]

I would think that you would do one or the other. when i put 18s on my 400ex i had to go up on my front sproket because it had no first gear to speak of. if you are doing 18s I would try that first before doing both.

[ho416mx]

I got my 450R yesterday & in my opionion if your going to leave the 20" wheels I would definately drop a tooth on the front sprocket. I also tried it out for a while with my 18's & I think that im still going to go up a tooth on the back sprocket. The bike is geared way too high from the factory, it doesnt have the greatest low end throttle response, but once you hit mid & top end it screams. My bike doesnt have the HRC kit, so maybe once the kit, or a aftermarket pipe is installed the low end should improve.

[MAD450r]

Thanks for your reply's guys, looks like i'll be sharing my 18's between my 400ex and my 450r then :)

[quadrcr161]

i put the 13 tooth on mine friday and im running 18inch turfs. i love it, saturday at the track i pulled side by side with a modded yfz off the gate going up hill. i cant wait till i get the cam put it. i could have had the hole shot but it was my first time lauching it hard on the track and first time riding it with the sproket change.