Sprocket choice. Need help

[EX_Junkie]

Ok i'm thinking the stock ones are 15-38 correct?

I'm looking for a little bit more bottom but i don't want to kill my top speed. Whats a good combo and can anyone tell me what kinda difference it will make off the line and what the top speed will be.

[cals400ex]

yes, thats the stock size for a 400ex. i don't know how big you can go on the rear sprocket with still having enough clearance to fit, but one or two teeth up in the rear will give more bottom end power. you could also go down one in the front (which is like 2.5 teeth in the rear) but your top speed will be slower. you won't lose a huge amount, but enough to notice for sure. by the way, going down in the front and up in the rear is the same thing which equals more bottom end power.

you could even get more technical and go down one in the front and down one or two in the back. this will both give more bottom end power than stock, but it also requires buying two new sprockets.

[Chanman420q]

if your ridn MX or have reaoly smooth tires id say 18 inch rear tires instead