plz help fast

[kyleschonert]

would 12/39 gearing be a good low end gearing combination for the 300EX. I race mostly mx at fair races, so the tracks are usually tiny. thanks.

[jwick07]

what ever the stock gearing is just go down one tooth on the front so if the stock is 14 go to a 13 tooth sprocket and that will give you better pull out of the corners but you will loose top speed, that is what many 450r riders/racers do and I like the change should work great for shorter style tracks with not to long of striaghts

[kyleschonert]

my dad was at our dealer today and asked them what we should do. And they said going down one tooth in the front is like going down 3 in the back. My stock is 38 so im gonna go with 13/40. I think if i did a 41 it would not have ne mid-top at all and id get passed. Thanks for the reply man.

[jwick07]

I dont know what your tire wheel combo is but I run eight inch rims with eighteen inch tires so this also changes gearing I loose top speed but get there quicker

[kyleschonert]

Ive got 9 inch rims and 18 inch tires. But im gettin 8inch rims and 18 inch tires. Its quick, but i cant go around the corners as fast as i should be able to.

[prepracing]

if u run a 12/39 with 18's your gonna be toping out at like 25mph:blah:

[kyleschonert]

thats why i said i would prob. go with a 13/40 or so:blah: that or a 13/39. or a 12/38.

[jwick07]

remember its only a 300ex not a lot of power and gearing may not be the only anwser. If you mess with it to much you will not be happy with the outcome. Try some motor mods, cam, carb, piston, air filter, jetting, rev box, and so on to get more pop out of the corners.

[kyleschonert]

im thinkin of gettin a cam and piston after this season's aren cross races are done. Im gonna tear it down and paint the frame, so i'll prob. do somethin with the motor.

[jwick07]

wow man just noticed but even a slip on with jetting will help a ton, better response and wake it up a bunch. I bought my HMF used and its great really helped first race with it I pulled the hole shot up of a second gear start

[kyleschonert]

My 300EX with my krome power pulled the hole shot against a 350X in a 300EX frame, blaster with a trenga built motor, another 300EX, and another blaster. But then i lose it all in the corners.

[jwick07]

axle and shocks then axlecaliber is really good and use body english

[bwamos]

Been a long time.. but I beleive the 13/38 is the stock gearing on a 300ex.

A 12/36 is about perfect for a stock bore 300ex with 18-20" tires. It's about half way between the 12/38 and the 13/38 stock.

13/38 = 0.3421
12/36 = 0.3333
12/38 = 0.3158

12/39 = 0.3077
Basically that along with 18" wheels will make you hit the rev limit.. 36% sooner. aka top speed will be 40mph ;) In other words you will be shifting a LOT!

I ran 12/36 on mine before I upgraded to a 330cc.
Now I run:
13/36 = 0.3611

[bradley300]

i would gear it taller than stock so you can just leave it in 1 or 2 gears so your not constantly shifting. only problem is you might need a littl motor work so you'l have the power there