sprocket question

[njkx]

i have an 01 kx 250 with the stock sprocket 48T i think. i need a new one and am looking for more bottom end power. that means bigger sprocket right?? should i go with 49 or 50? how much difference does 1 tooth make??

 

[WaltCMoto]

I went from a 13-48 to a 13-50 for same reasons as you. The 2 tooth differance is a noticeable change. Im glad I went for 2 instead of 1

 

[RAH RAH]

a cheap way to check that out is to drop one on the countershaft sprocket. 1 on the front is equal to about 3.5 on the rear. Keep that in mind when deciding on your next set.

 

[kawdude]

If you drop on the countershaft size pay attention to see if the chain hits the case.

 

[FSracing]

i recently changed for a 49 tooth...i have a kx 250 01 and i mostly ride trails...

I am really happy with my new spocket.. our bike has a really strong bottom end... if i had picked higher than 49 i 'd ride mostly 5th gear even in some tight trails...and the lack of top end i guess would be too much felt... ( at least you ride really really tight stuff all the time i'd go with higher than 49 tooth)

By the way i put a 11oz flywheel at the same time i changed my spocket... so my observations are based on that mod too...which may not help you that much...

 

[Jaybird]

Actually, going to a 12t CS will net you a 4:1 ratio when using a 48t rear. The very same ratio would be obtained by going to a 52t rear (4 tooth change)and keeping the 13t up front. The change of ratio when changing the front is relative to what rear you are using.

Not only can going smaller find clearance problems, it will accelerate the wear that your chain sees.
I always suggest folks go larger on the rear if at all possible. You also have to be aware that going too big on the rear can also cause clearance problems on some bikes.

I think you will find what you are looking for by going 2 more on the rear. If you were riding a 125, I'd suggest 4 more.

Note that you will also be needing a longer chain if you go 4 more on the rear.

LOL...decisions, decisions!

 

[njkx]

thanks guys...i think i'll just go to 50 on the rear and keep the front the same. Not looking for anything drastic, just a little quicker response coming out of corners...i'm having to do too much clutch work now and can't get into the powerband in 3rd quick enough to set up for certain jumps.

 

[glx1747]

I just went from a 13t front and 50t rear, to a 52t rear. It has a little more response on the low end, but your top end will severely decrease! My bike is geared so low now that my 2nd and 3rd gear are almost the same. I would recommend just moving up to a 50, and the next time you have to get new sprokets try another size bigger. I said all of that to say, just experiment.

 

[SamMiDD]

I only go 1 tooth up to start with i find 2 teeth to much of a difference in one go but i am talking 125's here mayb on a 250 you can hold gears longer and get away with it a little more

 

[Porstala F9]

I bought a 12 tooth sprocket, and I didnt use it yet because I am told it will wear down my chain fast..

 

[500_boy]

On my 85 CR500, I was told a 14 oz. flywheel weight would make it a more manageable bike through the trails, but I really love that feeling of mid-top power, so would getting a sprocket that say is mabye 2 teeth less than stock give me this, because as of now the bottom end on the bike is crazy, and I am putting an FMF Knarly Pipe on it which is the only aftermarket pipe I can get but it is for bottom end mostly. So would 2 teeth less on the rear sprocket even this out and give me the mid-top power I want?