I had to do alot of research to find a 12T front sprocket since all of the familiar part numbers only go as low as 13T. So heres the list that will fit. Almost all brands have 2 that will work.

AFAM: #24502 and # 24501

Sprocket Specialists: #504K and #562

JT Sprockets: # JTF 516 and #JTF 512

Renthal: #260 and #280

I am 99.9 percent sure all the above will fit I have already fitted the AFAM 24502 13T and the Sprock. Spec. 562

 

I wouldn't go to a 12 tooth, the 13 is really pushing the limit. Remember the smaller the front sprocket the faster the chain guide is going to wear, and also the chain will wear faster since it will be going around a smaller sprocket. Just my 2 cents.

 

I agree, 13T is already kind of small. Figure out what ratio you really want and get the correct rear sprocket. Anything above a 13/50 just seems pointless....all the top gears will be too close together to be really useable. Most riders one here have moved towards a 13/45. But I could see, 13/47, 13/48 and even 13/50 as possiblites if you ride really tight stuff. Th estock KLX300R came with a 14/50 for general trail use.

 

With the 47T runs a little too tight on the rear chain guide, Im just worried about it getting caught and warping it. The reason I wan't this lower gearing is, I wan't a lower 3rd gear coming out of corners, and to be able to loft the front wheel easily in 4th. I know it's going to wear the chain fast but even good chains aren't really that expensive(under $100). I'm not worried about the the top gears I only use them in transit or high speed sandy road riding. I don't think I need to go any faster on the trails and roads then I have been. My goal is to be able to loft the front wheel going 50 or higher. I ride like I have a death wish so I need that extra umf for obsticles when nearing 60 on small spider trails.

 

i went to 13-48 on mine and it pulls really good in 3rd in the woods. i like to keep it 3rd or 4th
most of the time. one problem though. if you run the slack adjusters the way they should be,
the sprocket rubs the chain guide,so i left an extra link in and moved the wheel back. i am set
to 7 1/2 on the adjusters and doesnt leave much room for adjustment. i've ordered a moose
chain guide for klx300,kdx200 the same. hope it gives me more clearence so i can move it forward.
will have it in this week.

klx300
klx250s