I checked my rear sproket last night when I removed the wheel to mount a new tire. My dealer told me that it was supposed to be a 48 tooth but it is stamped as a 50 tooth. How much more torque will I get with a 52 tooth which seems to be the biggest I can find for my 99.

Bonzai.... :)

Torque is in the eye of the beholder, as are most mods :). The benefits are two fold if you keep the stock chain length ie lower final drive ratio and you move the rear wheel up, shortening the wheelbase for sharper/easier turning.

If you want to gear even lower, go with the 13T countershaft sprocket.



99 WR400f, YZ timed, MX-Tech suspension, Scotts steering damper, White Bros E-Series (12 discs), tapered header and a/f. Kouba T-handle for the fuel screw. Works Connection billet throttle tube and frame guards. Cycra Pro-Bend, triple clamp mount handguards. Thumper Racing rad guards, Renthal Jimmy Button highs, YZ Tank and IMS seat, YZ number plate, odo removed, de-octopussed (Thanks Clark) EKP #4, 50PJ, 175MJ, 100PAJ and 65 SJ at 500-1000' Thanks James Dean!

changing the teeth on sprockets just shifts the power relative to speed/engine RPM.


'99 WZ/YR (you choose!) with ALL YZ mods, de-octopused, DSP Doug Henry airbox w/ velocity stack, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, OEM YZ tank, IMS YZ seat.

In the simplest terms and the only terms I know, If you go to a 52 tooth sprocket af few things will happen.

1. Better pull coming out of the corners.

2. Easier loft of the front. Great for trails and logs.

3. If you find yourself stuck in between 1st and 2nd or 2nd and 3rd on the trails or the track, it will help you stay in 2nd or 3rd with less bog and more power when you need it. Thie results in less shifting back and forth.

4. To me anyways, it made the bike feel lighter with the improved snap.

I also found it to be good on the track, allowing me to ride in 3rd gear most the time. I think if you try it, you wont be dissapointed at all. If you dont like it, I will buy the 52 tooth sprocket from you since I am getting ready for new chain and sprocket. My bike came stock with a 50 tooth sprocket. My friends 99 had a 50t and he went to a 52 and loved it as well. If you kept the 50 on the rear and went to the 13 in the front (countershaft) sprocket the results would be similar, a little more torque. I would give the 52t a shot. This is mostle relative to track and trail. If you are hauling ass ascross the desert with a 52t rear sprocket, you bill be looking for more speed than torque. The 48 may work for you in that way.


Funny...I went to a 49T from a 50T to get a little less "activity" at higher speeds. I dual-sport my WR and I found myself always reaching for that non-existent 6th gear. I didn't want to compromise off-road ability so I went only one tooth smaller on the rear. It definitely seemed less snappy at first, but I've gotten used to it. What it has given me, though, is a lot more traction. Since the rear wheel isn't as prone to break loose, I get more traction. What's surprising is that I find myself riding one gear lower off-road than I used to. This keeps the motor higher up in the power band for a lot more useable power. The smaller rear sprocket enables me to do this without revving it too high all the time. The downside to this is that since I'm running one gear lower, my gas mileage has dropped a little to around 30 mpg.

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