50 Tooth Sprocket

[SRigas]

Can I install a 50 tooth sprocket with the stock chain or will I have to increase the link number? I have a 2001 KDX 200 with stock sprocket and chain.:)

 

[Canadian Dave]

You'll need a longer chain, 110 links. The stock KDX200 chain won't outlast the rear tire, its not an o-ring chain, so you'll likely want to replace it in short order anyway. Ideally you'd replace the sprockets and chain at the same time so now would make sense while everything is still fresh.

If you want to test the new gearing out without the expense of a new chain and sprocket you can also install a 12 tooth front sprocket with the stock chain and rear sprocket. The ratio will be very close to the same.

David

 

[spanky250]

I run a 50 rear on my 250, and it is a definite improvement in power delivery over the stock 48. I don't know if the same problem occurs on the 200/220 as on my 250 when using the larger rear sprocket, but the increased diameter increased the rate of wear on the lower chain-guide block, I guess because of the sharper angle that the chain leaves the chain guide in route to the sprocket. Has anyone experienced this on a 200/220? I have found that the OEM blocks last many times longer than any of the aftermarket ones that I have tried.

 

[70 marlin]

slowed my 220 down to far.

all though it a better hill climber! and trail tractor!

 

[DJM67]

Perhaps ............

........ of interest to all the US and Canadian (and others on the site) riders.

The Australian version (street legal) of the KDX 200 came standard with a 14 - 45 sprocket set up. Damn fine commuting, but way too tall for serious off road stuff.

 

[snaggleXR4]

Hey,
You could go one tooth smaller on the front sprocket. It's cheaper, easier to swap back and forth and the change accounts for about 3 teeth on the rear sprocket. Finally it shouldn't make any difference with your chain guard. Good luck.

 

[Mike Hubert]

I could have done the math wrong but I figured 13/47 is the same as 14/51, I went with 14/50 for a little more carry for MX, I drop back to 13/50 for woods. My bike shop recommends against 12T because they feel it is too small and could contribute to a chain braking.

 

[BRush]

I have not really noticed much drop in top speed with the 13/50 setup. I was curious about the different gearing , so I did a little calculation. With a 13/47 (stock) setup, the overall drive ratio in 6th gear is 9.003; with 13/50 it's 9.577, and 9.753 for 12/47. For a relative (if idealized) comparison this would mean that at 6500 rpm, assuming a tire diameter of 26 inches, you'd theoretically see 55.8 mph with the 13/47, 52.5 mph with 13/50 and 51.2 with 12/47.

 

[70 marlin]

I went with a 13/50

and on the trails I was running 3/4 gears and lost a lot of speed on the top end. then I dropped back to a 14/50 and are now running 2/3 and have back all my top end? who wooda thunk?:silly: