Desert Gearing

[HBRider]

I need help with gearing my bike for the Dez. My bike is a 1999 250MXC with 13/52 stock gearing and a 116-link chain.

I want to run a 13/48 or 13/50 and need to know how many links to drop in order to run the 48 or 50 tooth sprockets. Can I get away with the stock length chain or change the front sprocket to a 14tooth????

I am trying to gain more overall speed(as I am always looking for sixth gear) and would like a lot more speed when I first jump on the throttle.


Thanks

 

[YZ165]

I am trying to gain more overall speed(as I am always looking for sixth gear) and would like a lot more speed when I first jump on the throttle.

That's a contradiction HBR. You can have one but not the other. More top speed = slower acceleration and less top speed = faster acceleration.

Try a 14t front sprocket first, and see if that is enough gear for your needs. If not, start droping the rear.

A general rule of thumb is 1 tooth added to the front is the same as taking three off the rear.

As far as chain length goes, you can usually get away with changing the front up or down one tooth with the stock length chain. You may need to add or remove two links to change the rear sprocket two teeth up or down. But, it's best to pick the gearing you want, and then cut the chain to the proper length.

Hope that helps, YZ165

 

[Rod.S]

Gear ratios

YZ165 is absolutely right, if it fits OK, going to a 14 tooth front sprocket will increase top speed by about 6%, say 100kph to 106 kph max. The loss in bottom end pick up is almost un-noticable due to wheelspin etc. in first gear.

Additionally the extra cost of a 14tooth front is much less than a new 48 tooth rear and as he says the same drive chain will be fine.

I recently did exactly this to my Gasgas 400 Supermoto and is performs much better in terms of top speed quietness and without noticable loss of bottom end acceleration.

Good luck
Rod

 

[HBRider]

Thanks for the replies folks, I appreciate it. :cool:
I now realize you cant have it both ways so I decided to go with 13/48 gearing and a 112 link chain. I needed to gain more top speed so this seemed to be the best route. My chain and sprockets were already worn so I had to make the investment anyway.

I asked a few mechanics about the number of links vs teeth and was told that for every 1-tooth added, you add 1 link. For every tooth dropped, you remove 1 link. He said every bike varies and like YZ165 stated you can get away with the stock chain if you only go 1 tooth up or down.

Rob