Drag racing a KX 500 gears???

[wicked500]

hi I just bought a all stock 1987 KX 500 very well maintained bike runs hard!!! I want it to have a violent take off and to be very strong 1st through 3rd and pull monster wheelies and leave the 450f choking in my 2smoke oil burning fumes kxriders please help please suggest a front and rear combination for my 87 KX I'm looking for monsterous torque thanks guys

[wicked500]

other noob questions what the stock gear ratio set up i think i counted 16 teeth on the front sprocket not sure about the rear is my goal is to wheelie right by the brand new 450s and keep my bike pulling like a freight train

[KX500freak]

welcome !


what you want is both pull and speed,
i would change the 16T into a 15T.
and then get a 48T in the rear.

but its important that we know the current ratio ,
do you know whats in the rear ?

[Polar-Bus]

other noob questions what the stock gear ratio set up i think i counted 16 teeth on the front sprocket not sure about the rear is my goal is to wheelie right by the brand new 450s and keep my bike pulling like a freight train

If you have a 16T front sprocket, and you think your bike pulls hard now, wait till you gear it down a bit....  (14T is stock)

You will be horrified at the brute torque.....

remember gearing is a compramise, and based upon weather you want speed or acceleration..... you can't have both. As top speed increase, your acceleration decreases... and vice versa.

[Hillclimb#42]

Whats the Distance you are Dragging? 1/4 mile will be geared as high as possible. If its like 200 ft., it would be closer to stock gearing and launching in 2nd, IMO.
 

[wicked500]

we are dragging about 1/8 mile i went outside and looked at my bike it has a 16t front sprocket and a fancy looking rear aluminum sprocket and a serial number that ends and says 50t so im pretty sure i have a 16t front and a 50t rear im thinking about leaving the 50 in the rear and going with a 13t or 14t upfront whats your input? can i leave the same chain? it looks like a quality chain thank you for all the replies

[jfabmotorsports.com]

I always replace chain and sprockes together. 14/47=3.35:1  15/50=3.33:1 (my gearing...love it) and if I was lighter, Im 195lbs, I would try 16/50. 

[wicked500]

im 5'8 155lbs does that play into factor on how gear my bike? should i leave the 16t 50t combo thats on it? the combo i have what is that best for???

[jfabmotorsports.com]

LBS plays a huge part. I would try it. The front sprocket is the cheep one... change it first.

[wicked500]

should i go with a 13t front or a 14t front

[wicked500]

i forgot to ask can i get away with using the chain thats on it now?

[KX5Zuki]

What about an "override transmission"?? Full throttle shifts without the clutch, and no damage on the tranny gears? I would have made one by now, but I am still waiting on pics, etc. on how to do it. Nobody makes one for the KX500, just the drag quads that I know of. Anybody have any insight on this? The shift drum, and gears need to be modified, and heavier springs need to be added on the shift forks to make it possible.

Also, are the '86, '87, and newer transmissions the same? All interchangable parts?

[Hillclimb#42]

should i go with a 13t front or a 14t front

i forgot to ask can i get away with using the chain thats on it now?

If you are 16, now, I would step down to a 15 first. 15-50 is close to the stock gearing 14-47. 1/8 mile is still a good distance I think to be any lower. Definately try to be back in the adjusters as far as possible. If that means adding links or which sprocket/chain combo to use . One tooth on the countershaft roughly equals three on the back. And changing one on back is noticeable, so keep that in mind, too.
  I always pull 2nd wide open with the toe already under the shifter, when dragging. Try to get the tire to spin and then its a shiftin contest. We had good luck making the front wheel solid, with anything zip-tyed on the spokes. It helps to keep the staging lights broke, and therefore preventing a redlight.   

[oic0]

What about an "override transmission"?? Full throttle shifts without the clutch, and no damage on the tranny gears? I would have made one by now, but I am still waiting on pics, etc. on how to do it. Nobody makes one for the KX500, just the drag quads that I know of. Anybody have any insight on this? The shift drum, and gears need to be modified, and heavier springs need to be added on the shift forks to make it possible.

Also, are the '86, '87, and newer transmissions the same? All interchangable parts?

If I remember right, override transmissions blow up if you let off the gas while in gear. Great for draggin, horrible for everything else.

[wicked500]

next question Is it hard to change the front sprocket any special tools involved thank you for all the input