We Walk You Through The Basics
Setting up the proper drive chain tension on your dirt bike is not a difficult task but it is a very important one when it comes to the proper care and maintenance of both your chain and the sprockets it rides on. A chain that is too loose creates problems as does one that is too tight so proper care and maintenance and regular checking s important. Performing a regular check and adjustment of your chain tension takes only minutes and can add miles and miles to the overall life of your chain and help minimize the chances of an on-trail problem.
The first step is to place the bike on a bike stand, centerstand or sidestand. Next with the rear wheel suspended off the ground put the bike into neutral and spin the rear wheel inspecting the chain for any rust, kinks or obvious problems and making sure it is spinning freely. Next go to the point midway between the front and rear sprockets and lift the chain up and down noting the amount of play (movement) from top to bottom. Normal play for a modern dirtbike is somewhere between 35-50mm of slack or 1.4 to 2 inches. If the chain slack is less than 35mm it needs to be loosened, it it is more than 50mm it needs to be tightened. Pretty simple.
To adjust the chain, with the bike still on the stand, loosen the rear axle nut but don't take it all the way off. Not all bikes are alike but they all feature some sort of chain adjuster bolts on each side of the swingarm that you turn to help move the rear wheel slightly forward or backward to adjust the amount of tension on the chain. This is the critical part, turn the bolts incrementally 1/4 to 1/2 turn at a time and be sure to alternate and do both sides equally or the wheel will not be positioned properly in the swingarm and the chain will be at an angle to the drive sprockets. Most motorcycles have some sort of notches or measurement markings on the swingarm to help guide you, just be sure that both sides are set to the same spot before tightening the axle bolt back down. Everything needs to remain lined up straight between the front and rear sprockets. Once you have the desired amount of slack in the chain and the chain adjusters in equal positions on both sides of the swingarm then just tighten the axle bolt back down to 65 foot lbs of torque or whatever the owners manual for your bike recommends and you are ready to ride.
Perform this quick and simple check every hundred miles, or better yet before every ride, and you will get maximum performance and life out of your drive chain and sprockets.
