Dirt bike question about chain tension?

Question

my ttr 125 le has a fairly loose chain with about 3 inches of sag. i need to know if i need to put the bike up on a stand to tighten the chain or can i just do it while its on the ground. ive never had to do this before. also is it an easy task?

thanks

Answer 1

It is best to loosen the axle nut before raising it, I use an car axle stand under the frame, you can also use a wooden block (these are less stable). Before you start adjusting the chain though release the brake actuating rod, marking where it was adjusted to before you remove the wing-nut (a bit of masking tape is handy for this). Raise the bike on the stand, release the axle nut further, adjust the snail adjusters on each side. It is important that you keep them aligned otherwise the wheel will not be inline with the front, you cannot necessarily rely on the markings on the adjusters.

After the adjustment lower it to the ground check the vertical movement of the chain at the midpoint between sprockets, you should have 40mm of movement, significantly more or less and you will have to change the adjusters. Once you have completed the checking you need to check the alignment use two parallel planks either side of the wheels, make certain it is aligned and tighten the axle nut, it is important to not tighten them too tight as the bolt will begin to microscopically stretch, your owner manual will give you the torque reading required. If you do not have a torque wrench borrow one or buy a cheap one, you will need one for other jobs. Once tightened reattach the brake actuator and adjust it.

It isn't difficult and shouldn't take too long, but is worth taking time over as mistakes can be painful.

Answer 2

different bikes need a different amount of sag buy a manual  

Answer 3

it would be easier to do if on stand or block but you dont have to you need about a inch.. loosen back wheel nut adjust one turn each side and retighten wheel nut too tight is just as bad

Answer 4

put it on centre stand with the back wheel off the ground. The tension is right when you can get two fingers in between the chain guide on the swingarm and the chain.