Chain Adjustment

How tight should the chain be when it is not on the sidestand. I have adjusted it as per the updated Yamaha TSB. When it is upright with no rider it seems really tight. Less than 10mm of freeplay.

Is this normal? Does your bikes chain tighten when you lift it up?

Having owned this bike for a couple of years and playing around with different sprocket combinations I have found the best way to set the chain slack is to disconnect the rear shock linkage from the swing arm and then align the countershaft sprocket, swing arm pivot point, and rear sprocket in the straight line. This alignment gives you the longest distance between the c/s and rear sprockets.

Once you have this alignment (I use a strap around the seat to hold everything in place) I then set the chain tension so I have about 0.5" of travel at the center point of the chain when I push the chain up and down. When I have this I lock everything down, attach the shock linkage and then measure the free play with bike in the air and on the side stand so I have a number I can use without having to go through the whole procedure again.

In my case this happens to work out to be the same as taking my first 3 fingers on my hand and sticking them between the chain and the top of the chain slider. I am running 14/50 final drive on the bike.

motokid wrote:

Use this procedure.

Although I don't use the special force gauge thingy....

Just push up on chain with fingers.

Simple as that.

The image to the right shows measuring from the top of the chain link to the bottom of the swingarm for the 8-13mm.
Is this correct and I shouldn't be measuring from the center of the pin to the bottom of the swingarm?
Thanks!

Correct.

So I just adjusted the chain for the first time (new used bike) using this method and is it me or does this seem really tight?



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nowayout wrote:

So I just adjusted the chain for the first time (new used bike) using this method and is it me or does this seem really tight?

Tight? Are you sure you measured it correctly? When I did mine this spring, I measured 9mm of clearance and I found it was SUPER loose.
I tightened it up to 13mm of clearance this week after repairing a flat tire....

Would having WRX wheels on a WRR affect it?

nowayout wrote:

Would having WRX wheels on a WRR affect it?

No.

pretty new to my bike. just put on a 606. I have been stressing out about the chain adjustment. It seems awfully tight to me too.

05cr125r wrote:

pretty new to my bike. just put on a 606. I have been stressing out about the chain adjustment. It seems awfully tight to me too.

Here is a surefire way to give yourself some peace of mind. This works no matter what sprocket combo you have or what tires/wheels you have on. The chain is at its' tightest when the centres of rear sprocket, swing arm pivot, and front sprocket are in a straight line. You can achieve this by having your bike on a stand, unhooking linkage, and then jacking or lifting the rear tire until all three are in alignment. Then, adjust your chain to give yourself a bit of slack, and put everything back together. You now know that the chain will not ever be too tight as it swings through its arc. Put your bike on its side stand, and make of note of chain slackness from an easy reference point. From then on, you can tell at a glance, or a quick measure, when your bike is on the side stand, as to whether your chain needs adjustment.

Quick explanation, but hope it makes sense. Lots of stuff on youtube or google to show the above as well.

saddletramp wrote:

05cr125r wrote:

pretty new to my bike. just put on a 606. I have been stressing out about the chain adjustment. It seems awfully tight to me too.

Here is a surefire way to give yourself some peace of mind.  This works no matter what sprocket combo you have or what tires/wheels you have on.  The chain is at its' tightest when the centres of rear sprocket, swing arm pivot, and front sprocket are in a straight line.  You can achieve this by having your bike on a stand, unhooking linkage, and then jacking or lifting the rear tire until all three are in alignment.  Then, adjust your chain to give yourself a bit of slack, and put everything back together.  You now know that the chain will not ever be too tight as it swings through its arc.  Put your bike on its side stand, and make of note of chain slackness from an easy reference point.  From then on, you can tell at a glance, or a quick measure, when your bike is on the side stand, as to whether your chain needs adjustment.

Quick explanation, but hope it makes sense.  Lots of stuff on youtube or google to show the above as well.

Interesting insight, thanks. I'd add that it's generally better to have a dirt bike chain on the loose side rather than tight.

-morgan