Drive Chain Adjustment

[chasp72]

Hi all,
I've got a newbie question. Could someone help me with an interpretation of chain slack? The manual says the drive chain slack should be 5-15 mm (0.2-0.6 in). Is this tested by pulling a tight chain down and then pushing it up with some force and measuring the travel distiance? Or am I looking for the measurement of a chain that hangs a little loose on the bottom so it easily moves up and down? I hope this makes sense.
Thanks.

[jonathan180iq]

What you are asking is essentially the same question.

The amount of slack the chain has is the distance between the highest point and the lowest point of chain travel, when lifted up or pressed down. The difference should be no more than 15mm and no less than 5mm.

Look at the chain as it rests. Lightly press down from the center (where the chain hangs the lowest) and take note of what number your measuring device reads from the bottom of the chain. Write that number down. Now, with the measuring device still in place, lightly lift the chain to the top of its travel and make a note of the reading,also from the bottom of the chain. Measuring from the top will give you inaccurate readings. Then, subtract to find the difference and adjust as necessary.


hope this helps,
Jonathan

[Badbob]

To add to what Johnathan said:

You need to do this at the tightest point on the chain. With the bike in neutral and the rear wheel off the ground slowly turn the rear wheel while moving the chain up and down at the bottom center until you find the tightest spot. Make you adjustment here. If you were to make the adjustment at the loosest point the chain will be to tight when it comes around to the tightest point. Possibly tight enough to damage the bike.

Make sure you adjust in small increments and turn both adjuster the same a mount. I usually move them only 1/4 turn on each side. This will help keep the sprockets aligned properly.

Note that on some bikes the marks on the adjusters are incorrect. I have one of these. In this case you will need some sort of straight edge to get it aligned properly. I bought an chain alignment tool but there are ways to do this using a piece of string or a ruler. The alignment tool just makes it easy.

[chasp72]

Thanks for the info. I'm going to recheck this before riding this weekend.