Chain slack confusion

[Oxxa]

Today I decided to set my bikes chain slack but I am very confused about the process. All the different tutorials and manuals state different things.

 

1. From which point of contact of the chain guard plastic to measure the starting point from? The plastic itself has 3 levels of height from front to back.

 

2. Should I press down on the chain and then measure? If so, how hard do I press down? Should I hold it down? Or just press once and let go?

 

3. How important is the wheel alignment precision? Should I worry about it on a micrometer level or a milimeter level?

 

4. Side stand or center stand? I cant always remove all my luggage and protectors to set chain slack as instructed in the owner’s manual.

 

I tried all of the options and all of them are very different from each other.

 

 

[S.Ga.Rider]

2 hours ago, Oxxa said:

Today I decided to set my bikes chain slack but I am very confused about the process. All the different tutorials and manuals state different things.

 

1. From which point of contact of the chain guard plastic to measure the starting point from? The plastic itself has 3 levels of height from front to back.

I use the back of the plastic to measure from, the thinnest part.

 

2. Should I press down on the chain and then measure? If so, how hard do I press down? Should I hold it down? Or just press once and let go?

Press down on the chain with medium tension, then push it up and get your measurement. 

 

3. How important is the wheel alignment precision? Should I worry about it on a micrometer level or a milimeter level?

The marks on the axle adjusters are fine. 

 

4. Side stand or center stand? I cant always remove all my luggage and protectors to set chain slack as instructed in the owner’s manual.

Side stand.

I tried all of the options and all of them are very different from each other.

Its better to be a little lose than too tight.

 

 

[Uncle M]

@Oxxa here are the thorough instructions from the service manual. With bike in neutral and on sidestand, measure from the bottom of the back end of the guide "rib" to the center of the chain rivets.

There's very little that's confusing if you consult the service manual! It's available here and I believe somewhere on this site for free download too. Hope this helps!

Edited October 27, 2022 by Uncle M

[Chris1974]

The only thing that is not specified is how much pressure you need to put on the chain to measure the slack. This can make a big difference... 

[Oxxa]

7 hours ago, Uncle M said:

@Oxxa here are the thorough instructions from the service manual. With bike in neutral and on sidestand, measure from the bottom of the back end of the guide "rib" to the center of the chain rivets.

There's very little that's confusing if you consult the service manual! It's available here and I believe somewhere on this site for free download too. Hope this helps!

i have already read the manual but my confusion remained because it doesnt specify if from the middle or the bottom of the chain guide since the chain guide has levels of height you can see in this reply’s attachment.

[Oxxa]

41 minutes ago, Chris1974 said:

The only thing that is not specified is how much pressure you need to put on the chain to measure the slack. This can make a big difference... 

exactly, that makes a 5mm difference.

[Tenerider]

Following hints from other guys here, I once adjusted chain tension on the sidestand (this is what the manual says). Then I put her onto the center stand, and took a measurement just as shown in the service manual.

The distance was roughly 5mm more - so my goal for center stand chain distance is 50mm (lower end of the plastic chain glider to middle (!!!) of the chain).

 

I'm not pushing the chain down as hard that my fingers hurt, but I definitely give it some proper tension.

[Mr. Kwak]

7 hours ago, Uncle M said:

@Oxxa here are the thorough instructions from the service manual. With bike in neutral and on sidestand, measure from the bottom of the back end of the guide "rib" to the center of the chain rivets.

There's very little that's confusing if you consult the service manual! It's available here and I believe somewhere on this site for free download too. Hope this helps!

 

Well Yamaha did update the manual. (didn't know that)

 

In the 2021 manual it wasn't clear which part of the drive chain guard should be taken for measurement. Can relate to this tread because the guard is 5mm high and that is the same as the slack. If you took the wrong point on the chain you would always be wrong. 

 

See attached below the 2021 manual. (Point 4)

[Oxxa]

18 minutes ago, Tenerider said:

Following hints from other guys here, I once adjusted chain tension on the sidestand (this is what the manual says). Then I put her onto the center stand, and took a measurement just as shown in the service manual.

The distance was roughly 5mm more - so my goal for center stand chain distance is 50mm (lower end of the plastic chain glider to middle (!!!) of the chain).

 

I'm not pushing the chain down as hard that my fingers hurt, but I definitely give it some proper tension.

I have 5mm difference sidestand/centerstand too so I guess that’s confirmed.

 

Are we sure point A is the lower end of the plastic chain glider?

[Dougie]

If you downloaded the manual, from here, and print it, it’s not confusing, it is clearer where the datum is, (after zooming in with the phone as I’m over 40. You could just print the page you need. Or print the hundreds of sheets at work.

Edited October 28, 2022 by Dougie

[Uncle M]

7 hours ago, Oxxa said:

 

 

Are we sure point A is the lower end of the plastic chain glider?

Correct, zoom in on the manual's diagram. Point A is the lower edge of the "rib" of the plastic guide, at the end of the guide closest to the rear axle. I guess you could ask your dealer, or someone you know who has experience with doing their own maintenance, to show you how much pressure to use to push the chain down.