Drive chain slack.

On the EK chain before it was changed out I noted that the slack, in some areas was 50mm and in others just over 30mm. Reasoned this was because of the inferior chain that Honda was recalling, and this was with only 300 miles of use. So the new chain, the DID is also breaking in with this same uneven measures. I'm measuring 35mm in some places in the chain and 50mm in others. I guess it could be sprocket related but in either case, take care and not adjust for the loose measurement if this is found on your NC chain. This could be one of the reasons for the vibrations some are feeling if the chain goes over-tight each revolution.

It does make measuring the slack more of a chore if like me you don't have a centerstand as yet.

Art

Are you taking the measure in the same location each time? If you are, I can't see a reason for the different results, even with a very bad chain

duk2n said:

Are you taking the measure in the same location each time? If you are, I can't see a reason for the different results, even with a very bad chain

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The chain is not stretching evenly, so if at one link you measure, say 30mm and you roll the chain 30 links and there you measure 50mm, and you adjust the chain at the 50mm link you will reduce the slack at the 30mm point to just 10mm, which is under the 30mm minimum that Honda says is needed for suspensiion movement.

Sorry if this sounds like I'm talking down to anyone, just trying to communicate.

Art

I check the play at two or three places and it never varies by more than a mm or two. Are you sure it varies 20 mm? Sounds like your method stops in gear or something and creates or releases slack in the bottom run of the chain.

It sounds very strange to me. Are you doing it in neutral?

Oldenuf is right, it's the same with me and i have a DID chain. If i spin the wheel with the bike on a stand i can see the chain going up and down, and i can measure 30 mm or 50 mm slack, depending what section of the chain is there. I suppose this is because it is new (less than 300 km as yet). I use Repsol chain spray as i always have.

Oh yes, and this could be why i get those vibrations, but not because of over tightness since the tightest it gets is 30mm. Which really is a false measurement because it is due to links not perfectly aligned. It would take much greater force than that a finger is capable of to straighten it out and get the real slack. Not much to worry about at this point, i think. I didn't change the slack, it is as came from the shop.

Funny though, that the manual says if the chain doesn't have the same slack at all points, it should be inspected. The Ténéré 660 manual, however, instructs the owner to search for the tightest point and measure the slack there. Quote :"The drive chain slack must be checked at the tightest point on the chain"

The only thing that can be worse than adjusting the chain slack on a Tén is measuring the engine oil level.

Looked up the Yam XJ6 manual and it's the same, quote :

"Move the rear wheel by pushing
the motorcycle to locate the tightest
portion of the drive chain, and
then measure the drive chain slack
as shown."

So i guess Yamaha takes a dimmer view of drive chains than Honda. Or uses inferior quality ones.

michaelks said:

Oldenuf is right, it's the same with me and i have a DID chain. If i spin the wheel with the bike on a stand i can see the chain going up and down, and i can measure 30 mm or 50 mm slack, depending what section of the chain is there. I suppose this is because it is new (less than 300 km as yet). I use Repsol chain spray as i always have.

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I hope you are right and the stretch will even out with more miles.

Art

I had wild variations in my chain with the recalled chain which I put off to the chain being bad. Since the replacement chain has less than 100 miles (all in one ride) I haven't rechecked it yet, but I will now. Most times you will find that chains have tighter spots and normally I set my slack at a tight spot. One thing I do is put the bike in gear and roll it backward (on a center stand just roll it backward) so that the chain is tight on top as if it was being driven by the motor. Check in lots of spots (a pain if your rolling the whole bike) and set to the tight spot. I guess this works well on street bikes, it was something I learned racing dirt bikes where the arc of the axle was high enough that the slack on top could really screw you up if you didn't take it out. I've been using this technique on street bikes for years with out any ill effects that I could tell. Then again I was told to adjust the chain loaded with riding weight by a street guy, didn't make since to me because the slack at the bottom is there to compensate for the arc of the swing arm and the variances there in. Otherwise all adjustments would be the same no matter the suspension travel, a bike with 14 inches of travel would have the same adjustment as a bike with 2 inches of travel and a swing arm half the length.

Cutter J. Duke said:

Then again I was told to adjust the chain loaded with riding weight by a street guy, didn't make since to me because the slack at the bottom is there to compensate for the arc of the swing arm and the variances there in. Otherwise all adjustments would be the same no matter the suspension travel, a bike with 14 inches of travel would have the same adjustment as a bike with 2 inches of travel and a swing arm half the length.

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It does make sense, only that what you have to check is if there still is slack when loaded (something like 10-20 mm), not the prescribed one. Ideally you should check if you still have slack when the sprocket, swingarm and wheel axles are aligned, which is the critical point.