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chain adjustment on or off a stand?
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socially distorted
Well-known member
should be done on a rear stand -- definitely not the side stand. Part of the chain adjustment process involves the entire rear wheel and axle sliding backwards incrementally [with the notches] and the notches on both sides must match up. If not, you'll have a tire thats not trued up or a tight spot in the chain. The rear tire needs to have nothing stopping it from moving, therefore the sidestand must be avoided. I'm no mechanic so if I'm wrong, I apologize, but I'm pretty sure I'm not.
Take your final measurements when the rear tire is on the ground though as the extra weight of the bike will tighten the chain up slightly.
I know you can do it on the side stand if you know exactly what your doing but it is much easier to do it with a rear stand.
I know you can do it on the side stand if you know exactly what your doing but it is much easier to do it with a rear stand.
RC-31
Well-known member
If you're adjusting the chain to get the correct chain tension, then you'll probably want the rear suspension COMPRESSED, not drooped. The goal is to make sure the chain is not too tight when the suspension has it pulled the tightest. The tightest the suspension can pull on the chain is when the centre of the front sprocket, swingarm pivot, and rear sprocket are all in a perfect line. With every bike I have seen, this point is somewhere between the loaded height and maximum compression. Put it on the centre stand, and tie up the rear suspension to raise the rear wheel. Either disconnect the shock(s) (so you're not fighting the spring(s)) or use a heavy duty ratcheting tie down to raise the wheel until the 3 points are aligned; then set the tension from there. You're looking for between 20-25mm.
It is true when suspension is compressed the chain tightens, but that method is going a little overboard on extra work as well as the factory manuals specs are not specified for that extreme, they are specified for just the bikes weight not the extra compression.
If you did adjust it to the specs with the rear compressed like that when you release it the chain will be too loose.
RC-31
Well-known member
It is not always true that the chain tightens. A lot of bikes once its passes a certain point (ie all lined up) the chain slackens again. Factory bike manuals outline an easy approximate way of doing it. It is not always the best. -- But they do know the behavior of their design. Remember the disagreement Ford and Firestone had over the handling of explorers ? That was the car company deciding what was best for the rubber, in the face of what the rubber manufacturer had to say. If you don't do it this way, then your chain will certainly be too tight at some times. Chain tension is supposed to be a maximum... not a middle ground or a minimum. Lots of people think that their chains are too loose, and some of them tighten them like guitar strings. Too tight a chain is putting wear on the countershaft bearing. A worn out countershaft bearing means cracking the motor apart to change it... at the least. ... And don't believe the standard line that all used bikes need the chains replaced for a safety. That's such a cash grab, like the "$800 Brake Job," or selling silicone spray at a shoe store.
I agree that too tight is bad. But how many shops around here if you were to ask for your chain tightened will ratchet your swing arm up or disconnect your shock? All that extra work is completely unnecessary unless you are a professional racer on a track bike and everything has to be perfect to shave those tenths of a sec off your time.
My 2 manuals say leave between 25-35mm of slack when the bike is on the side stand.
Also make sure to check it in more then one spot to make sure there are no tight spots.
The notches on neither of my bikes ever match. I look at the chain and see if it's straight or not.
Then something obviously isn't straight on your bike
Whether it be your chain, swing arm, tire alignment, axle... but something is off.
If your rear swing arm is angled down when on a stand, the chain will tighten when the weight of the bike is on the rear suspension and even more when the rider sits on it. (and even more is the rear sag is too much)
I like to check my chain tension with me sitting on the bike and target about 20-25mm movement. Chain tension doesn't matter when you are not on the bike, so why check it that way?
A chain that is too tight is not only hard on the counter shaft bearing, but ALSO CAN STOP YOUR REAR SWING ARM FROM MOVING.
I like to check my chain tension with me sitting on the bike and target about 20-25mm movement. Chain tension doesn't matter when you are not on the bike, so why check it that way?
A chain that is too tight is not only hard on the counter shaft bearing, but ALSO CAN STOP YOUR REAR SWING ARM FROM MOVING.
RC-31
Well-known member
You're right that NO SHOP is going to do this. That's one of the reasons that I don't trust shops to do anything. Disconnecting the shock or ratcheting the suspension down are just the P.C. ways of doing it. The truly easiest way to do this is to have one of your larger/heavier friends sit on it until it's at the right height, then check the slack. Your friend will not only be compressing the suspension, but will also be holding the bike upright for you, too. @ Franko! : Excellent point !! I've witnessed that 2nd hand.
I check it while Im not on the bike because my suspension is set correct for my weight. So when I set it to the 25-35mm without me sitting on it I know it will be right for me once I'm sitting on it.
But to all their own, I was just pointing out the easiest and most common way of adjusting it.
jefflthomas
Active member
on the side-stand mate
Though you have an understanding of the main points, you are totally mis-understanding the OEM spec.
IF the bikes shop manual calls for 20-25mm of slack, then adjusting it your way, and using the same spec of 20-25mm will result in a very sloppy chain - and pointless extra work.
Exactly!
few things wrong here again. To clarify - there is no such thing as chain tension. You don't set chain tension - chain tension is ZERO.
You set the chain SLACK.
And no, if you set the chain slack according to the OEM specs, you will certainly not have tight spots at times.
The OEM spec fully compensates for the full swing of the swingarm, and is the correct measurement.
You mentioned the ford VS firestone tire pressure setting..... how does that apply in this case? This is the OEM spec VS __________"your opinion"?
Lastly, if you did adjust your chain by first lining up the three points (sprockets + swingarm pivot) you could set the slack to any positive number, and the chain will then never be too tight. Even 1mm of slack when the suspension is compressed to it's aligned position would be enough to guarantee you never ever have a tight chain through the full swing of the swingarm.
If you then lock it all down "tighten the axle", and let the bike's suspension relax - your chain will then have enough slack.
Why bother going against the OEM spec?
Not sure why either, but, in that case, Ford was telling customers to run a very low tire pressure to compensate for having a heavy tire that rode rough at a "normal" pressure. In this case, OEM was wrong. Very wrong, and I still do not understand how they managed to put the blame on Firestone.
RC-31
Well-known member
Quite right on my misuse of the term tension. I would have meant to use the word "sag." You're also right that using the sag spec in the bikes manual to the method I presented would (probably but not necessarily,) result in far too much sag. But the specification to use to set the sag would not come from the bike's manual, but rather the chain manufacturer's own specs. I somehow assumed (and wrongfully, too I guess,) that it was for a replacement chain, which would have had the sag specifications on the box. DID recommends between 20-25 mm measured like in this diagram: http://www.sprocketcenter.com/UserFiles/486-Files/Image/D.I.D. Sag Pic.gif 3/4" is ~19mm. Why would it matter if it's a replacement chain ? Because you'd notice a difference in the instructions between the chain's makers instructions and those in the bike manual. The chain manufacturer doesn't know what kind of bike you're installing it on, so they show you the universal way of doing it. The bike maker comes up with an easier way for you to do it, usually with a special tool in the kit and a mark somewhere on the swingarm. If you change the height of the rear suspension, though... those specs might be out the window. A lot of people install lowering links, have adjustable length shocks, or have other ride height adjustments like pulling the fork tube up the yoke; all which will have an effect on the swingarm angle if the bike is sitting on the side stand while being measured.
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