Chain Alignment

[salty_monk]

Anyone have a good trick for measuring alignment of the chain (front to back in the horizontal plane).

Currently I've done it by clamping a straight edge to the rear sprocket, just wondered if there was another way.

Also - might be a silly question but what is an acceptable tolerance?
For example will the chain put up with being run with one sprocket 1mm further over than the other? There must be some tolerance when measuring....

Dan

[posplayr]

Anyone have a good trick for measuring alignment of the chain (front to back in the horizontal plane).

Currently I've done it by clamping a straight edge to the rear sprocket, just wondered if there was another way.

Also - might be a silly question but what is an acceptable tolerance?
For example will the chain put up with being run with one sprocket 1mm further over than the other? There must be some tolerance when measuring....

Dan

It needs to be perfect





Having been through recently as well. I would say 1mm is a good objective if you can get it. 5 mm is too much. Never go more than 1/2 a sproket tooth width unless you want the chain to hop off.

Since the sprocket carrier is mounted in rubber, and there can be significant errors bolting small lasers to the sprocket, I think that making sure the chain is parallel with the wheel or maybe even the tire is (albiet indirect) is a good way to confirm the alignment.

see my install notes and attached pic here.

http://www.thegsresources.com/_forum/showpost.php?p=1083231&postcount=146

[mighty13d]

so just cranking until "this looks about right" isn't the correct way?

[Steve]

Anyone have a good trick for measuring alignment of the chain (front to back in the horizontal plane).

Since the only chain in my GSs is the CAM chain, there is no problem.

I will happily put up with my heavy, quiet, clean shaft drive and leave now.

.

[BassCliff]

Hi,

The "eyeball" method works pretty well. Look up the chain from the rear wheel. Make sure the front/rear sprocket teeth are centered in all the links as the assembly rotates.


Thank you for your indulgence,

BassCliff

[Agemax]

a small amount of misalignment is perfectly ok. the chain itself, even brand new has a certain amount of lateral play.
it will not jump the sprockets unless the rear wheel is not lined up correctly

[salty_monk]

I'm still going for the 5.5" wheel & 170 tyre. Funny thing is, after really struggling to find one I now have 2 of the 4.5" wheels.. so I have a backup if I can't make this work out.

Anyone have a good source for 520 offset sprockets in case I need to go that route?

Dan

[salty_monk]

Pos so you have approx 2mm of offset between front & back sprocket.

520 is 6mm (1/4") wide so I guess 2/3mm should be ok. I believe I can easily get within that sort of tolerance.

Dan

[posplayr]

Pos so you have approx 2mm of offset between front & back sprocket.

520 is 6mm (1/4") wide so I guess 2/3mm should be ok. I believe I can easily get within that sort of tolerance.

Dan

I would try not to be at 3mm, that would be the worst case for preventing throwing a chain. It says nothing about chain wear.

I'm using a 530 which is a little wider. I also have more hp though so there are other considerations.

[jpaul]

I used to just eyeball it, looking down the chain from the rear sprocket to the front. Then someone gave me a laser level to use for hanging pictures. It has two pins that come out the bottom, to stick into the wall, and then it projects a nice straight line. By setting the pins on the inside edge of the chain sidewalls, it projects the line right down the chain. It turns out that my alignment wasn't any better than carefully eyeballing it, but it was nice to get confirmation. Plus, my eyesight isn't getting better as the years pass.

[tone]

Since the sprocket carrier is mounted in rubber, and there can be significant errors bolting small lasers to the sprocket

Incorrect ! the rubber has no effect on sprocket alignment it is only a damper that is allowed to work/move in the direction of wheel travel & back & once bolted into a swingarm can NOT move in any other direction

If yours moves in any other way apart from the direction of wheel travel & back you have messed up probably the carrier spacer !

Back to the job at hand the chain will move around 1mm side to side on the sprockets this is to allow for small variations in alignment when ajusting the chain using the inacurate swingarm marks & to avoid stiction/friction between the moving parts, any more misalignment than that will cause more chain & sprocket wear, rob a small amount of power, cause vibration & be noisy

Get it 100% spot on to avoid problems mate

[salty_monk]

Going to do my best... worse case I'll revert back to the 160 tyre on the 4.5" wheel & sell the 5.5" with the 170 on...

Time to try to take some more measurements - it's not easy!

[posplayr]

Incorrect ! the rubber has no effect on sprocket alignment it is only a damper that is allowed to work/move in the direction of wheel travel & back & once bolted into a swingarm can NOT move in any other direction

If yours moves in any other way apart from the direction of wheel travel & back you have messed up probably the carrier spacer !

Back to the job at hand the chain will move around 1mm side to side on the sprockets this is to allow for small variations in alignment when ajusting the chain using the inacurate swingarm marks & to avoid stiction/friction between the moving parts, any more misalignment than that will cause more chain & sprocket wear, rob a small amount of power, cause vibration & be noisy

Get it 100% spot on to avoid problems mate

Well I might have oversimplified the statement but the conclusion is the same. The fact of the matter is that the alignment and wobble of the carrier is largely determined by the tolerances of the single bearing contained in the sprocket carrier. From what I have seen typical tolerances are between 0.005 to 0.010" of an inch just between an axle and the inner race bearing. The outer race also moves with respect to the inner race. Give it another 0.005 for arguments sake. I don't have the measurements in front of me, but these same types of errors also exist for the wheel bearings but the wheel bearings are spaced by some 8" or so v.s. the carrier bearing slop acting at a much smaller distance (0.8" for the inner race to axle). That is 10 times the angular error in the carrier v.s. the wheel for misalignment due to bearing to axle clearance.

So granted it might not be obvious but because the carrier has rubber bumpers, that allows a single bearing to be used on the carrier which allows more angular deviation that if the carrier were literally bolted to the wheel and the angular misalignments were only attributable to bearing errors.

I could be proven wrong, but this is the distinct impression I got trying to bolting a laser to the sprocket. I know for a fact that the sprocket walks all over when the axle is not bolted tight. This in and of itself suggests that the trueness of the sprocket is based on how perfectly square the spacers are that form the load path through the wheel bearings between the swing arm forks. Again this is because the sprocket carrier are transmitted through rubber and there is no machined surface attachment at any radius equivalent to the sprocket OD.

Of course what I could do is a run out test of the sprocket as compared to the wheel and adjust for the radius difference to compare angular tolerance of wheel v.s. sprocket. Not sure when I will get a chance (unless someone else wants to confirm) Dan??? how about you? you started this after all.

Get it 100% spot on to avoid problems mate

BTW there is no such thing as 100% ; that is an illusion as nothing is perfect and errors manifest themselves in many different ways and have differing effects. In the case of alignments, angular errors typical manifest themselves as either run out of offsets based on the lever arm they operate through.

[tone]

Pos thats another blah blah post full of "facts" & figures that have no bearing on reality while it may baffle the unwary i'm sorry but i'm not impressed or convinced

If the bearings are in good condition the correct spacer is used & the SPINDLE (axles are on cars ) is tight the sprocket carrier will NOT move in any other plane than that in which it was designed to move.

Trying to measure any runout with the spindle loose as you suggest is pointless as it was NOT designed to run that way, any runout or movement found with the spindle tight is indicitive of a problem

tone

[posplayr]

Pos thats another blah blah post full of "facts" & figures that have no bearing on reality while it may baffle the unwary i'm sorry but i'm not impressed or convinced
tone

Sorry if you thought the purpose was to baffle or impress the unwary especially yourself. I truely am trying to speak at a level consistent with the forum.

It is however very apparent that any analytic approach to tolerance analysis is falling on deaf ears. I can only gather that in your many years of learning, and practicing the "art of motorcycle alignment" the very real issue of measurement uncertainty and mechanical tolerances has never become obvious to you.