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Chain alignment

5K views 33 replies 18 participants last post by  BravoFox 
#1 ·
Is a laser tool any good when aligning the chain and rear wheel, I was thinking of buying one.

Plasma1
 
#17 ·
If you're out, you'll know.

Typically I check this if I take the wheel(s) off, or the simple adjustments are true but I feel disturbances in the ride.



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#18 ·
I made my own with a laser key chain a bit of cardboard.
I placed the laser on a flat surface and rotated it until the beam went perfectly parallel with the surface.


I now just place it on the chain wheel and make sure the laser points to the same place on the chain throughout it's length.


Total cost €1. HA!
 
#19 ·
Is a laser tool any good when aligning the chain and rear wheel, I was thinking of buying one.
I bought a Profi dot laser not long ago to replace my rod type chain tool because the rod had bent. I would not go back to any other chain alignment method now. What many folk are not realising with chain alignment is that it does not involve the front wheel. The only way that the front wheel can go out of alignment is if the forks or frame are bent, then it will go vertically. This is a different thing than the handlebars being out of alignment with the front wheel. The front wheel cannot go out of alignment with the frame horizontally, since the handlebars, and you, will automatically compensate. Chain alignment aligns the chain with the sprockets to reduce wear. Rear wheel alignment is a secondary by product of this, since again if the rear wheel is slightly out of alignment the rider and steering automatically compensate.

Go ahead and buy the laser tool, you will find that it makes chain alignment a breeze and you can do it without having to remove anything.
 
#21 ·
I had a Yamaha XS-1B that would always "turn" if one just sat straight and rode with no handlebar pressure. I always attributed it to me having uneven weight on the saddle due to bad hips. But my TB tracks true. So maybe the Yamaha always had a misaligned front/rear wheel. I checked the rear wheel and chain alignment to the frame, but never the front.
 
#22 ·
To align everything this is the procedure I use. It works to make your bike track straight. 1) adjust the chain so that your sprocket are aligned. You should be able to spin your rear wheel and note that the rear sprocket has an even space on each side and looks straight with the front sprocket. 2) Measure from center of swing arm pivot on both sides to center of axle. It should be pretty even, if not, even it up and see if the chain is still looking straight. 3) Adjust both sides evenly to get proper chain slack. 4) go to a dirt road and gas it hard in first gear from a roll. If the rear end walks right, adjust the wheel so it is pointed a hair more left, then get chain slack correct by doing both sides evenly. This way the bike always launches and goes and stops straight. If I recheck at this point it's so close you can't tell, and the wheels are aligned when rolling down the road.
 
#24 ·
It takes pretty fine adjustments to get the chain aligned with the sprockets, using the lasers or the rod-tools. You can do it pretty exactly. I couldn't be nearly that accurate measuring from the swing arm pivot to the axle with a cloth tape myself. Then again, I don't know if that level is precision is necessary, or if aligning with the chain is the "right" alignment. Pretty sure it's good enough though. Actually, pretty sure the cloth tape thing is good enough too.
 
#25 ·
Then again, I don't know if that level is precision is necessary, or if aligning with the chain is the "right" alignment. Pretty sure it's good enough though. Actually, pretty sure the cloth tape thing is good enough too.
The level of accuracy with a laser isn't neccessary but the more accurate you can be, the less chain and sprocket wear you will get. Wheel alignment (rear) doesn't really come into it, because the bike is specifically designed and made so that the rear spindle will be at 90 degrees to the centre line of the bike when the sprockets are exactly in line. The tape measure is good enough and so is the rod tool, its just that the laser is not only as accurate as you can get, but less hassle in doing the job.
 
#26 ·
Straight as can be

Don't worry about your chain alignment, worry about your tires pointing crooked. The alignment marks on the swing arm are not very precise in many cases. I have seen some that are way off.
What you perceive as a straight chain may or may not be precise enough five feet away at the front tire! Even with a laser you are measuring the wrong thing and not including the parts that are affected---THE TIRES!
But unless your rear swing arm is actually bent your chain and sprockets will track correctly ONCE your tires are not tracking crooked. This assumes your wheels are not bent which is another subject altogether. So do your tires and then everything else will be true unless something is wrecked.
So how can you check to see your TIRES are tracking perfectly AT THE TIRE?
Your tires will track correctly when they both are pointed the same direction and the rear is centered in the footprint of the front. If your tires are pointed crooked by even a little bit the bike will feel wobbly.
The basic way to check is to get two eight foot long florescent light tubes and lay them against the left and right sides of your rear tire face. These are manufactured to be as straight as can be. They will show which way your tires point at the same time together compared one to the other.
If your rear tire is the larger of the two then the front tire will be sitting inside the tubes and pointing exactly the same direction the rear is pointed. If the rear tire is crooked then the tubes will be on one side or the other but NOT equally centered. This means the rear tire is NOT pointing the same direction the front tire is pointing. Can you visualize this idea?
Now. I do NOT use light-bulbs to align my tires as they would last five minutes in my shop before being shattered. I use a string as has been pointed out before. Others may use two eight foot long straight edge rulers but these are pretty expensive if you are a do-it-yourself shop. As I only do this procedure once a year or with tire changes I am too cheap for that route.
You place a very long string on your rear tire at the back and stick it there five inches or so off the ground using a piece of masking tape to hold it for a minute.
Go around front to the front tire and pull both the left and right ends of the string tight and make sure it looks straight no kinks from back to front. The string should be tight across the rear face of your tire and then straight up toward the front where it passes equal distant from the left and right sides of the front tire face.
This is exactly the same angles as using a straightedge or light bulb tubes or whatever. And it won't shatter.
If you are off and the string is crooked then adjust your rear adjusters to pull your rear tire one way or the other until everything is perfectly squared up.
It may take a few tries but you will get better the more you practice.
Unless your swing arm is bent your chain and sprockets should now also be perfectly centered.
Take it for a ride and check the steering feels wonderfully natural and balanced pulling either left or right. Take some curves and check the steering should feel like it steers itself.
You are done. Perfect steering is what makes for magic on a bike.
Anyway that's how I have been doing it the last fifty years. This was a long post but any rider that likes a great feeling bike should know about alignment and how to tell it is off. Just MHO.
 
#27 ·
If you get basic alignment right all future chain adjustment is by even turns of the adjuster either side. Axle stands or similar and fishing line are all you need. Trumpettwins is dead right. I have set up cars this way complete with toe in and out for IRS and Ackerman steering radius etc., and they needed no adjustment when 'proved' on a laser set up.
 
#28 ·
If you get basic alignment right all future chain adjustment is by even turns of the adjuster either side.
Well and good, until you have to remove the rear wheel, or, as I often do, have to loosen the adjusters and kick in the wheel (loosen it) to compensate for overtightening, then adjust again. You can only adjust from looser to tighter, not the other way around.

I use the Motion-Pro rod tool, clamped to the bottom of the sprocket because I'm too lazy to remove the chain guard each time I adjust.
 
#30 ·
If you're referring to me, I know how to adjust the chain, and it needs to be done more often than "once every couple years". The "overtightening" is a result of the usual trial-and-error adjustment. As I said, you can't go from too tight to looser with the adjusters, you can only go from too loose to tighter, so every now and then when I overshoot (overtighten during the process), I have to loosen the adjusters, kick in the wheel, and adjust again. Not a problem, just a part of the process.

Is that clear enough?
 
#33 ·
I stick by my story: Aim your TIRES.
Where they point is a big deal. Your chain not so much. It will follow your tires.
And of course check the chain tension every couple hundred miles when you lube it.
If your chain is getting stretched out once the tires are straight all you have to do is equal turns out on the axle adjusters which will NOT disturb your tire/chain alignment IF the tires were straight in the first place.
Try going a little bit slower and you will not overshoot the tension.
And if you DO make the chain too tight just kick it back in and check the tires with a string again.
I stick by my story. Get your TIRES straight as being off by even a little will really screw up the bike's "feel."
Once you spend time setting the tires and testing your bike tracks like it is on rails you will be a believer that tire setup can be felt immediately.
 
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