Rear wheel alignment

[Maestro]

Aight, this has been bothering me for a while. I tightened my chain a few weeks ago. I think I may have turned one of the adjustes slightly more than the other though. The reason this happened was because the plate at the butt end of the right swing arm was loose. I tried tightening the adjuster against it to stop it from rattling but it didn't fix the problem. Of course, every time I tightened the right adjuster, I tried to tighten the left one by the same amount, but I don't think it was perfect. Anyway, I used the "string" method to check the rear tire alignment and as far as I could tell it looked ok. I was wondering if there was a way to "true" the adjusters though to make sure they were exactly the same and then re-tighten the chain. Also, the fact that the right adjuster isn't butting up tight against that back plate worries me. Could that cause problems down the road with vibrations causing the adjuster to move while i'm riding? (sorry, i know this post is long. if anything i'm talking about is unclear i'll try to elaborate, possibly with pictures)

[rictus01]

OK if one back plate is loose then it isn't doing anything, the marking lines are at best a rough guideline as they are mass produced.

Your best bet is to re-set from scratch, undo the axe, then push the rear wheel as far forward as possible, make sure the axe moves easily, take out the chain slack keeping the axe at 90 degrees to the swingarm legs, do up the nut on both adjusters to support this position.

get a straight edge and run it across the ridgeline on both front & back of the tyre (where tread meets sidewall), and extend it to th front wheel, measure the distance front the tyre at the front axe point, repeat on the otherside.

this will give you a point to adjust to to make both measurements even.

at this point you can use a punch to mark the adjuster plates in the swing arm as level (you'll see how far out they are as standard).

Adjust the chain by 1/4 turns to each adjuster until it's correct.

Torque up the rear axe bolt, job done.

I would never rely on the adjuster plate marking for more than a guide as the wear of the bushes and and slight distortion of the swingarm won't be taken into account, I have a new fangled lazer thing for wheel alignment but to be honest is no better than a straight edge and ruler.

Cheers Mark.

[ejohnh]

Aight, this has been bothering me for a while. I tightened my chain a few weeks ago. I think I may have turned one of the adjustes slightly more than the other though. The reason this happened was because the plate at the butt end of the right swing arm was loose. I tried tightening the adjuster against it to stop it from rattling but it didn't fix the problem. Of course, every time I tightened the right adjuster, I tried to tighten the left one by the same amount, but I don't think it was perfect. Anyway, I used the "string" method to check the rear tire alignment and as far as I could tell it looked ok. I was wondering if there was a way to "true" the adjusters though to make sure they were exactly the same and then re-tighten the chain. Also, the fact that the right adjuster isn't butting up tight against that back plate worries me. Could that cause problems down the road with vibrations causing the adjuster to move while i'm riding? (sorry, i know this post is long. if anything i'm talking about is unclear i'll try to elaborate, possibly with pictures)

I dont like the string method myself, I think it's too prone to error.

Get two x 2 metre(approx) lengths of right angle section aluminium, and 2 x 20 cm sq (approx) lengths of wood of

slacken rear axle and put bike on rear stand.

Push wheel forward until chain is too slack. tight rear axle nut until it just nips but will move when the adjuster bolts are turned.

Screw adjuster bolts until neither of the backplates are loose.

place lengths of wood at front and back of bike to support the lengths of ally section and arrange ally until it abuts the front and rear of back wheel on both sides.

Turn front wheel until it is parallel with ally section and measure distance from the section to the wheel on both sides. Turn relevant chain tension adjusting bolt until distance from ally section to front wheel is same on both sides. You will need to constantly ensure that the all sections are butting up against the rear wheel cos each time you turn the adjusting bolt the rear wheel will twist slightly. If the chain becomes too tight while aligning the wheels you will have to slacken of the adjusters and push the wheel forwards again.

When you achieved alignment, mark the position of the adjustment bolts against the end plates.

Proceed to tighten the chain to the correct tension by turning the adjustment screws equal amounts at a time. Make sure you are measuring the slack at the tighest point. Slackening the chain is a pain in the a*s so try to get it right when tightening ;)

When all correct tighten the rear axle nut to correct torque. Your wheels should now be aligned with each other , you chain tension correct and your adjustment nuts tight.

Bit of a long winded description but it's easy to do if you get the right stuff.

When I get time I'll set up my kit in the garage and post some pics of it. Too cold now.. :(

[ejohnh]

ah - rictus beat me to it.. :D

[Maestro]

Thanks guys! I think I'll give this a try and let you know how it goes.

[zadar]

I measure from swingarm pivot center to axle center on both sides.I set this same.once there going back or forward with axle I count turns on adjuster bolt.tread pitch is same so both sides will travel same distance for each revolution or part of it.
to keep plate tight easier way is to jam rag or screwdriver handle between chain and sprocket,rotate wheel to put tension on chain.it will pull wheel forward against adjuster bolts.while there tighten axle.

[yorkie_chris]

Yup I use this method too

[Maestro]

Ok, sorry it's taken me so long to reply. I tried the method using the 2 meter aluminum straight edges but it didn't make sense to me after about half-way in. From how I understood it, the rear wheel would be aligned with the front wheel, but this still means that the rear sprocket could be out of alignment with the drive sprocket (which, isn't that more important?). I sat there and tried to think of a method to make sure the two sprockets are aligned properly but couldn't figure anything out. Would it work just to unscrew both adjuster nuts completely, and then screw them back on together equally (turn for turn, also making sure that the swing arm guides are relatively equal) until the chain reaches the proper tension?

[yorkie_chris]

No because you don't know that the screws are the same length either, or where the threads start in the adjusters.

If the straightedge method shows it to be right, then its near enough.

[ejohnh]

Ok, sorry it's taken me so long to reply. I tried the method using the 2 meter aluminum straight edges but it didn't make sense to me after about half-way in. From how I understood it, the rear wheel would be aligned with the front wheel, but this still means that the rear sprocket could be out of alignment with the drive sprocket (which, isn't that more important?). I sat there and tried to think of a method to make sure the two sprockets are aligned properly but couldn't figure anything out. Would it work just to unscrew both adjuster nuts completely, and then screw them back on together equally (turn for turn, also making sure that the swing arm guides are relatively equal) until the chain reaches the proper tension?

No the important thing is to get the wheels aligned.

[Maestro]

The screws wouldn't be the same size? That seems kinda dumb that they would do that :scratch:

[yorkie_chris]

Tolerences in where the thread start, if the angle iron method isn't accurate enough for you then that could be significant.

The angle iron method works, and as others have said, its the wheel alignment thats important.

If you're going to be that an@l about it then take it to a garage with the laser alignment tools.

[zadar]

The screws wouldn't be the same size? That seems kinda dumb that they would do that :scratch:
you can always start from fully screwed in instead.

[Maestro]

Starting with them screwed all the way in, then backing them out equally works just as well? I might just try that then. Also, why is it more important that the wheels are aligned? If your front wheel isn't straight and in line with the bike then your rear tire will be out of line with the bike as well, right?

[zadar]

If your front wheel isn't straight and in line with the bike then your rear tire will be out of line with the bike as well, right?
right,if forks are bent or frame head or swingarm...if all straight it will be fine.
I like axle to pivot points better.

[ejohnh]

right,if forks are bent or frame head or swingarm...if all straight it will be fine.
I like axle to pivot points better.

If you cannot get your wheels to line up then you have a major bend in your bike - is that likely?

All that axle to pivot alignment tells you that the rear wheel is aligned with the swing arm. Given the build quality of the SV it does not follow that the wheels will automatically be aligned by that method. However, using the straight edge method properly, you are guaranteed to get your wheels aligned , and - at the risk of sounding pedantic - that is what is important. :nomore: from me on this... [-o<

[zadar]

If you cannot get your wheels to line up then you have a major bend in your bike - is that likely?

very small twist at steering head will multiply by the time you get down to wheel.I deal with race bikes which are crashed on regular bases.we measure bikes with computer.you be surprised how many are bent,forks in one direction and swingarm in other.
I rather have one wheel little off than both.rear I mark after measuring so I know how far it is off.front there is no much you can do other than straighten forks/frame.

[ejohnh]

very small twist at steering head will multiply by the time you get down to wheel.I deal with race bikes which are crashed on regular bases.we measure bikes with computer.you be surprised how many are bent,forks in one direction and swingarm in other.
I rather have one wheel little off than both.rear I mark after measuring so I know how far it is off.front there is no much you can do other than straighten forks/frame.

I cannot be doing with this Help!!!

[steveg]

Where I get my tyres fitted they will do a wheel alignment check for free , if needs to be adjusted they use a laser sighting tool costs a fiver .

Cheers Steve