chain adjustment help

[Stu]

Originally Posted by aciduzzo

(kicking and tyre wacking included)

Alternative to that is put a scredriver between chain & sprocket, then wheel the back wheel round to trap the screwdriver. This will pull the rear wheel forward.

Pretty easy to **** it up the first time you do it. I wish I had one of those laser things for my first attempt.

Anything with a straight edge will help you get it "good enough", though.

I've never used the markers, probably should just replace them with simple round washers. The only thing they're good for is gouging unsightly marks into your swingarm.

[TamSV]

Originally Posted by Stu

Alternative to that is put a scredriver between chain & sprocket, then wheel the back wheel round to trap the screwdriver. This will pull the rear wheel forward.

I was just about to post that I put a rag on the chain and feed it into the sprocket to tighten everything up - exactly same principle and works a treat. It's then easier to adjust the chain from "too slack".

For alignment I tend to adjust the wheel to where it looks about straight. Then stand back a bit to eyeball the wheel/swingarm and chain/sprockets and adjust further if necessary, always tightening (not slackening) one adjuster or the other to get the desired adjustment. I then check with a straight edge -but it's usually only a very fine adjustment needed if any.

You then have a straight wheel and can adjust the chain slack by tightening each adjuster slowly and by the same amount each side.

Considering the speed the chain goes round the sprockets (especially the front sprocket). If the wheel is out of alignment even by a small amount, that means the chain is going to rub against the sprockets and vice versa. The point of being so pedantic about ensuring the rear wheel is aligned properly is to save the wear on these components and thus the life span of them.

Apart from that, it can affect the way the bike corners and wear out the tyres quicker. Surely it's worth making sure the wheels are aligned correctly rather than by eye?

I'll take back what I just wrote seeing as I didn't see the bit about using a straight edge.

[TamSV]

The reason for accuracy is still a point worth making Stig, which is why I think it's worth learning to do it yourself.

Plenty of tyre garages just go by the markers (including the one I used to work at)

[Nobbylad]

I reckon I could use my laser spirit level as a straight edge across the side of the rear wheel, pointing towards the front wheel. Then use something as a 'target' for the laser off the front wheel and just measure the difference on each side.

Originally Posted by Stu

Alternative to that is put a scredriver between chain & sprocket, then wheel the back wheel round to trap the screwdriver. This will pull the rear wheel forward.

thanks for that tip, i'll give it go! My main difficulty is getting the slack back (as the chain has been overtightened). I find that the LHS is much easier to slacken than the RHS (as the screw just becomes too loose and does nothing), so maybe the screwdriver trick will help there.

Originally Posted by Stig

You can get a laser alignment tool as well. A small device you hold up against the rear sprocket and point the laser along the length of the chain all the way through to the front sprocket. If the laser hits the same part of the chain through the complete length the rear wheel is aligned. If not then adjust as necessary.

thanks Stig, that makes me wonder whether my laser pen would work. i'll give it a go, otherwise i'll get this gadget!

Originally Posted by aciduzzo

thanks Stig, that makes me wonder whether my laser pen would work. i'll give it a go, otherwise i'll get this gadget!

Not sure it would. The laser has to be flat against the rear sprocket for it to measure accurately. Not sure you'd be able to do that with a pen. It's mm precise. So a very small difference will see the rear wheel not aligned correctly.