Chain tensioning
 

I think this as been posted before, but cant find it if it has,

My chain is looking a bit loose, and am looking a nipping it up at the weekend,
The manual advises about 20-30mm, what i want to know is ,

Is that with no weight on the bike or with weight on the bike ?,
If its with weight on it fair enough, but what tolerance would you recommend with no weight on the bike as you measure the slack??

Thanks for any help

My mechanic did mine with a bit of weight on the bike. He did not actually measure the chain travel but kind of used the "fingerometer" method while leaning his weight over and rocking up and down on the seat as he felt the chain travel. I kind of figured he had done hundreds of these and knew what he was doing...it stopped the chain slap anyway.

The really important thing is to see if the chain has any tight spots and if so, make sure the adjustment is made in the tightest part of the chain so as not to overload the gearbox bearings.

The fingerometer method is fine as it doesn't have to be that exact and as regards weight, there's not a huge amount of difference if you lean on the bike or not provided it's on the side-stand so the weight of the bike itself is on the back wheel/rear shock.


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Do it with the weight you normally have on your bike whilst it is in use. Do the main check after you have tightend the axle, nipping up the nut pulls the ends of the swinging arm together hence moving the wheel further back in some cases it will take out the slack. Again check for tight spots it is not unknown for sprockets to appear eliptical due to mounting or kinks & tight links to affect the chain. If there are serious differences at points in the chain or sprocket positions & you cant fix them replace the chain & or sprockets. You will only hammer gearbox, swingarm & sprocket bearings admitedly this will be in extreme cases & you will feel it.

Thanks for the replies,

I know im not a mechanical wizard, but am getting braver, but 'tightspots' what are they ?

Are they links that are a little stiffer than others or what?

I've heard of the fingerometer method, and that should be ok as a guide

Thanks again for help

Yes, it's where a link doesn't move around it's pins sufficiently and therefore is stiff and temporarily shortens a section of chain as it goes around the sprocket causing undue wear on the sprocket bearings.

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A tight spot doesn't necessarily mean stiff links. When a section on chain is worn more than another, the less-worn section is the tight spot. A section where the pins and/or the holes in the plates are worn more than in another means the chain has effectively stretched - the pin to pin distance has increased. This is when the sprocket wear really accelerates. Another wear test is to see how far you can lift the chain off the back edge of the rear sprocket. You shouldn't be able to lift it much at all on a new chain - perhaps a millimeter or two. Extremes of this sort of stretching are dangerous, as under load, the chain will climb up the teeth and possibly jump off the top if it's very worn.

Cheers , will look out for them at weekend, i take it a good clean and relube will sort out the tightspots

My tight spots were caused by the rear sprocket being installed the wrong way around causing sprocket mis alignment.
As a matter of fact every sv i've takin notice of has the rear sprocket on backwards.
It's very easy to look and see if yours are mis aligned.