Recommended Chain Slack

[burnrich]

I've measured the chain slack on my GPX 250 today and the total is 55mm. Considering I only just bought the bike and the chain and sprokets were caked in grease and dirt I'd hazard a guess and say they have probably another 5,000km left on all of them before it's change out time. My question to the community is should I bother adjusting the slack or just leave it be until the change out? I read on one of the Australian forums not to worry about overslack chains as they won't cause a lot of damage towards the end of the service life. Any truth to that?

[cuong-nutz]

Looser is better than too tight. I would recommend you clean the chain and inspect it for overall stretch and kinking. Also, you might want to check if the o-rings are still there too. If you notice that the chain tightens and loosens when you spin the rear wheel, you have a stretched chain. 1-1.5" of slack is good.

[burnrich]

Originally Posted by cuong-nutz

Looser is better than too tight. I would recommend you clean the chain and inspect it for overall stretch and kinking. Also, you might want to check if the o-rings are still there too. If you notice that the chain tightens and loosens when you spin the rear wheel, you have a stretched chain. 1-1.5" of slack is good.

Thanks mate. I think it's near the end of it's life and so have done just what you have suggested. I didn't think tightening a stretched chain would do it much good anywayz.

[Racer x]

22~25 mm. Loose is best. To tight will destroy your chain and sprocket set . And can damage your engine.
Clean is a very good way for a chain to be. Also use a straight edge or a metal coat hanger to make sure the chain is straight as you adjust it.

[cbinker]

sounds a little loose. as others have said tighten it up to 22-25 mm

[Motofool]

Originally Posted by burnrich

............I read on one of the Australian forums not to worry about overslack chains as they won't cause a lot of damage towards the end of the service life. Any truth to that?

No truth to that.

If the chain breaks, a lot of damage will happen.

The recommended slack for your bike, while on the central stand and rear tire in the air, is 35~40 mm.

Actual condition is measurable and links ready to fail (if any) can be seen only after cleaning the chain.

Please read these:
http://www.ninjette.org/forums/showthread.php?t=133019

http://www.ninjette.org/forums/showp...89&postcount=5

[csmith12]

Originally Posted by burnrich

I read on one of the Australian forums not to worry about overslack chains as they won't cause a lot of damage towards the end of the service life. Any truth to that?

[burnrich]

Exposed drive chains have never made any sense to me. Does anybody think we will ever see a return to the old days of enclosed chains that require jack all maintenace? I suppose shaft drive is the only other alternative for road bikes.

[7oxSin]

Originally Posted by csmith12

[burnrich]

Originally Posted by 7oxSin

Being factious doesn't actually answer the question.

[7oxSin]

Originally Posted by burnrich

Being factious doesn't actually answer the question.

what? i wasnt responding to you? btw you forgot belt drives.

[Racer x]

Originally Posted by burnrich

Exposed drive chains have never made any sense to me. Does anybody think we will ever see a return to the old days of enclosed chains that require jack all maintenace? I suppose shaft drive is the only other alternative for road bikes.

In the early days of bicycle development the chain was housed in a box. Heavy metal chain guards that kept the chain dry. The English used this the most. The French designs rarely had chain guards.

The problem with them is they trap dirt and water.

The chain is an amazing thing .Transferring power and waisting very little. But it does require maintenance.

[csmith12]

Originally Posted by burnrich

Being factious doesn't actually answer the question.

Sorry, we have a lot of fun here but nothing really can be added about the chain slack that Motofool and Racer X already posted.

Gratz on your purchase! I hope she serves you well.

[Motofool]

Originally Posted by csmith12

..........nothing really can be added about the chain slack that Motofool and Racer X already posted.........

Yes, I can !!!

We have lots of good sport fun here ............... and also perform some interesting experiments, reviews, etc.

This one, for example:
http://www.ninjette.org/forums/showp...17&postcount=1

Yes, one bike was rolling with this sprocket:

[burnrich]

Originally Posted by csmith12

Sorry, we have a lot of fun here but nothing really can be added about the chain slack that Motofool and Racer X already posted.

Gratz on your purchase! I hope she serves you well.

Ever had an over tightened chain snap and drop off the bike in the middle of nowhere? Some hack mechanic tightened my chain for me (which was fine prior to said tightening) on my first bike a long time ago and the chain link just snapped in half and left the chain on the road somewhere before I'd even realised that it wasn't gearbox trouble (per say). If it weren't for the person that stopped and drove me back into town (another fellow biker) it would have been a very long walk home in the dark.

And that's the reason why having the chain a little loose I think is better than it being tightened to within an inch of it's life.

I'm not confident tightening the chain to within workshop manual spec and then performing a wheel alignment without a laser wheel aligner which needs to be done if you don't want to screw up the geometry of your bike.

[burnrich]

Originally Posted by csmith12

Sorry, we have a lot of fun here but nothing really can be added about the chain slack that Motofool and Racer X already posted.

Gratz on your purchase! I hope she serves you well.

I agree with the guys by the way Was just trying to make a point about doing your own adjustments when you don't know what your doing. Some mechanics are just scary.

[csmith12]

Originally Posted by burnrich

Ever had an over tightened chain snap and drop off the bike in the middle of nowhere?

On a dirt bike in the middle of 100 acres of woods count? Pushing it out blows.

We eye-ball it at the track. Trust your gut, if it looks too sloppy... it probably is.

[burnrich]

Originally Posted by csmith12

On a dirt bike in the middle of 100 acres of woods count? Pushing it out blows.

We eye-ball it at the track. Trust your gut, if it looks too sloppy... it probably is.

ha ha depends how far into the 100 acres you were and if there were any bears around.

[Motofool]

Originally Posted by burnrich

Ever had an over tightened chain snap and drop off the bike in the middle of nowhere?..........
And that's the reason why having the chain a little loose I think is better than it being tightened to within an inch of it's life..............

They can also jump out of track if too loose.
The recommended slack is not a precise thing.
Like most things with motorcycles, it is just a compromise between two evils.

The condition of the chain has little to do with that compromise or recommended range of slack.
I would say that a weakened worn chain would be less tolerant to being working out of that range.

A healthy chain is over-qualified to transmit the force involved in the torque output of your engine.
Making it work out of that range introduces two huge forces that may take the chain and sprockets and bearings to and beyond their limits.

One is the force exerted by the swingarm when it aligns both sprockets and its pivot (not much slack here).

The second force is generated by the excessive bouncing up and down of both branches and the centrifugal tendency while going around the sprockets.

Even more, a new chain deviates little from a horizontal line when supported sideways by the extremes.
A worn chain, however, takes a curvilinear shape.
That indicates that it is easier for a worn chain to get derailed, especially if the sprockets are out of alignment.