Chain getting tighter over time?

Hello guys. I have a problem with my chain, it seems that it has a mind of it's own, it should get slacker not tighter over time!

Thing is that i've cleaned, lubed, and adjusted the chain slack at the tightest point as per manual.

After 150-200 miles i have found the chain being tight as a guitar string, the chain making a grinding noise at low speed(this is how i've figured out that there's something wrong). What can be the cause? All the nuts seem to be alright.

I have a torque wrench and the axle nut is tightened at the required spec, and the locknuts from the adjusters are tightened properly.

I know the long term damage of a over-tightened chain on the output shaft bearings and the gearbox so i would like to avoid that!

The sprockets could be misaligned or the chain is knackered. How many miles has the chain done?

If you did set the slack at the tightest point.....then is the wheel/axle moving back in the swing arm? Check by resetting chain tension......rotate wheel a few times randomly to see if you've still got sufficient slack, then tighten axle nut - then check again! If all still OK, put marks on axle, nut, carrier and swing arm. A dot of tippex (see, there are still uses for it!) will do the job, or China graph pencil, run bike and check to see if anything has moved. You are dead right about the risks of running a chain too tight - just don't.

Just thought, are you setting chain tension exactly as described in the manual (ie. on/off stand, someone sitting on it etc.)?

That can make a big difference.

Thanks for reminding me why I only like shaft-driven bikes!

[mention]megawatt[/mention]

About 7000 miles? I think it needs changing! . The adjusters are only half way through just now, i had to tighten the chain 3 times in 4000 miles.

[mention]Speedy23[/mention]

Yes, exactly as per manual!

In November i will send the bike for the MOT and i'll change the chain and sprockets then.

Try pulling the chain straight back off the rear sprocket at the 3 O clock position. All signs are that it's knackered. Buy a new chain AND SPROCKETS. DID X, Ring gold is the best and will last the longest.

Chain getting tighter!

Can only be a couple of things that can cause that:-

Seized link - Check by running the chain by hand (seized link(s) should be easy to spot).

Suspension failure - Has the bike height changed (lower)?

Incorrect adjustment - Check with weight on the bike - should still have a small amount of slack in the chain.

Fractured frame / frame weld - Allowing the frame to 'stretch' (highly unlikely).

Note: loose adjusters or loose axle nut will allow the wheel to move forwards, making the chain too slack and, when braking, make the chain too tight.

You are re checking it AFTER tightening the axle nut I presume . The pinching together of the swing arm is often enough to move the wheel back a fraction and this will tighten the chain further.