Stretched chain

[steved]

Hi all

Upon trying to tension my chain today, we discovered that the chain was stretched unevenly. Is this something I should get seen to very quickly, or is it something that I should fix, but is not critical?

Your advice is much appreciated.

[Jantar]

Depending on how bad the uneveness is you can either put up with it, or replace both your chain and sprockets.

Try tensioning it at its tightest spot as that is where the chain is still in its best condition. Rotate the rear wheel until the chain is at its loosest point. If the amount of slack is within tolerance (25 - 35 mm) then accept it for a while, but be warned that uneven chain wear will accelerate the wear on your sprockets.

If it is outside tolerance, then replace as soon as possible.

[Jackrat]

I take it you mean it has tight spots??
If so,yes it's on it's way out and really should be replaced.
It's not a real biggie,just needs replacing in the near future.
Will pay to do the sprockets at the same time.
I find I do my rear sprocket twice for every one front but some people do both at the same time.
Just depends on your situation.
Cheers.

[Ixion]

How much unevenly ?

Some degree of uneven wear is IMHO inevitable.

But if tensioning for 1 inch play at the tightest point means 6 inches at the sloppiest, then it obviously need replaing ASAP.

I guess anything up to an extra inch (so 1 inch at tightest 2 inches at loosest) I wouldn't do anything in a hurry UNLESS it was a bike that I rode hard and fast. Or my sprockets were in very good nick, becasue a worn chain will take the sprockets with it.

Usually however the sprockets will be dodgy also , so once it goes past that extra inch I'd budget for new chain and sprockets in the near future.

You can also check the wear by winding the chain around until the loosest part is wrapped around the rear sprocket. Try to pull the chain away from the sprocket. Any daylight between chain and sprocket means the piggy bank's in danger.

But unless it's extreme with the chain about to jump off the sprocket, it can usually wait a pay day or two if necessary.

[steved]

I take it the chain pulls unevenly on the sprockets, wearing out the teeth unevenly? Yes to tight spots Jackrat. The slackness of the chain depends on chain position.

Thanks all. Ya'll saved me some stress. I'll replace it within a couple of months but I'll calm down from trying to replace immediately.

[Motu]

Chains don't get tight spots,they wear evenly throughout - tight spots are caused by sprocket eccentricity...mark the tight spot and see how often it lands in the same place.

[Jantar]

Chains don't get tight spots,they wear evenly throughout - tight spots are caused by sprocket eccentricity...mark the tight spot and see how often it lands in the same place.

Umm, Have to disagree with you here Motu. Chains DO get tight spots. Well, actually they get loose spots due to all manner of abuse that they suffer. Uneven chain wear then causes sprocket eccentricity, which helps to accellerate chain wear etc. This is one of the reasons that chain and sprockets are usually replaced at the same time.

On my RE5 I only expect 6000 km from a chain when I use it on gravel roads, and around 10000 km on sealed roads. The main cause is uneven chain wear. When I first experienced this phenomenal rate of wear on one of the first RE5s in NZ (in 1975), Suzuki took one of my worn chains for analysis. There WAS uneven chain wear, and the next model RE5s (A model) were fitted with O ring chains.

[Will]

Just replaced my chain and rear sprocket.

Had an O ring chain and now run a heavier X ring.

Leading up to the change, I was riding very carefully, with no snatching because I could feel the tight spot going around. Funny how the old one suddenly seems to deteriorate. I did not do many k's until it was replaced.

The new one is fantstic and so positive after the old.

[Bonez]

Just replaced my chain and rear sprocket.

Had an O ring chain and now run a heavier X ring.

Leading up to the change, I was riding very carefully, with no snatching because I could feel the tight spot going around. Funny how the old one suddenly seems to deteriorate. I did not do many k's until it was replaced.

The new one is fantstic and so positive after the old.

Just got around to checking the GBs front sprocket this mourning. Its faaaarkkkkeddd. So will replaced it an the rear sprocket when I get the O'ring chain next week. This is also a good starting point for monitoring/servicing purposes.

[TonyB]

You might be over tightening the chain. I used to do it too.

As the swing arm moves up and down through its travel, the distance from the front sprocket to the rear sprocket chages slightly. This is because the swing arm doesn't pivot where the front spocket is.

The important thing to remember is that the chain will be at it's tightest when the drive sprocket, swing arm pivot and rear sprocket centres are all in line. This is when the rear sprocket is furtherest from the front sprocket. If you don't have the correct chain slack, when the rear suspension compresses to this point it will strestch- or damage the output shaft bearings...

If you want to be really pedantic about getting it right, use some small ratchet tie downs to compress the rear suspension by wrapping them around the swingarm and rear subframe. Wind them up till everything is inline as described, then adjust the chain so it has very little slack.

You might also find the rear suspension feels a lot better too....

[bugjuice]

I used to over-tighten the chain, not on purpose, but when I had it 'right' then put it all back together and tightend the axle up, it was then too tight...?!?! So not, I make a habit of getting it to the 'right place' then doing a half turn loose again so the chain slacks off a bit more. Then when I tighten everything back up, the chain is about right.. sweeeeeet

I used to have a CBR250RR with a rooted chain. I got the chain and both sprockets changed at the same time for about $120 all up and it felt like riding a new bike afterwards..

Make sure to keep the new one well lubed too, so that it'll last that bit longer

[Pixie]

If you see 'kinks' in an o'ring chain (where some chain links won't pull straight because the pins are seized)It is because the lube has leaked out and water has got in,often you will see rust powder on the links.I have several of these hanging in my shed.

[moko]

I`m in the same situation,my chain hardly needed touching for 15,000 miles (think that`s about 32000k`s or something)but when it went it went and the bloody thing`s full of tight spots.got one on order that should be here next week but in the meantime I`m taking things very easy,not happy riding like it at all but it`s my only transport and I expected my chain & sprox to have arrived by now.Current adjustment is very much a compromise.Having an over-tight chain can trash wheel/gearbox bearings as well.When I started riding advice was always to get a mate to sit on your bike while you checked the tension.

[Ixion]

I think it's once the case hardening on the roller inner surface wears through. Then they just start to wear real fast. And since some rollers go earlier than others , that's why you get tight spots. Crack a few links on a worn chain and you can see the wear on the roller inner surfaces.

They take the sprockets out because once the chain wears, under laod it no longer matches the pitch of the sprocket teeth. So the load is taken on the wrong section of the tooth form.

[steved]

I used to have a CBR250RR with a rooted chain. I got the chain and both sprockets changed at the same time for about $120 all up and it felt like riding a new bike afterwards..

Make sure to keep the new one well lubed too, so that it'll last that bit longer

Crikey that's cheap. Where was that?