How big a deal is riding a few thousand km with a too-tight chain?

[nerrrd]

Turns out I'm useless enough to have ridden my new bike for quite a while with the chain too tight - my old bike was lucky enough to be belt-driven so never had to suffer too much from my mechanical ineptitude (except for that time I set it on fire a bit while disconnecting the battery, but that's another story).

Dealer mentioned that a too-tight chain will cause premature wear on the rear wheel bearings and possibly the gearbox as well, so I'm just wondering what implications this has for the bike into the future.

Is there any way of knowing for sure what the damage is? Or will it just become apparent gradually as the kilometres rack up (currently on 7,500kms travelled)? Maybe it's one of those 'how long is a piece of string' questions?

Was considering selling this one to side-grade to another bike I almost bought, but wouldn't feel comfortable passing it on to someone else now without giving them a heads up (and if this means a significant drop in value it's probably not feasible anyway).

The bike doesn't feel any different to me than it always has. Only thing I've noticed since loosening it off a bit is a fairly significant increase in fuel economy (according to the dash readout).

Thanks.

[Akzle]

i wouldn't worry about it, but i'm a rough c*nt.

why was it too tight? if it was too tight before you were sitting on it, it will have been wayyyyyyy too tight once slung.

[gjm]

Depends on many things. What's your riding style? If you ride hard, you'll do more damage anyway, but a too-tight chain will exacerbate this.

The sprockets and chain will wear faster, and the improvement in economy will be (in part) due to a decrease in friction once the chain was loosened off a bit.
If you ride gently, you're much less likely to have done any internal damage.

Check the sprockets and chain for wear, replace if there's any question about them, and make sure the new chain is adjusted properly.

[GrayWolf]

Turns out I'm useless enough to have ridden my new bike for quite a while with the chain too tight - my old bike was lucky enough to be belt-driven so never had to suffer too much from my mechanical ineptitude (except for that time I set it on fire a bit while disconnecting the battery, but that's another story).

Dealer mentioned that a too-tight chain will cause premature wear on the rear wheel bearings and possibly the gearbox as well, so I'm just wondering what implications this has for the bike into the future.

Thanks.

If it's tight enough to increase fuel consumption noticeably? Apart from the excess wear etc o both chain and sprockets,,,,, the worst strain is whe the suspension is working... (loosens and tightens, hence a 'minimum slack') it will also end up wearing the gearbox output shaft seal and it will start weeping. That could take a bit of time, several over-tightening's, unless it's an old high mileage machine???

[nerrrd]

I think this is what happened:

Was a brand new bike in January. Not long after I got it I felt something 'give' a little when I was riding it so took it in for the dealer to check. They decided the chain had stretched, was too loose and adjusted it for me.

Not long after that I got a centrestand on the bike. Since then the few times I've adjusted it has been on the centrestand, without any weight on the suspension (somebody will have told me not to do that at some stage, in fact it even says not to in the manual, and it's gone in one ear and out the other). I think because it was too loose early on I've tended to err on the side of tighter rather than looser, and guess-timated without properly measuring it. So with the bike's weight and my weight on top of that...

On the plus side I'm an anti-hoon, the bike redlines at a whopping 8500rpm :sarcasm: and I rarely go over 4000. In fact that's part of the reason I was thinking about side-grading, the other bike probably suits my style better (redlining at 6500.) So it hasn't been ridden 'hard', if anything too soft, which they tell me may not be doing the engine any good either.

[avgas]

Also check your weight. Depending on the suspension - if you "sag" the bike a bit, it is actually a bit better to have chain a bit loose rather than a bit tight.
Seen a few FF wreck chains because they dialed it up, then sat on it and suspension became negligible as the bike basically held itself together by chain tension.

[Flip]

Don't think you will have a problem. Chains have a bit of stretch in them so I don't believe you would have damaged anything.

[Ocean1]

Don't think you will have a problem. Chains have a bit of stretch in them so I don't believe you would have damaged anything.

I don't think he has a problem either, but not because his chain stretched.

In fact chains stretch fuck all under any load much less than that required to completely fuck them in fairly short order.

Which is well enough to damage countershaft bearings pretty quickly, then shaft seals, sprockets and then a bunch of other stuff, depending on the machine.

If none of that's happened then it's unlikely his chain was tight enough to do much damage at all.

But the Nerdy gentleman would be well advised to read his manual, which will instruct him in one of several different ways to get it right.

[Flip]

Using the published drive design data from Reynolds and making a few assumptions for motorcycle drive chain.

A std 530 size drive chain will extend 41mm before it reaches it UTS. Given bike chains are usually driven at about a SF of 8, I would expect a drive chain to be stretching about 2.5mm under normal operation.

As this is based on commercial industurial chain a stronger heavy duty would stretch a bit less.

[Ocean1]

A std 530 size drive chain will extend 41mm before it reaches it UTS. Given bike chains are usually driven at about a SF of 8, I would expect a drive chain to be stretching about 2.5mm under normal operation.

Aye, but it's elastic limit is maybe half of the uts, if that.

The point was that if the chain on most bikes is set up tight-ish as it sits on it's stand then the sprockets will be around 15-20mm further apart loaded, when the swingarm is in line with the countershaft, which means 30-40mm of extra chain length, and the leverage it's got in getting there is prodigious. That's enough to put you well past the elastic limit of the chain and riding it like that will definitely cause serious damage to the chain and probably mechanical damage elsewhere.

If that damage wasn't evident when the shop saw the bike then the chain tension probably wasn't too bad.

[biketimus_prime]

So wait, are you meant to adjust your chain with both wheels on the ground? I have always done it while the bike was up on my paddock stand. The manual even says put the bike on the center stand first? I measured about 25-30mm slack when everything is done up tight and wheel is off the ground... Is the slack measured with the wheel on the ground?

[Ocean1]

So wait, are you meant to adjust your chain with both wheels on the ground? I have always done it while the bike was up on my paddock stand. The manual even says put the bike on the center stand first? I measured about 25-30mm slack when everything is done up tight and wheel is off the ground... Is the slack measured with the wheel on the ground?

All bikes are slightly different, so the correct answer is do it how the manual says.

However, you can't go too far wrong by doing it so: http://www.kiwibiker.co.nz/forums/sh...post1130429055

[nerrrd]

Feeling reassured at this point, thanks to all who posted advice.

[AllanB]

Seriously it is a hell of a problem if that chain is wrapped around your balls for 1,000 kms - heck that 12 odd hours at leasrt of travel with that ball chain slowly cutting off the circulation of your man-sacks.

[nerrrd]

Now this thread has that special 'KiwiBiker' flavour. You have my sympathies if you're speaking from personal experience.

Or...the phrase is 'ball & chain', not 'ball chain'. Although they have a similar effect to the one you describe for some, so they tell me.