Chain and Sprocket problem....maybe???

[beddowsm]

I am having concerns over my chain and sprockets. It first occured about a 1000 miles ago (under 2 weeks ago on my Scotland trip). I heard a grinding noise when in low gears. I put the bike on it centre stand and dropped it into first gear. The chain seemed to jump about and grind. Turned out the noise issue was the rear wheel bearings which have now been replaced. However, I am still getting the jumping chain when on its centre stand.

I checked the front sprocket today to see if it was worn - teeth look OK, on front and back sprockets.

But I did notice some free play in the front sprocket. Is this normal. Easier to show with a video!



Heres a clip of the bike in first gear on its centre stand. The engine is cold eg just started after standing all night. With weight on the bike and riding in first I expect it wont be as bad...but this is just to highlight my concerns.



And finally, should there be side to side movement in the chain? I have approx 60 mm verticle play in the chain, but the side to side worries me.



I have ridden like this at speed for the past 1000 miles, approx 400 miles since replacing the wheel rear bearings.

Should I be worried or am I just being paranoid. With an offroading day next Saturday, and Galloway the week after I want to get all niggling doubts as to my bikes safety out of the way.

[ukTiffy]

The "play" in the front sprocket is normal and necessary. However that twisting isn't normal. I'd have that front sprocket off and be looking at the state of the output shaft. With luck the play is due to the sprocket being worn and not the shaft damaged.

You shouldn't be getting much side movement of the chain and if you do then the chain is worn and going to need to be replaced soon. This is also the reason for the "jumping" of the chain due to the variable tenson/ stiffness of the links in the chain. However I rode my @ for a few thousand miles with a chain in this state. Low speed/rev control was a bit 'jerky' due to the chain jump/ variable tension and it chewed a hole through my chain slider ... made TLD "interesting" and short for me as I was worried about the chain breaking in Ireland.

How many miles has this chain done? Depending on how much side movment you're getting it looks like it's time to be looking at a chain set for your bike.

[ADE THE BLADE]

The "play" in the front sprocket is normal and necessary. However that twisting isn't normal. I'd have that front sprocket off and be looking at the state of the output shaft. With luck the play is due to the sprocket being worn and not the shaft damaged.

You shouldn't be getting much side movement of the chain and if you do then the chain is worn and going to need to be replaced soon. This is also the reason for the "jumping" of the chain due to the variable tenson/ stiffness of the links in the chain. However I rode my @ for a few thousand miles with a chain in this state. Low speed/rev control was a bit 'jerky' due to the chain jump/ variable tension and it chewed a hole through my chain slider ... made TLD "interesting" and short for me as I was worried about the chain breaking in Ireland.

How many miles has this chain done? Depending on how much side movment you're getting it looks like it's time to be looking at a chain set for your bike.

i was under the impression this was normal as the drive chain is not under load as such ? just for the record,mine does it and i ain`t losing sleep over it !

[StumpyFingers]

I would say the sprocket has worn out and the chain has a couple of tight links.
A new set should cure the problem.

[fw750x]

Beddowsm Your front sprocket WAS done several thousand miles ago ,The excessive side ways movement in the chain and the jumping up and down also says the chain WAS also done several thousand miles ago.Do yourself a big favour and park the bike until these parts along with the rear sprocket ARE replaced .If you keep on riding the bike in that state you Might be lucky when the chain breaks it will just wreck the casing , Or you could be unlucky and it will lock your back wheel solid in the middle of a bend causing you to crash .Bite the bullet and get it fixed.Francis

[foz1969]

A couple of "stiff links", & most probably the "soft link". Just replaced mine, with DID zvm2, new rear & OEM front sprocket, as we keep getting reminded by the xrv demi-gods. Didn't reach 7000miles on my last chain & i ride... like.. errm... someone between 25-55 years old, but i .do inspect/maintain almost daily. The chain before that snapped doing 70 on dual-carriageway, lady on the back!!!. Think of it like this "you're not spending money.. you're saving your life". Plus the ride is noticably better.

[beddowsm]

Thanks for the replies. Will be getting a new chain and sprocket ordered today....

[BobA]

Keep your fingers crossed!

Looking at the first vid, I'd be a bit concerned about the state of the shaft, as that is an awful lot of play. Pray it is only the sprocket that is worn!!


Good Luck



Bob

[jasonbc]

[QUOTE=beddowsm;486263]The chain seemed to jump about and grind. I am still getting the jumping chain when on its centre stand.

But I did notice some free play in the front sprocket. Is this normal. Easier to show with a video!


And finally, should there be side to side movement in the chain? I have approx 60 mm verticle play in the chain, but the side to side worries me.

You got to remember the chain will jump when up on the centre stand as the suspension is unloaded and hence the chain is not tensioned, so if the chain is slightly too slack that will look amplified when the bike is unloaded on the centre stand.
The play in your front sprocket can't really say if it's excessive i've never owned an At or TA but what you have there is very similar amounts of play to every xr i've ever seen or ridden. Did you notice what it was like when you first had the bike just asking incase you've notice it getting worse.
Sideways play there should be next to none when a chain is new it does indicate wear on the rollers have the same problem with the IRIS chain i have on my XR at the mment that needs replacing badly at the moment

[BobA]

When the bike is in gear and running on the centre stand, there will always be "whip" in the chain, causing jerky movements. As soon as there is some resistance, i.e the bike is on it's wheels with a rider on it, this whip will be dampened out, and not seen or felt.

My feeling is there is some wear in either the shaft or (hopefully) the front sprocket, which should be your primary concern. Although fitting a Honda front is a recognised "must do", I actually found that a good pattern sprocket was a more exact fit on my output shaft. I still fitted the Honda one though!!

The chain will continue to work, but is certainly something you need to address. The sideways movement COULD make the chain ride off the rear sprocket, and if it does will almost certainly see it jamming or breaking, whipping round and damaging an engine case, or launching you into fresh air.


Obviously, we're all messengers of doom (!!) and it isn't actually as bad as all that. Just work your way through logically replacing anything with wear, and take an extra special look at the sprocket/shaft.




Bob