Whats my noise?

[roadpilot3]

Hi Guys – time to pick your brains again – sorry it’s a long post.

On Friday whilst riding to work I noticed a slight knocking as I’m riding along.  This is a new knock and I have never noticed it before – she makes other bangs and rattles but this is different.  A quick check in the car park at work reveals nothing obvious falling off and I forget about it for the day.

In the afternoon I ride home to find it has got more noticeable – maybe as I’m looking for it now but I’m convinced it’s really obvious.  All the way home I’m worried about the front sprocket flying off  – having had a sprocket issue on this very bike before.

The knock can be felt through your left boot as it rests on the peg, it seems to be regular like a drum beat.  It goes (or is masked) when I accelerate but is present when I am either maintaining speed or slowing down.  It doesn’t happen in neutral or with the clutch depressed while moving and doesn’t happen when stationary.  I have had the bike on its centre stand and seems to do it in all gears so happens also when it not under load.

There is no change in the bikes performance, no smoke and it still sounds the same.

Things I have ruled out – but I’m happy to rule them back in if you think they might be to blame!

+ My imagination – my mechanic uncle has ridden the bike and can feel the same knock.
+ Oil – It has oil in it!
+ Front sprocket about to fly off– we stuck a camera up there and the nut and washer is still tight and exactly where we left it.
+Wheel bearings – both front, back and sprocket carrier bearings were changed about 2500 miles ago when I fitted new tyres.

Having spent the best part of an entire weekend about this time last year trying to find a metallic rattle which sounded terminal only to find it was one of the LED’s in my indicator that had worked loose I thought I would ask the question on here fist….. “What is my noise?”

I have already ordered a new chain, front and rear sprocket for her – the current ones look OK but are a little worn – but not enough to cause this I wouldn’t have thought.

If it helps the bike is a FZS600s in gold, on a 2000 plate and has covered only 56000 miles.

Thanks guys – looking forward to some suggestions….. 

[His Dudeness]

Sounds like a stiff link in the chain.

[darrsi]

Yeah, +1 on the chain.
 
Put the bike on the centre stand, and looking at the lower level of the chain look for links that are at a slight angle rather than flat horizontal, then see if they move freely or not, you'll be able to tell good one's from sticking links.

[red98]

yep +2 for chain.....is it hitting the underside of the swingingarm  ....ie too much slack/tight spot...

[roadpilot3]

Reassuring to see we have 3 votes for chain – I have a nice DID gold HD on order already as I was hoping this would be the cure – if not it will match the paintwork and will look cool in my garage while I try to work out how to fix it.

The current chain came with it when I brought her about 18 months ago, the chap said it was recently replaced but I never found a receipt in the bundle of service history that came with her so have had to take his word for it and I guess if it as a cheep chain 18 months might be its limit anyway!.

The chain doesn’t seem to be too slack and I don’t think its banging on the swing arm – but it might particularly when its really going for it.  There is a bit of wear which you can detect by wobbling it on the rear sprocket and it seems to have a tight spot as the slack seems to change about half way round but we are only talking a small amount here – but it might be enough I guess – I didn’t see any sticky links though, maybe its just stretched funny? or maybe I’m not looking right!!

Will keep riding her this week (carefully) and with a bit of luck swap the bits over next weekend if they arrive in time – will let you know if it cures the problem.

I am really glad that the big end donkey wrench or terminal crank case failure wasn’t mentioned - chain I can cope with….

Thanks guys – if anyone else has any suggestions feel free to post - while its apart I will have a look at all the other possibilities to make sure I cure it!

[richfzs]

Have a look at the front sprocket....

And you did order sprockets as well as the new chain, didn't you?

[Jamieg285]

Check the chain for stretch. Full details of how and what it should be are in the Haynes manual.


I had the same symptoms as you. Although the chain/sprockets all looked OK, the chain had stretched well beyond it's limit and wasn't fitting the sprockets properly.

[darrsi]

May be worth giving the chain a heavy lubing, it may ease things a little, but generally once you start getting sticky links they just get worse to the point of unbearable.

[Fazerider]

I had a similar noise a few years ago. I was sure it was the chain, though it wasn't worn and the clunk didn't seem to be present when I span the rear wheel with the bike on the centre stand.
After a couple of months (and a couple of thousand miles), I finally spotted a crack right across one of the side plates.
It was an inner one and I guess the gap closed up when the chain wasn't under tension, at least to begin with, which made it very difficult to spot.

[Skippernick]

It doesn’t happen in neutral or with the clutch depressed while moving and doesn’t happen when stationary. 

Can't be the chain then!!!!

[darrsi]

It doesn’t happen in neutral or with the clutch depressed while moving and doesn’t happen when stationary. 

Can't be the chain then!!!!

I'll give you stationary......but i'm hearing ya!

[Skippernick]

It doesn’t happen in neutral or with the clutch depressed while moving and doesn’t happen when stationary. 

Can't be the chain then!!!!

I'll give you stationary......but i'm hearing ya!

If it doesn't happen when he pulls in the clutch but is still moving it can't be the chain because the chain will still  be spinning!
Surely?

[Kentish]

Sounds like the main bearing to me.

[roadpilot3]

Just thought I would let you all know my problem is sorted 

New chain and sprockets have done the job, front sprocket was worn beyond recognition and it looked like I had been sent the wrong bit, no wonder it made all sorts of bangs and rattles - now it rides like new again and looks pretty cool as well!

Thanks for all the replies.

[darrsi]