Loud Tapping Noise and Low Fuel Economy (2012 Glee)

[allabright]

Hi All,

I've noticed a worrying noise coming from my 2012 Glee.

- No noise when running at idle, or revving the bike in neutral (so not the engine?)
- Worst in gears 1, 2, and 3, at lower revs.
- Loud tapping at maybe 3-4 times per second, coming from either directly below me, or from the back end.
- Can feel it through the footpegs.
- Fuel economy has gone down from ~55 mpg to ~45 mpg.
- Bike is at 62k miles, service and MOT just done a month ago, everything but valves.

Any idea what this could be? I thought it may be the drivetrain, as the sprockets and chain are looking reasonably worn (done about 20k miles year round in all weathers) but surely this would have been flagged at the MOT? Am I OK to keep riding it until it's sorted, or should I stop and get it into the shop ASAP?

[kwackboy]

Sounds like maybe the chain has a tight link or you have missing teeth on your front sprocket.

[The Doctor 46]

I'm no mechanic my friend but if that was my bike I would have it looked at very soon and only ride it to the closest mechanic. I hope it's not something really serious and maybe just the chain and sprockets. Good luck 

[Barbel Mick]

I'm with kwackboy, a tight/seized chain link? I'd also check the wheel bearings too.

[Brockett]

How would an MOT discover this when it only happens when driven in gear?
Has this noise arisen gradually or all of a sudden?
I had an 'all of a sudden' noise that clacked up and down with the speed of the bike. Turned out to be a six inch agricultural nail with 3 inches poking out of the rear tyre.
A seized link, if seized in-line with the top or lower run, will be hard to spot until it tries to go around the rear sprocket.
Could be a dozen or so other things so be sure to let us know when you find out.

[Dicky]

I had similar on my 2004 DL650 though it was a clicking noise rather than loud tapping which disappeared when I lubed the chain. Chain and sprockets all looked good but when I attempted to pull the chain back from the back sprocket at the 3 o'clock position I could see daylight between the chain and sprocket. Closer inspection of the chain revealed rust on a couple of links suggesting that the O rings had gone. I changed the chain and sprockets and the problem was solved.

[allabright]

Thanks all. I will lube the chain tomorrow before my ride into work and see if the noise dies down at all. I will also run the chain round the sprockets a few more times to see if I can find any tight spots. to be honest the chain is quite rusty and well-worn, but trying to pull it off the back of the rear sprocket I couldn't get any movement at all. That may just be because it's tightened up. Either way it's probably due a replacement after ~20k miles so I will likely start there. Thanks.

[allabright]

I think I may have found something that could be the issue.

The noise seems to be coming from the front sprocket skipping slightly as the chain goes round, as in the video here (around 00:10) https://photos.app.goo.gl/sCg3CAbXGR26VzhF6.

Is this normal? And if not, what would it indicate?

The wheel also seems to be very tight. If I spin it with my hand it seems to reach a tight spot and stop before going round fully. I'm not sure if that is the chain or something in the transmission. I haven't ridden it today as I don't know how safe it is.

Thanks.

[Mark Shelley]

Your chain and sprockets are f****d.

[Mark Shelley]

Actually, watching that again, I suspect your chain is also too tight. When you adjust a chain you need to rotate the wheel and check the slack at its tightest point.

[allabright]

Quote removed

Yeah I thought that too. They adjusted it at my service/MOT, but it did seem tight.

I've added a couple of videos of the banging noise to that album too. Do you think it's as simple as chain and sprockets? Or does that sound like something worse? I have ordered the chain and sprockets yesterday, so will replace them and see if it improves the sound.

[Rixington43]

The banging could just be the chain lashing between the power pulses of the engine, mine does that a bit when I run it in lower gears on the centre stand. Being worn and tight will be making it worse though. Check for slack in the cush drive rubbers or sprocket carrier bearing wear though as both can lead to banging sounds from the rear hub.
Your chain definitely looks too tight and very possibly beyond it's optimum life, I'd say 20k isn't bad to get out of a driveline. As others have said, find the tightest point and set the slack to the minimum there.
If/When you replace them, I'd recommend the extra couple of pounds on the rubber damped front sprocket, it quietens things down a lot and is I believe what Suzuki originally fitted.

[Ianmc]

   If the chain has been tight for a while,have a close look at the rear sprocket bearing,it is a bit of a weak link in the drive assembly in general.
   I have just watched the video and seen that the front sprocket is pointed and the chain has flats worn on the inside.I am afraid it is WELL past its best.

[Dicky]

My old chain sounded like the one in your video, though the clunking noise was not as pronounced as yours. I replaced all the rear wheel bearings at the same time as I replaced the chain and sprockets as a belt and braces approach and as the wheel was off anyway....... The difference in ride quality was worth the minimal effort.