Rear Suspension Noise

[Guest alexm3388]

Hi guys,

 

I have an NC750 DCT with 4500km on the clock. I've been perfectly happy with it for the past eight months and had no problems so far. However, in the past 10 days or so there is a "cluck, cluck" noise coming from the rear suspension. I know that "cluck, cluck" reference to it sounds quite stupid but I don’t know what else to call it. Most importantly, it happens only when you roll the bike forwards and backwards for a few meters and with the engine off, in neutral or in gear regardless. I bought the bike new and from the first day everything on it was completely quiet, not a peep from it until, like I said a few days ago, I noticed it while reversing the bike out of the garage. The sound is regular or consistent rather. In other words, if you roll it faster it will "cluck" faster, if you roll it slower the "clucking" is slower. In all honesty, the sound is not really loud and not very offensive but it's there nonetheless, indicating some kind of resistance being present somewhere. I mind you, I can hear it only at the rear, with the engine off and while rolling it forwards and backwards while I sit on it. Riding it on the road doesn’t produce any noise and the bike is not uncomfortable in any way. Why I suspect the suspension / torsion is because if I lift the bike on the paddock and spin the rear wheel, its completely quiet. You can hear it only when the bike rests on its suspension and when there's weight on it. I'm just curious if any of you had any problems with the suspension and if anyone had to take their bike in because of something like this. Yes, the bike is new and still under warranty but to take it to the dealership for inspection is time consuming and a hassle. Eventually, if nobody has any ideas I will have to take it in because it worries me, I don’t want it falling apart under me.

 

Thanks a lot everyone and happy motoring.

[Guest nigel w]

Hi Alex,

This sounds very much like chain noise, you say you can hear it when you sit on the bike moving it back and forward. At this time the chain will be tight as the bike has your weight on it, when you have it on the paddock stand the chain won't be as tight.

Get it checked out by your dealer but you may just find giving the chain a good lube may fix the noise.

Good luck

[Tex 36,817]

Hi Alex,

This sounds very much like chain noise, you say you can hear it when you sit on the bike moving it back and forward. At this time the chain will be tight as the bike has your weight on it, when you have it on the paddock stand the chain won't be as tight.

Get it checked out by your dealer but you may just find giving the chain a good lube may fix the noise.

Good luck

Agreed.

[bikerbampi 542]

Disagree!!!

I have just noticed it on mine with about 2800 miles. It happens when I am pushing the bike not sitting on it. Like has been said it is not loud and is not noticeable when the engine is running I haven't tried it on a paddock stand yet to see exactly where it is coming from but will do so in the next few days and report back.

[Guest nigel w]

Disagree!!!

I have just noticed it on mine with about 2800 miles. It happens when I am pushing the bike not sitting on it. Like has been said it is not loud and is not noticeable when the engine is running I haven't tried it on a paddock stand yet to see exactly where it is coming from but will do so in the next few days and report back.

I am quite willing to be proved wrong but in my mind suspension will only come into play with an up and down force, not moving the bike back and forth. I find this time of year when bikes stand and its very cold oil and grease become dry and tight, the chain sticks on the sprocket as it turns. My money is still on the chain!

Plese let us know if its something different I'm allways willing to learn.

[fred_jb 10,269]

I had a similar thing on my CrossRunner and it turned out to be caused by tight spots on the chain, and disappeared when I fitted a new chain.  Like you, I only heard this when paddling the bike into or out of the garage, though I could feel it when turning the wheel by hand with the bike on the centre stand.

 

Fred

[embee 7,288]

As the other say, as described the chain would be the suspect, but you'd expect the noise when it's on the stand too if it was simply stiff links.

 

Could it be the caliper? They have one close fitting pin and one "loose" pin in the sliding arrangement, and if you get hold of the bleed nipple and lift it up and down it moves quite a bit, which if the pads are just clipping the disc they will tend to do this. Could this be the "cluck" you hear?

 

The only other thing I can think is the cush drive which links the sprocket to the wheel, though very unlikely at low mileage/kms.

[trisaki 2,029]

Put bike on a stand then push hard on rear brake pedal release and see if wheel is stiff to turn / if it is then caliper needs a good clean up and grease / also turn wheel and grab hold of chain links looking for seized links tight spots etc _ could if able to strip and decrease suspension linkage as often from the factory no grease applied

[South 24]

My Gladius developed a clicking from the chain after having new tyres fitted.

Caused by the "mechanic" putting the rear wheel back on out of alignment, He'd left the adjuster loose on one side of the swinging arm.

Put it straight & the noise disappeared.

.

[trisaki 2,029]

Should read recrease suspension not degrease

[Guest alexm3388]

I am quite willing to be proved wrong but in my mind suspension will only come into play with an up and down force, not moving the bike back and forth. I find this time of year when bikes stand and its very cold oil and grease become dry and tight, the chain sticks on the sprocket as it turns. My money is still on the chain!

Plese let us know if its something different I'm allways willing to learn.

 

Hi Nigel,

 

Thanks for your reply. I checked the chain already plus, I lubricate it even more frequently than neccesary since it's been raining for the past two months almost daily. With regards to the cold that you mentioned, I'm in Africa, mid-summer. Also, i'm not sure about the tight spots on the chain- I covered only 4500 km or 2800 miles with it since new.

 

Murray,

 

I'll check the caliper, however, shouldn't I hear the pads clipping the disc while the bike is on the stand and the rear wheel is spinning?

 

Thanks a lot for your input guys.

[Guest alexm3388]

Put bike on a stand then push hard on rear brake pedal release and see if wheel is stiff to turn / if it is then caliper needs a good clean up and grease / also turn wheel and grab hold of chain links looking for seized links tight spots etc _ could if able to strip and decrease suspension linkage as often from the factory no grease applied

 

Hi Mark,

 

how do I strip the suspension linkage? Your idea about the lack of grease sounds valid.

 

Thanks.

[Guest nigel w]

Hi Nigel,

 

Thanks for your reply. I checked the chain already plus, I lubricate it even more frequently than neccesary since it's been raining for the past two months almost daily. With regards to the cold that you mentioned, I'm in Africa, mid-summer. Also, i'm not sure about the tight spots on the chain- I covered only 4500 km or 2800 miles with it since new.

 

Murray,

 

I'll check the caliper, however, shouldn't I hear the pads clipping the disc while the bike is on the stand and the rear wheel is spinning?

 

Thanks a lot for your input guys.

With reference to the weather lucky you, it's bordering on freezing most days here at the moment.

good luck with sorting your problem out.

[Guest Neil700]

Hi Alex. Like the others have said, I too suspect either the chain or chain adjustment. Stripping and greasing the rear suspension linkage is pretty straight forward and requires no special tools, however, you will need a centre stand and a block of wood to place under the rear wheel. I did mine about 3 months ago and it completely transformed the ride.

[Guest alexm3388]

Hi Alex. Like the others have said, I too suspect either the chain or chain adjustment. Stripping and greasing the rear suspension linkage is pretty straight forward and requires no special tools, however, you will need a centre stand and a block of wood to place under the rear wheel. I did mine about 3 months ago and it completely transformed the ride.

 

Hi Neil,

 

I appreciate your suggestion. Could you please explain the process of greasing it up if you dont mind since I'm not familiar with it. My bike doesnt have a centre stand but I have a paddock. However, I think that lifting the rear with a paddock and putting the bike on a centre stand are two different things, I might not come right. Maybe there's a workaround. Or maybe I'm just plain wrong, paddock might work out.

 

Thanks a lot for the help.

[Tex 36,817]

Look at the machine on the paddock stand - and then try and visualise what will happen if you remove a shock bolt!

 

It sounds, to me, as though the chain is too tight. Or has a 'tight spot'. Who last adjusted the chain? Did they check for tight spots when they did it? Checking for a tight spot - all chains can have one, even from new - is easy. With the bike on the stand, at a point midway along the lower run of the chain move the chain up and down and note how tight/slack it is. Rotate the wheel slightly and check again. Keep doing this until you've checked the entire chain. Almost certainly one part of the chain will be tighter than the rest. This is the tight spot. Now, set the adjustment so it is right at that spot. If you don't, and set the adjustment at a looser point when the tight spot comes round it will be too tight!

 

The noise can only be coming from a rotating part - chain, sprocket(s), disc, wheel.

 

Good luck.

[glencoeman 129]

I had exactly the same issues on a BMW 650GS a couple of years ago. Turned out to be that the rear chain sprocket had become hooked. If you feel a tooth on the sprocket between your thumb and forefinger and feel a ridge on the tooth, then that is what the problem is. The chain is actually getting stuck on the ridges. Only solution is a new set of sprockets and chain.

[Guest robin]

I think it's the pads moving back and forth in the calipers.   If you move back the pads move forward just enough to click.  Same when you change direction and go forward.

 

Nothing wrong Don't worry.

 

Get it checked though cause it's still under guarantee!!

[Tex 36,817]

But my understanding of the OP is that the clicking is repeated as the bike moves along. Pads will only cluck once!

[Guest Neil700]

Hi Alex. My advice is to buy a centre stand ( I bought a SW Motech online from bike gear here in SA and it is brilliant and very useful for maintenance and well priced too ). If you give me a shout, I would be more than willing to give you a hand with cleaning and re-greasing your linkage bearings. I am an accountant by trade but have a huge distrust of dealers ( was a 2X BMW owner, snuff sed) so do all of my own bike servicing, warranty or not. Cheers Neil

[Guest alexm3388]

Hi guys,

 

I really appreciate all of your inputs, however, I think push came to shove- I'll have to take it in. The more I listen to it the more it sounds like the gearbox and not the rear suspension. I recorded the clunking this afternoon and posted it on YouTube for people to use as a reference in case they struggle with something like this.

 

Here is the link to the audio file, I think you might find it interesting: https://www.youtube.com/watch?v=A_c3lIZkuiE&feature=youtu.be

 

Like I said, I will take it to the dealership within the next few days and will post the result here when I'm done.

 

Thanks a ton.

[Guest nigel w]

Alex that sounds very much like a tight chain.

[Guest alexm3388]

Alex that sounds very much like a tight chain.

 

Nigel,

 

Now that I think of it, you might be right. You reminded me of my old Honda CBX250 and the chain that I tightened too much. After releasing it, it was a different story.

 

Just, how the heck did that happen, It's basically new. I'm off to the garage to have a look.

 

Thank you.

[Guest nigel w]

When you come to check your chain, first check that the rear wheel is running in line evenly adjusted both sides. Check that the rear wheel axel is tightened to the correct torque.

Put the bike on the side stand then check the measurement of slack half way along the lower section of chain, you want between 30 & 40mm (I set mine at 40mm) then move the bike forward a couple of feet/metres and check again, adjust if required.

Then check the slack again.

Hope this helps.

[Guest alexm3388]

Well, that's one mystery solved. The chain has a zero slack when I sit on the bike, I just didnt think of it. Kept checking while I'm crouching next to it and it's not my first bike or the first chain.

 

Nigel, thanks brother and I thank everyone else for their advice. Although I have all the tools neccessary for this operation I think I'll take the bike in anyway tomorrow morning since it is still under warranty. If I mess something up I might loose it. By the way, does anyone know what is the torque required for the axle nut? Just in case...