Whirring sound from front sprocket (or so it seems) after a dead chain was replaced?

[Cortez]

Excuse the massive title.

I was just on a 1000 mi+ trip with my FZ6 S2 and figured out in the first 200
miles that my chain was shot (I know). A few links seized up after 2 hours in
the rain and I tried to loosen it up with some WD40 and motor oil after but not
much I could do, the bike was riding rough and surging.

I replaced the chain (which was stock chain, whatever that thing was) at my
destination and put on a new rear sprocket which was shot. The chain and rear
sprocket had 20k miles on them. Didn't have time to replace the front (which
was a JT 17 tooth replaced some 8k miles ago) on the same day.

The surging was gone, bike became perfectly smooth, BUT, the chain had a
very loud noise (figured it was a bit too tight at the time). I thought that maybe
the front sprocket was worn more then I thought so it didn't "fit" perfectly with
the new chain and THAT was the source of the whirring sound.

However, yesterday I cleaned up the front sprocket area (it was a nasty mess)
and went back from the 17T to 16T new sprocket (also JT) and the noise is
now even louder.

I can't hear it that much when I'm accelerating, but keeping a constant
speed between 20 and 50mph the bike sounds like a military transporter
(humvee) on offroad tires. I was told that there's a bearing up front near the
front sprocket.

Could that be 'shot'?

But again, I must point out that the sound didn't come on over time and
got louder - it was there INSTANTLY after replacing the chain.

Ideas are welcome, and I'll swing by a yamaha shop next week so that
they can put an ear on it too.

Thank you.

EDIT: Local dealer says that REGINA chains tend to "sing".

 

[FinalImpact]

How did you verify alignment? And it has ~2" (50mm) of slack in neutral?

 

[Cortez]

How did you verify alignment? And it has ~2" (50mm) of slack in neutral?

One yamaha dealership changed the chain and set the alignment, I looked at it
and it seemed fine. It WAS a bit too tight but not by much. I haven't checked
the slack yesterday, I will in the next 30 mins or so, it's been raining for a
while now.

Again, the alignment seemed fine after changing the front sprocket yesterday.

 

[Motogiro]

Also a source of noise could be mismatch of chain and sprocket sizes. Ex: a 530 chain with a 520 sprocket.

Dealers are always suspect when they work on your bike. Time and time again they fail on proper chain tension and wheel alignment. It may pay to check your cush drive at the rear spocket to insure all rubbers are present and I think I remember the OEM front sprocket on the FZ6 had a rubber mount?

 

[FinalImpact]

I won't jump and say this is a value added post per this thread, but look at the profile difference from the OEM (bottom) Sunstar 46T to the top Sunstar 48T. Both are 530's!
The 48T lost some contact patch at the teeth and interior lost some mass shedding weight from the core. It weighs about a 1/3 less than OEM part.

And yes, it sounds different too! Not loud, just different.

 

[Cortez]

Well, the chain was too tight.

Properly adjusted most of the sound went away, but the Regina chain has a
specific sound for sure, so, yeah, I guess everything is ok.

 

[Cloggy]

Well, the chain was too tight.

Properly adjusted most of the sound went away, but the Regina chain has a
specific sound for sure, so, yeah, I guess everything is ok.

Good to hear you got it sorted, I've had this once before, the dealer over tightened the chain, on my ride home I was trying to figure out where the sound was coming from, so at home I checked the play and there was hardly any. I took it back to the shop and got them to adjust it properly, and of course the noise had gone :thumbup:

 

[SAAVA]

I have the same issue with my new RK chain. After about a month and 3000 miles I have either gotten used to it or the sound has diminished. I did read somewhere else that someone suggested that many replacement front sprockets are the cause due to a lack of sound proofing issuing from the drive train. It really bothered me at first, but I guess I am adjusting now.

 

[Motogiro]

Dealers will rarely ever adjust a chain correctly. They will try to make you believe that the chain will stretch. It will loosen up when it has caused undue wear and damage to your bike.
You will never see a specification to set your chain to a specification that allows for stretch.
Set your chain to the service/owners manual specification!

Sent from my XT1254 using Tapatalk

 

[SandyN]

I am of the opinion that the whirring is the reason that the OEM front sprocket has rubber cushioning. I changed mine to standard steel and the whirring is definitely louder when I freewheel with engine off down my driveway into the garage.

I can also just hear it at 20 km/h, helmet on, visor open, no earplugs and leaning the bike to the right. Seems to be a bit softer after a chain lube.

I'm afraid I don't seem to be able to load a photo of both sprockets.

 

[Cortez]

I am of the opinion that the whirring is the reason that the OEM front sprocket has rubber cushioning. I changed mine to standard steel and the whirring is definitely louder when I freewheel with engine off down my driveway into the garage.

I can also just hear it at 20 km/h, helmet on, visor open, no earplugs and leaning the bike to the right. Seems to be a bit softer after a chain lube.

I'm afraid I don't seem to be able to load a photo of both sprockets.

If you'd read the original post again, you'd notice that the front sprocket was
already an aftermarket one, and was silent, but yeah, that makes noise too
even if it's a different kind of noise.

 

[Andz]

Que? Rubber mounted front sprocket?

I don't remember such a thing when I changed mine.

 

[SandyN]

The sprocket has rubber shoulders which cushion the higher parts on the links before the chain makes full contact with the sprocket.

 

[Andz]

Here's my original front sprocket, are you talking about the black bit with 5VX and 16T on it?

 

[SandyN]

Yes, that's it; I assume it has some cushioning effect to reduce noise?