[ryan stewart]

Posting in general since, well, its not just 848s. But I have a 2012 Corse and the belts (which are only 2 years old) are horrendously loud (as loud as the termis) when cold. They just sound like belts but when I fire the bike up for the first time after sitting for days when its really cold (sub-50f) and take forever to quiet down. Once the bike runs for a while they shut up and then the rest of the day they dont get that loud again even after sitting for a couple of hours, etc, even if its still cold outside.

Wondering if its indicative of something I should be looking into. I mean I know belts do make some noise when cold (my cars serpentine belt does as well, etc) but man these are excessive when ice cold.

 

[Shazaam!]

Your first step is to inspect the belts for wear and the correct tension.

When a synchronous (timing) belt is tensioned, the belt stretches and the distance (pitch) between its teeth increases. When correctly tensioned to the manufacturers specification, the distance between the belt teeth best matches the fixed distance between the sprocket teeth. Under-tensioning will allow the belt teeth to ride up on the sprocket teeth causing wear of the material covering the belt teeth, and in extreme cases, allow belt ratcheting (tooth jumping). Over-tensioning also causes a tooth pitch mismatch, causing accelerated wear and additional frictional heat that also reduces service life. Both conditions exhibit increased noise.

Aftermarket belts have different construction and materials than the OEM Gates belts, so the tension specification that are correct for Gates belts are not correct for aftermarket belts. Use the tension specified by the aftermarket belt manufacturer.

 

[ryan stewart]

Ill try and dig in and do that shortly but anyone experience this specific scenario? They are quiet in the summer, quiet once they warm up, etc. Im wondering if the belts installed (I had Ducshop do them, RIP) are of a type that contracts a ton when cold.

 

[Buhgaboo]

Post a video

 

[ryan stewart]

Sorry for the delay, its been warm.

New video by Ryan Stewart

photos.app.goo.gl

Its not really picking it up all that well but its about as loud as the exhaust at idle and makes this high pitched whine. Its temp dependent, its loudest if I were to leave it outdoors like when I would setup at a track in the evening, leave it out where its like 35 overnight, and then come back to it to fire it up in the morning. Once outside temps get above 60 or the bike has been running for a bit it quiets WAY down. At temp or if its starting up when its 80+ outside it sounds juts like the serpentine belt on my car.

I don't ever rev it until a temp is reading (belts will be HALF as loud by that point) and never really whack it until the bike hits upper 60s (C) and by then the belts are quiet. And subsequent starts through the day are quiet as well.

Im wondering if they were possibly slightly too tight OR its just how they are when cold, like said at working temps they are barely audible. Bike runs like a top in all scenarios

 

[Buhgaboo]

I'm not hearing anything definitive...sounds normal or possibly a bearing...belt noise comes across as a harmonic...a vibrating rubber belt...it's clumsy and audible as a wooshing sound especially when it's hot...the sound seems crisp...it's easier to discern giving it some revs..
. A flutter;belt...a whine;bearing...loosen the belt by 5 hertz and see if it changes

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