noisey 105 chain ring

[WindyRob]

i have a triple 105 9 speed set up on my bike. the middle chainring has what appear to be 4 small blades that sit just below the teeth. the chain clicks against these blades with each peddle , i.e. 4 times a revolution. it is not a particularly loud noise but as i'm sure you can understand it is really beginning to P!$$ me off

does anyone know:
a) what the blades are for
if i change to a shimano chain from the high end SRAM 9 speed chain i have will this stop the noise

any advice much appreciated :?:

windy

 

[rustychisel]

I cannot visualise these wings of which you speak... post a photo? They could be to stop the chain jamming between chainrings (upper and lower), are they pegs, or shaved section of a wider chainring? If they're fouling the chain something ain't right (but you knew that already).

 

[Monty Dog]

I've already posted a reply on 'the other forum' to your question, but the blades are there to help the up-shift from smaller to bigger chainring - without them, the shift would be far more sluggish. Normally, they wouldn't touch the chain when engaged to the chainring - are you sure your chain isn't excessively worn and therefore touching these 'blades'.

 

[WindyRob]

thanks i suspected that they were to assist with the changing between chain rings particularly when the gap between teeth numbers is large; i.e. 30 to 42 as i have.

bike is only a month and half old. it was an ex-display cyclosportif model from thorn, i think that they made the bike up to show as a fast Audax model as the seat and guards are definitely for long distance rather than racing....

the bike was originally shipped with an 8 speed chain which was as noisey as hell, SJS swapped it for the top end SRAM 9 speed chain, it is now much quieter but on the middle ring with the blades it clicks. the real answer i'm looking for is does anyone run the same 9 speed 105 group but with a shimano chain and if they do does it click?

Windy

 

[littlestwoo]

Get back in touch with SJS.

I don't run shimano (I use that italian stuff!) but a 9 speed chain is a 9 speed chain in terms of Shimano and SRAM, when I did run shimano I would always use SRAM due to better durability.

SJS need to suggest a fix for you, which shouldn't cost you any money. It could be a faulty chain ring with the ramps (wings) sat a little pround or something like that. If this was a bike out of warranty, careful inspection might suggest the need for a little bit of filling to the ramps.

Steve

 

[Monty Dog]

Is the chain noisy in all gear combinations? Are you running a double or triple chainset? Is it just noisy when in the small rear sprockets and the inner chainring? Sounds like you're running the chain in cross-over as above and it will be noisy - solution is not to run the small sprockets in the small chainring - shift it onto the big chainring instead. Changing the chain is unlikey to make any difference. I think it's highly unlikely that it's anything to do with components/bike set-up.

 

[WindyRob]

it's a triple and i avoid at all times running the extremes of the gearing even on the middle chain ring. i'll call SJS they have been good with the other questions etc that i've had re the bike.

Windy