[meekon]

Hi all, I’m very lucky to have the New Spectral 29 CFR and have noticed an issue pedalling with heavy load when in 4th/5th gear. It looks like since the chain line is quite extreme, the chain is interfering with the sprockets causing a clicking/ratcheting noise.

The gears are perfectly indexed, B tension correct etc and I’m certain it’s due to the angle the chain leaves the cassette in these gears to the crank.

Has anyone else experienced this (with Shimano 12 speed)? I’m wondering if the same would happen with SRAM drivetrains. I think this is caused but the 55mm chain line these bikes are designed around.

Many thanks

 

[BrianRidesBikes]

Hi, odd that it happens in the center of the cassette. Ruling out the obvious, it's a Shimano 12 speed chain and is facing the right direction?

 

[meekon]

Hi Merry Christmas! Yes is a Shimano 12 speed chain facing the right direction. I’ve tried Deore (shipped with) and a an XTR chain, both the same.

In 4th/5th, the chain is on quite an angle to the crank, it’s running a 55.5mm chain line (Raceface Cinch BB and Next SL crank) so pretty much spot on.

Anyone else with Shimano 12 speed and 55mm chain line (437mm chain stay or shorter) notice it?

 

[dudebro]

Slightly bent derailleur hanger?

 

[meekon]

I thought this, and it is bent/twisted but apparently all Shimano 12 speed mechs are. It’s indexed perfectly and silent when no load is applied so I think it’s ti do with the tension on the chain causing the links to ping off the sprocket. But surely it can’t be designed that way? Hoping someone has Shimano 12 speed with 55mm chain line and can confirm!

 

[korbzy]

I also had chain alignment issues with my 29" CF 9, there was a dull clicking noise and it was due to the chain guide rubbing and pushing my chain over(causing alignment issues). I had to remove a spacer in the chain guide and retune my gears.

edit mine is SRAM 12 speed

 

[meekon]

Hi, I had the same thing - I had to file down the spacer about .5mm and it stopped rubbing. It wasn’t causing alignment issues on mine though. Anyone else with a Spectral 29 and Shimano 12 speed?