Calle

I have a Haanjo Comp CX bike, 2x11, 46/36 11-32t Shimano 105 bike. The guide pulley is very noisey almost like a constant buzz saw. It shifts fine and is indexed. Its not anywhere near the cogs and makes the sound in all gears with big/big combos being worst. I have experimented with B screw tension, cleaned and lubes to no avail. The sound is from the chain coming off the pulley teeth..It is slightly bent but even when holding it straight the noise is still there. My other 105 group bikes are silent...question is what can cause this, what can fix it and how can i bend that guide pulley straight. This bike has 100 miles on it. Thx!

corrado33

Are you saying that the pulleys aren't in the same plane as the wheel? Meaning they're slightly bent? Get a derailleur hanger alignment tool and fix that first and foremost. The derailleur itself shouldn't be bent. If it is then well, it's time for a new derailleur. It's hard to fix a bent derailleur, that's why the hangers are made to bend first!

Secondly, clean and lube the pulley bearings/bushings themselves. Thirdly, loosen the bolt holding the pulley in place a tiny bit. They can often be too tight.

Make sure you have the correct pulley in the correct place. Pull them both off of the derailleur. Hold them by the side plates and move them laterally. The one with more play (the one that wiggles more) should go on top.

headasunder

I would be surprised if it was the pulley, swap it out with one off your quite bikes to isolate it (also try the noisy pulley in your quiet drive train). How old is the rest of the drive train? did the noise just appear or was a gradual thing

Calle

The bike has 200 miles on it tops, the noise has progressively worsening. It is not present in the small chainring. The jockey pulley and hanger pulley have different teeth profiles so I cannot swap them to check. Bike has never been dropped and I cleaned the chain properly after 100 miles.

trailflow1

Things to check

The wheel is fully seated
Skewer is tight
Side to side play in the cassette
Side to side play in the freehub
Hub lock nuts are tight
Cassette lockring is tight
Hanger is tight on the frame
Derailluer is tight on the hanger
The cable is clamped tight and in the correct position
Stiff link(s) in the chain
Damaged/Broken/Bent/Kinked chain
Bent hanger
Bent derailleur
Chainline
Loose chainring bolts
Loose crankset