Rear derailleur problem

[Bax1980]

Hi, I have bought a new 2010 Trek 4400 but after while I noticed that my rear derailleur, Shimano Deore, hits the frame of the bike.

So my question is, is that normal or maybe there is something wrong with my derailleur setup, or is my chain to long? It is quite close to the frame, is there maybe something to put between the derailleur and the frame ?

[attachment=1756]

[nameused]

Did you buy it at a bike shop? If so it should have a warranty on it for free service for a year. You could just bring it back there and have them fix it for you.
If not, when does it hit your frame? Just riding around on the road? Or are you going off some jumps haha

[Bax1980]

Yeah, it was bought in a bike shop, and even went there and they said that that happens with Deore derailleur, which I did not believe. So I'm asking here does that happen to anyone else?

And it happens even when I climb the curb on the streets, you don't wanna even know what is the sound when I go off road.

[JohnnyCO]

One of two thing I think of. One, is the derailleur cage (long part hanging down with the two jockey wheels) bent in toward the wheel. It should be perpendicular to the ground. Second,the low limit screw is not set properly on the rear derailleur.

[cyclerUK]

Are you sure it's the dérailleur hitting the frame?
It's known that chains will hit the chainstay (chain slap!) and that's why there are chain guards fitted.
Such as:-
http://www.merlincycles.co.uk/Bike+Shop/Accessories/Bike+Accessories/Frame+Protectors/Lizard+Skin+Super+Jumbo+Chainstay+Protector_1977.htm

It's not normal for dérailleurs to hit the frame. Check the chain length as per Alex's tutorial on this site though..

[JohnnyCO]

OH, you said its hitting the frame, not the wheel. Read it wrong. Sorry. Is it screwed on correctly? Is the b-screw sitting in the right spot on the frame. Sometimes that can get pinched in the wrong spot when screwing on the derailleur. Check that low limit screw too.

[Bax1980]

Thx everyone, and thx JohnnyCO, yeah the one problem was in the low limit screw, the derailleur cage was slightly hitting the frame. But I think that is not the only problem because it still is quite noisy on small bumps. Sounds like rear derailleur is hitting something. Or in my opinion is wrongly put on or designed cause it still kinda stops hard when I jump or even climb the curb and it makes hard hitting sound. Down is the picture.

[nameused]

It looks like the derailleur is too close to the gears. Try adjusting the B-screw, which is the one that looks out of place on the top of the derailleur.



The gear on the derailleur shouldn't be touching the cassette.

[JohnnyCO]

When adjusting that b screw, you should have about 3-4 mm between upper jockey wheel(guide pulley) and the largest cog on the cassette. Have the derailleur in the lowest gear. While pedaling,just mess with that b screw until the pulley starts getting choppy. Then turn the other way till the chop is eliminated. Go ahead and measure. I would rely on performance than the measurement.