Rear derailleur at angle to cassette

[Datopic]

Hi All,

I was testing my gears today and whilst checking the rear cassette I noticed an intermittent clicking sound when the chain was on the outermost sprockets (i.e., furthest from the spokes). On further inspection I noticed the clicking was being caused by the occasional collision between a sprocket tooth and an outer plate on the chain (before the chain fell into the correct place).

As I was about to check the gear indexing (with the help of a video on youtube), I noticed that rear derailleur was at an angle to the cassette. A picture is attached.

Can anyone see what the problem is, and whether it can be easily fixed? Any help would be appreciated.

 

[Globalti]

If the bike has falken over on the right hand side the hanger could have got bent inwards. Take it to an independent bike shop for checking, not a bike supermarket.

 

[Ajax Bay]

^^^^^ With the rear derailleur like that you will never get the gears working properly. The RD is screwed into a small aluminium peice of metal (hanger) which is itself screwed onto the frame drop out. It's like a fuse: designed to bend to stop possibly catastrophic damage to the frame. It needs to be vertical in the fore/aft plane ie looking from behind. You can bend it, with the help of a vice and not with the RD attached, but it is difficult to get right and the metal will weaken each time you do it. These hangers come in many, many various sizes and, if you take it to your LBS they should be able to identify and help - they may have just the right one in their 'box'. Otherwise they can order it - either way expect to pay £20. It's as easy to fit as it is to take off. Very clean cassette btw!

 

[potsy]

Mine looks a bit like that on the mtb (the angle not the cleanliness of the cassette ) and the gears are still working ok-ish.
Had two falls on it both times with the bike landing derailleur side down, must get round to sorting it one day.

 

[drummerbod]

The black hanger to me looks straight. It looks to me that the frame is bent just above the hanger on the inside where it looks crumpled.

In fact looking at it again it even looks cracked or it could be the paint flaking off due to the internal bending.

 

[Ajax Bay]

possible that the hanger has been bent

the frame is bent just above the hanger

Bit of both, probably. When I had exactly this issue with a 'rescue bike' I tried straightening the hanger; unsucessfully - it broke. I found a replacement at my second LBS, (a machined one) and fitted it but it still wasn't right; and as @drummerbod has surmised with the OP's frame, the rescue bike frame dropout had been bent, beyond saving (ally frame). As new hanger went back - swapped for inner tubes at LBS. Some of the removed bits now pressed into servie on other bikes: the frame was unrescued whence it came (local, excellent 'recycling centre').

 

[Datopic]

Thanks for all your responses.

After reading the first three responses I took it to a bike shop and the man said it was actually normal (this is assuming he understood what I said - I think I was clear). It's a BMC SLR02 (ultegra) if that makes any difference. He also tried the gears briefly and said it ran perfectly. It did seems to be running better, but I was unable to play around with it to demonstrate the problem I had observed because he was only using a very basic stand to hold the bike whilst checking it.

I agree that the frame and hanger both look to be at an angle. The frame isn't cracked as far as I can tell (see pictures). The paintwork is chipped, though, and I would say that some of the metal seems to have been chipped away somehow too.

I bought the bike new and have fallen over to the right once before but the bike was stationary (I wanted to see if clipping out of the pedals had become subconscious - turned out it hadn't!).

The bike is fine to ride, I'd rather just get any problems ironed out sooner rather than later.

Oh, and the cassette isn't so clean any more, sadly. ;-)

 

[Datopic]

Just for the benefit of anyone who finds this thread in a search:

I took the bike to another bike shop and they said that the derailleur shouldn't be at an angle and that the bike wasn't running as smoothly as it should. Signs of impact could also be seen on the derailleur. They used a tool to bend the hanger (and possibly the frame to a lesser degree, since they deliberately left it attached) back into alignment. Now it really is running perfectly.

 

[accountantpete]

My Ribble Gran Fondo was like that - so much so that the cage would clip the spokes when on the biggest sprocket.

It also made a noise from the lower jockey wheel/sprocket not synching properly.

As the frame is carbon and no sign of the hanger being bent I fudged a solution.

I undid the hanger slightly and placed a small piece of thin hard plastic in the gap between hanger and frame and re-tighten the hanger. This forced the hanger to lie at an angle more perpendicular to the road and straightened out the rear mech - job done at nil cost.

 

[RegG]

I had a similar problem with my Defy having had a 'clipless moment' - the hanger was very slightly bent but my very helpful and reputable LBS soon sorted it for me and the gears change smoother than they did when I bought the bike (from a different shop).

 

[Fnaar]

I had a similar issue a couple of years ago... turns out the hanger was actually broken... lbs took derailleur off to investigate (I was there) and the hanger just fell to the floor!

 

[raleighnut]

Just for the benefit of anyone who finds this thread in a search:

I took the bike to another bike shop and they said that the derailleur shouldn't be at an angle and that the bike wasn't running as smoothly as it should. Signs of impact could also be seen on the derailleur. They used a tool to bend the hanger (and possibly the frame to a lesser degree, since they deliberately left it attached) back into alignment. Now it really is running perfectly.

Even a new hanger needs to be aligned correctly after fitting.

 

[fossyant]

Oh the filth.....

Bent hanger/cage !!!