Wobbly rear mech body

[Eric Olthwaite]

While fettling today, I noticed that the part of the rear mech surrounding the bolt that screws onto the mech hanger (which I think might be called the B-knuckle?) wobbles a little against the hanger when I grab the body of the mech and wiggle it; even though the hanger bolt is tight.

I've never noticed this before, I had kind of assumed that this part of the mech would be stiff against the hanger.

Is the wobble normal? Or is there something wrong?

 

[Ming the Merciless]

Sounds like something not right. Are you able to share a video if it wobbling?

 

[Eric Olthwaite]

Hmm. I've taken a video - but can't work out how to upload it here!

 

[Ming the Merciless]

Hmm. I've taken a video - but can't work out how to upload it here!

Put it on YouTube and share a link

 

[Eric Olthwaite]

OK dinner now so will have a go tomorrow - thanks

 

[BianchiVirgin]

Definitely not right. That sounds like a knackered derailleur. That should only swivel and not wobble other than to tiny tolerance.

 

[Eric Olthwaite]

I feel all tech savvy now...

Wobbly mech on Youtube

 

[iluvmybike]

Check that the rd hanger is secure in frame and then check the rd bolt itself is snug. If still sloppy then it is getting worn

 

[si_c]

That's a steel frame with an integrated hangar, and you can see it doesn't move. Looks to me like the main pivot on the derailleur has got some slop in it - hence the wiggle.

You may be able to fix it with a derailleur service - see here - if not then a replacement derailleur is your best bet.

 

[Eric Olthwaite]

Thanks all, yes it is a steel frame with an integrated hanger. The service looks a bit scary but things are clearly not right so I may as well give it a go.

 

[si_c]

Thanks all, yes it is a steel frame with an integrated hanger. The service looks a bit scary but things are clearly not right so I may as well give it a go.

Worst case scenario you need to buy a new derailleur, which you would need to do otherwise anyway. Best case you make it work as normal, so nothing to lose by trying really.

 

[CharleyFarley]

While fettling today, I noticed that the part of the rear mech surrounding the bolt that screws onto the mech hanger (which I think might be called the B-knuckle?) wobbles a little against the hanger when I grab the body of the mech and wiggle it; even though the hanger bolt is tight.

If the head of the bolt isn't tight against the mech, would a washer on the bolt make it tight? Did you remove the mech and lose a washer?

 

[Eric Olthwaite]

If the head of the bolt isn't tight against the mech, would a washer on the bolt make it tight? Did you remove the mech and lose a washer?

Worth a go...