Rear Derailleur Movement Blocked by Frame


Über Member
I've just been given an old bike which i thought I could get working.

The chain was actually snapped, so I managed to get it fitted again and borrowed a friend's chain tool to close it.

I repaired a puncture on the front and was all set to give it a try.

The rear gears don't change .. on closer inspection, there is a lug on the frame which is in the way .. see picture attached.

What is the solution please?




Legendary Member
Accra, Ghana
What you've got there is a very cheap and basic Shimano derailleur which is meant operate in a drop out without an attached hanger which is what you've got on the frame. The U mount at the top acts a hanger.
Better derailleurs have a screw at the top pivot which locates into the hanger.


Can you see the Allen key bolt at the top which screws into the frame mount?
So your options are buy a new better derailleur or just saw off the hanger mount.
In your pic the U mount is not fixed fully in the dropout so try pushing it down so it located correctly first. The screw at the top should locate in the top of the dropout to stop it moving under load.
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Über Member
Thanks for the reply, I see what you mean now

It's not really a big deal, an elderly neighbour asked if I wanted the bike so if if needs dumped, so be it.

I actually have a Raleigh Equipe 'racer' which does me just fine. had my first racer, aged 12 (1970) .. a Carlton

Ian H

I am an ancient randonneur, & I often stop for tea
East Devon
As above the 'lug' you mention is a mounting point for a derailleur. Check it still has usable threads. Your derailleur is mounted wrongly. You have screwed it into a mudguard or rack eye. If you remove that screw and reposition the slot so that it's parallel with the dropout, you might just get away with your current setup. Otherwise, assuming the threads are okay, buy or find a new derailleur to mount on the 'lug'.


Eh up
As suggested by @Cycleops undo the quick release and shove the derailleur down until it hits the axle.
Alternately bolt it to the derailleur mounting lug, it may work.
I would buy a better derailleur that fits the lug rather than saw it off.


Deplorable Brexiteer
Even I'm willing to pay that much for a fit for purpse rear mech. Free bike and a £5 repair, still makes for a cheap project! :laugh:


I don't think there's necessarily anything wrong with the derailleur, just mounted in the wrong place.

You need to take the wheel out, then the derailleur goes into the dropout, you will see that the special shape nut will slide along the dropout, all the way to the back, tighten the screw, wheel back and you should be done.


The dropout hanger is not flat to the dropout and is canted out. The mech hanger will not sit flat and will foul the dropout hanger. That’s why it’s been mounted behind it at the moment.


The derailleur he has in the photo can not be mounted in the hanger.
No its the abomination in question!:laugh:

its not designed to fit on that frame, it has an integrated hanger to fit on hangerless frame. Abomination may be too strong, but its cheap old SIS stuff, rather than a nice vintage one.


But if that derailleur ever worked - then the above is how it must have been. I'm assuming it worked at some time in the past, which means there must somehow be just space for the integral hanger and the mech to coexist.

Of course, it could be they are just random components and it's never worked and those components can't coexist. Then the only option is a mech bolted directly to the integral hanger.
There is. My commuter has an integral hanger, but when I bought it (n hand, many years ago) had an sis derailleur like that on the dropout, and worked perfectly fine.
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