ajl5126

This might be a weird question: I just bought a Miyata 110 today. The guy I bought it from said he had just had a new rear derailleur put on over the weekend. I rode the bike home, no problem but on the second ride I got about four blocks, went over a small bump and the chain popped off. I stopped to put it back on, and lo and behold the lower pulley had snapped off. I managed to find the pulley, but not the bushing, so now I need to replace SOMETHING at least. Not being an experienced bike mechanic, I started looking up what I needed to get, and that's where I started coming across problems:

1) From what I've read, the top pulley should say "G-Pulley" and the bottom should not. This was the bottom pulley, and it says G-Pulley.

2) Most places where I've seen the pulleys for sale individually, I can't tell if it comes with the bushing and whatever other parts are needed for it be attached.

3) This is the big one: It's an Acera derailleur, which apparently is a MTB derailleur for a 7 speed cassette. My bike is a road bike with a 5 speed rear cassette.

So now I don't know what I should be doing: Should I be looking for a new lower pulley? Should I be looking for a new upper pulley, and switching it with the one that is the lower position now (due to problem 2)? Should I be looking for a whole new derailleur for a road bike (due to problem 3, and also b/c I know this is a cheap derailleur and it might be easier to just replace it regardless)? Or should I just scrap the derailleur and turn this into a single speed conversion (which I was planning on doing at some point, but was hoping to get some experience working on the bike beforehand so I would be better prepared and know what I was doing)?

Any advice? keep in mind I'm a relative novice. And sorry if this isn't the right thread.

oldskoolwrench

First off, a couple photos of the rear derailleur would help to see just exactly what's going on.

The Acera rear derailleur will work fine with your current setup. It sounds as if the lower pulley came apart,
and if the bushing is missing then you're also missing the mounting bolt that holds the pulley in place.

My best suggestion is to dismount the derailleur from the frame, take all of the parts you do have and head to
your local LBS. They will be able to match up the parts you're missing in order to get the derailleur functional again.
Pay close attention (read: look at some bikes on the floor) to how the chain runs through the pulleys. Take the
derailleur home, re-mount it on the bike and get the chain run through the pulleys. Adjust the cable tension and
you should be all set.

If you're not sure of what to do, spend some time beforehand looking at "how to install a rear derailleur" at various
websites. From where you stand right now it's an easy fix; with a little time and patience you should be back on
the road.

Mos6502

Taking the dérailleur off might be an ordeal if they're using an old chain without a master link.

IF they can get the bike to a shop they can just point out what part they need and then take the bike back home and install it themselves. They're not obligated to have the shop do the repair.

wrk101

Head to a bike shop, easy repair, should not be very expensive. That derailleur will work fine on your bike.