Jockey wheels

[Fnaar]

Just been looking at my 'hack/commuter' MTB which is old but fully functional and takes me for miles and miles for commuting and short summer tours/jaunts. The jockey wheels are basically like ninja stars. Now, I have another old MTB which I'm gradually raiding for spares, and on which the jockey wheels are fine. Is it a straightforward job to transfer them from one to the other? Do I have to take the chain off? Is the number of teeth on the jockey wheels important?
Thanks in anticipation.

 

[GrasB]

Is it a straightforward job to transfer them from one to the other?

Yes

Do I have to take the chain off?

Depends on your mechanical skill but generally no. Best to remove the rear wheel so there's no tension in the chain.

Is the number of teeth on the jockey wheels important?

To some extent yes. You can genrally get away with +/-1t but beyond that things like the jockey wheels fitting the mech & the distance between the top jockey wheel & the cassette can cause problems.

 

[Fnaar]

Thanks GrasB

 

[HLaB]

I don't know is all wheels are the same but I replaced a broken one with one of an old deraileur a couple of nights ago (a 5600 jockey to replace a 5700), all that was needed was a small allen key (3 or 4mm I think).
It could be done I think with leaving the chain on but its easier IMO without.

 

[Cubist]

Another limiting factor is the width of the jockey wheel. I tried to raid an old Tourney mech for a jockey wheel to put on an Acera, but it was far too thick to fit. Otherwise, just a case of undoing one bolt and swapping the wheels over.

 

[Fnaar]

Mission accomplished, thanks all for your help and advice I was helped by the fact that the jockey wheels were the same. Still, a year ago I wouldn't have dreamed of trying it. Cycle Chat comes up trumps again.

-----------------------------------
Sent mobile phone stylee