Jockey wheel alignment

laurence_cooley · Post by **laurence_cooley** » 03 Feb 2013 17:28

After cycling behind me today, James mentioned that it looked like my chain was rubbing the side of my derailleur cage. On close inspection, it looks like the jockey wheel is running off-centre. Any ideas why this might be? I'm wondering of the derailleur is out of line, or if it's a problem with the jockey wheel itself.

I tried to take a photo (not very successfully, but hopefully you can see what I mean).

Philip Whiteman · Post by **Philip Whiteman** » 03 Feb 2013 17:30

Laurence, sorry the picture is not visible.

Jockey wheels do wear out. They are not too costly or difficult to replace.

laurence_cooley · Post by **laurence_cooley** » 03 Feb 2013 17:32

I think I've fixed the photo.

I was thinking of just replacing the jockey wheel, but it occured to me that the chain might be running perfectly straight and it's the position of the derailleur that's out.

George · Post by **George** » 03 Feb 2013 17:40

My guess: either the cage is bent (and the jockey wheel is being pulled to the side in consequence) or the jockey wheel's bearing has disintegrated.

chris ankcorn · Post by **chris ankcorn** » 03 Feb 2013 19:04

George wrote:My guess: either the cage is bent (and the jockey wheel is being pulled to the side in consequence) or the jockey wheel's bearing has disintegrated.

The cage looked fine. Its more likeley to be the jockey wheel bearings.
All the jockey wheels I've pulled apart have plane bearings with a stainless steel lining/tube. I'm wondering whether it was assembled without this??

laurence_cooley · Post by **laurence_cooley** » 03 Feb 2013 19:30

There's quite a lot of lateral play in that one, which I presume there isn't supposed to me. I took it apart, cleaned it and reassembled but it's still possible to wobble it a lot by hand, so I think it needs replacing.

AlanW · Post by **AlanW** » 03 Feb 2013 19:40

laurence_cooley wrote:There's quite a lot of lateral play in that one, which I presume there isn't supposed to me. I took it apart, cleaned it and reassembled but it's still possible to wobble it a lot by hand, so I think it needs replacing.

There should be play in the top jockey wheel, but not in the other one. This is so that the jockey wheel can shift the chain from one sprocket to the next, hence why you need this lateral movement.

A point to note that most if not all after market jockey wheels do not allow for. Which is why I tend to purchase genuine Shimano ones to get the best shifting action.

THIS might help you?

laurence_cooley · Post by **laurence_cooley** » 03 Feb 2013 20:03

Thanks Alan. I've just ordered a pair of Shimano ones. Hopefully that will solve it.

Pedlo Mudguardo · Post by **Pedlo Mudguardo** » 03 Feb 2013 20:40

It might just be the photo but as someone who spends most of the working day looking from that exact viewpoint I'd say the cage looks decidedly bent. It would seem that the jockey wheels are keeping the correct line but the cage certainly isn't .

laurence_cooley · Post by **laurence_cooley** » 03 Feb 2013 21:12

Putting a ruler against the left hand (from this view) edge of the cage says that it's straight there. The right hand edge clearly curves in towards the bottom, but I'm not sure if this is how it's supposed to be or not (it's Shimano 105 but I can't find a rear view online to compare it with).

George · Post by **George** » 03 Feb 2013 21:18

Laurence, what I was suggesting was that it might be bent relative to the parallelogram. The side plates that reach down from the parallelogram may be straight, but the angle of those side plates relative to the parallelogram looks odd to me, as if maybe at some time it had received an inward bash from the side (e.g. in a fall). But, in all honestly, I'm not really sure; I'm just speculating.

laurence_cooley · Post by **laurence_cooley** » 03 Feb 2013 21:35

I guess that's a possibility, although I can't recall it taking any impacts. I'll see how it fares with a new jockey wheel and if that doesn't fix it, investigate further.

Clive · Post by **Clive** » 03 Feb 2013 22:00

I see Hope now manufacture Jockey wheels that have roller bearings, does anyone have experience of these?

If anything like other things Hope, they will be the canine's whatsits

http://www.hopetech.com/page.aspx?itemi ... escription

They (non Hope ones) are relatively inexpensive so I always renew jockey wheels when changing cassette, chain ring and chain.

AlanW · Post by **AlanW** » 04 Feb 2013 08:01

Pedlo Mudguardo wrote:It would seem that the jockey wheels are keeping the correct line but the cage certainly isn't .

Laurence,

Just as a matter of interest, is there any play on the actual mounting bolt where the rear mech attaches to the frame? Because as Nic says, it seems from the photo that the jockey wheels are taking up the bad alignment of the cage.

laurence_cooley · Post by **laurence_cooley** » 04 Feb 2013 09:08

The mech seems pretty solidly attached. When I shift into the small chainring, the line of the chain changes a bit so that it's no longer right up against the cage, so perhaps we're reading too much into the line of the chain in this photo.