Chain going beside rather than round lower jockey wheel - why / how fix?

For discussions about bikes and equipment.
User avatar
frank9755
Posts: 885
Joined: 11 Oct 2008, 10:38am
Location: London

Chain going beside rather than round lower jockey wheel - why / how fix?

Post by frank9755 »

My chain keeps coming off the lower jockey wheel and running through the cage beside it rather than on it.

I noticed this a few months ago and replaced the jockey wheel, which was very worn, and assumed that it would fix it. Maybe it did or maybe I didn't look closey. Either way, I notice the other day that it is happening again.

I went to the LBS and they suggested that I change the hanger. I did, but it is still happening. Within a couple of minutes of me putting the chain back on the jockey wheel it will have slipped off, especially if I shift a couple of times.

It's not clear what is going on. Nothing looks massively out of alignment but it must be or it wouldn't keep happening. The cage could have got bent, but I don't know how as I don't recall any incident.

I've ordered another set of new jockey wheels as simpler than messing around with the cage and maybe the ones I fitted have had issues - but not massively confident that they will fix it.

Any other thoughts / suggestions?
User avatar
Mick F
Spambuster
Posts: 56349
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by Mick F »

Sounds like you're using the wrong chain for the rear mech, or the wrong rear mech for the chain.
There shouldn't be any room for the chain to come off the lower jockey wheel and it to run alongside.
Mick F. Cornwall
User avatar
Audax67
Posts: 5999
Joined: 25 Aug 2011, 9:02am
Location: Alsace, France
Contact:

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by Audax67 »

I had this on an Ultegra RD with an Ultegra chain that was definitely the right one. Caused by too much crud building up on chain and jockey wheel. I switched to lubing my chain with wax and PTFE in a slow cooker. Been perfect ever since. See:

https://youtu.be/953QTThT4_M and https://youtu.be/HHr9znwpwmQ

It's a bit of a faff but I only need to do it every 600 km - and everything stays clean.
Have we got time for another cuppa?
User avatar
Mick F
Spambuster
Posts: 56349
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by Mick F »

I still don't see that it's even possible to run a chain alongside the bottom jockey.
Mick F. Cornwall
User avatar
Mick F
Spambuster
Posts: 56349
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by Mick F »

Here's one of mine.
Difficult to photograph unless I get the bikes on the stand perhaps.

Tried to lift the chain off to put it to the side, and it won't go.
IMG_0683.jpg
Mick F. Cornwall
User avatar
simonineaston
Posts: 7993
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by simonineaston »

My chain keeps coming off the lower jockey wheel and running through the cage beside it rather than on it.
Picture/s please, op
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
mattsccm
Posts: 5095
Joined: 28 Nov 2009, 9:44pm

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by mattsccm »

I have had this. A mix of a buggered mech, a stiff link and siezed jockey wheels which was the main thing. Should have checked a few things before riding a bike just dug out of a pile of bales.
User avatar
frank9755
Posts: 885
Joined: 11 Oct 2008, 10:38am
Location: London

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by frank9755 »

You wouldn't think there was space for it to go to the side.
Here is the 'on' picture

Image

But riding just a few yards with a few gear shifts, and it is back running alongside.

Image

It's 11-speed chain and mech (Ultegra)
Last edited by frank9755 on 30 Jul 2021, 4:02pm, edited 2 times in total.
Jdsk
Posts: 24478
Joined: 5 Mar 2019, 5:42pm

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by Jdsk »

Can you get it to do this with the bike on a stand?

Jonathan
cyclop
Posts: 961
Joined: 3 Oct 2013, 7:49am
Location: Dumfriesshire

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by cyclop »

I,m sure the lower jockey is different from the upper in that it has some sideways movement,probably to accomodate more extreme chain angles.Has your LBS put an upper one on by mistake or perhaps your original one was also an upper?
Last edited by cyclop on 30 Jul 2021, 4:29pm, edited 1 time in total.
mig
Posts: 2695
Joined: 19 Oct 2011, 9:39pm

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by mig »

mech looks slightly bent inwards towards the wheel at the bottom to me.
Jdsk
Posts: 24478
Joined: 5 Mar 2019, 5:42pm

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by Jdsk »

cyclop wrote: 30 Jul 2021, 4:28pm I,m sure the lower jockey is different from the upper in that it has some sideways movement,probably to accomodate more extreme chain angles.Has your LBS put an upper one on by mistake or perhaps your original one was also an upper?
That's clever.

Screenshot 2021-07-30 at 16.34.04.png

What model of Ultegra is it?

Jonathan
borisface
Posts: 356
Joined: 19 Feb 2010, 3:48pm

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by borisface »

It might be the photo or my eyes but the derailleur cage looks to be slightly bent inwards toward the wheel? Does the chain alway fall onto the outside of the jockey wheel?
rjb
Posts: 7183
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by rjb »

Its difficult to see but the hanger could be twisted slightly ie toe in. Best to check the alignment of the hanger before you look elsewhere.
this recent thread may help. viewtopic.php?f=5&t=146971&hilit=hanger
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
Eyebrox
Posts: 580
Joined: 5 Aug 2015, 8:56pm
Location: Ayrshire

Re: Chain going beside rather than round lower jockey wheel - why / how fix?

Post by Eyebrox »

The hanger looks bent inwards and the derailleur cage is twisted. Check and straighten the hanger with an alignment tool. Drop the chain to the biggest cog and straighten the cage with a heavy duty shifting spanner, using the wheel as an alignment aid.
Post Reply