Chain 'sticking' to 2 teeth on rear dérailleur?

[Butty1972]

Last night I popped the bike on my new workstand and was having a look around it (all part of the learning exp for me), and as I ran the pedals forward slowly, I notice that the chain seems to 'stick' on 2 teeth on the upper cog of the rear derailleur.. not a lot, they just seem to hang on to those teeth for a split second longer, and the chain deforms a little as it sticks for a split second... then clicks back..
I gave it a quick clean, but still occurring.. almost as if the teeth were undercut, but i can;t see that.

It's the world's cheapest groupset, shimano albus or something, so I guess I got what I paid for, but I'm just interested as to what might be causing it, and how i might cure it...? Any advice much appreciated.

The workstand is awesome by the way, £27 from Amazon, brilliant, but now I can see just how dirty the bike is... :-)

 

[Crackle]

Stiff links in the chain?

 

[Butty1972]

don't think so, it seems to happen on every rotation of the cog, not each time round of the chain...

 

[jarlrmai]

have you remove the hangar cage and degunked the jockey wheels?

 

[Butty1972]

No, just a rub-clean, going to see if i can give it a proper scrub tonight, but it looked gunk-free....

 

[ColinJ]

You might need to tweak the B-screw adjustment.

This isn't a brilliant video but it is explained after about 1 min 25 sec ...

 

[ColinJ]

Hmm, I reread your post and it probably isn't the b-screw in your case (though it might be!) but somebody else might find that video useful so I will leave it up.

 

[Erudin]

Try adjusting the limit screws.

After fitting a new chainset I had this happening on when the chain was on the 11t cog the other day, the chain seemed to be lining up perfectly on all the gears.

I fitted a new chain, cleaned jockey wheels and it was still happening. It turned out to be the H limit screw on the rear mech needed turning counter-clockwise a tiny bit.

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

 

[jagman.2003]

Is it just one of the gears that is sticking? i.e. 3rd. Could be fat or bent teeth on that specific gear?

 

[Butty1972]

No, sorry, I'v not been clear enough, and my ignorance re terminology is showing :-)
It's on the top jockey wheel that the chain appears to be 'sticking'... not on the gear cassette itself.
However, rode in this morning, no impact as far as I could tell... i can probably live with it until n+1

 

[Globalti]

Jockey wheels can get worn to the point where they resemble stars. They also seem to have a mysterious ability to attract dried crud and grease.

 

[Butty1972]

Yes, full strip down and clean this weekend perhaps..