I’m trying to upgrade my road bike. Currently Tiagra groupset with over 2500 miles.

I’ve fitted…
– New Ultegra cassette (10sp)
– New Ultegra rear derailleur (M cage)
– New KMC chain (10sp)

Shifting is reasonably okay but the chain is not running smooth through the jockey wheels in certain gears.

Top Jockey wheel – seems to ‘ping’ and jump with every revolution

Lower Jockey wheel – chain is trying to slide off the cog (out – away from the cassette) when I’m in largest chainring front, 6th-10 largest cog on cassette. It gets worse from 6th to 10th and louder as it goes.

I’m no expert but I’ve fitted new groupsets before, not sure what’s going on here.

The higher limit screw – seems to be lined up ok and the shifting works reasonably well

Lower limit screw – lets me get to top sprocket, doesn’t allow it to go further

B tension screw – This is very loose, when in smallest cog front + largest cog rear the jockey wheel is quite close to the cassette

Any ideas?

Check the mech hanger alignment? Then whether the cage is bent… Had this problem before and it confused me too.

Chain that the chain is correctly routed around jockey wheels and it’s not rubbing on that metal tab?

Chain is routed ok – no rubbing, the chain just follows a different ‘line’ than the cage in certain gears

the hanger should be fine – nothing has changed since yesterday with the old derailleur on it

Not sure how to check if the cage is bent. Looks ok. Brand new so shouldn’t be.

I could take some pics..

Not the best pics but here goes:

Chain is in largest front and back – where the problem is most noticeable.

You should never ever be in that gear anyway, no wonder its complaining!
I always leave the top 2 for small chainring only and the same goes for the other end too.

Is your wheel sitting straight?
Is the chainset sitting further out than the old one?

Yeah but this is affecting gears 6-10. And avoiding the top 2 gears is to stop front derailleur rub.

BUT the chainset question is a good one. The cassette had a spacer that went on first before ANY cogs. My old one didn’t. I pondered whether that was necessary but the instructions seemed to show that it did go on first.

just pulled the instructions out the bin…

that spacer is only for 10 speed cassettes on 11 speed hubs (or something like that) – either way – I don’t need it….

I reckon that’s cracked it – will let you know

cheers

Damn.

Removed that spacer but it’s still doing it!

The instructions say the spacer is not needed if using a “special 10 -speed freewheel”. I’m not sure if it’s special, but it is a 10 speed hub (Ambrosio). So now I’m not sure if I need the spacer or not.

Wheel is on correctly. So need new ideas.

Just replaced the derailleur with the old one (which was working fine)…. and the problem remains. So the problem isn’t with the derailleur at least.

I can’t imagine anything could be wrong with a brand new chain, which leaves the cassette.

Edit: Scrub that. Me and my dodgy eyes.

New theory…

Could a worn chain ring + new chain cause problems with the chain at the T jockey wheel? I don’t understand how it could, but piecing things together:

1. The front chain rings have had over 2500 miles;
2. I don’t get the skipping problem with front lower chain ring, only the big cog;
3. The big front chain ring is used much more so likely to be much more worn

4. My old derailleur inherits this “new problem” when I put it back on, and I can’t see anything wrong with the cassette fitting

Here it is…

That chainring looks reasonably worn (although a pic without the chain on it would help a bit more). You definitely need the 10spd spacer btw.

Stiff link in chain?

can the problem with a worn front chain ring + new chain manifest itself elsewhere though – i.e. at the T jockey wheel?

My first thought was worn chainrings. It won’t show on the old cassette/chain, but as soon as you put on new ones it does.

yeah I’m pretty convinced that’s it – though I was expecting that to cause skipping on the worn chain ring itself, I don’t understand why the problem would manifest itself at the T jockey wheel.

Yes it’s absolutely the Chainring….. Had exactly this issue and totally solved by going single ring and replacing worn Chainring. Push the chain into the root of the chain ring and see how much slack there is….. If the link between pins lifts up then time for new ring.

Mech hanger alignment. Start with that first, otherwise you are pissing in the wind.

I really must get a shortcut set up to post that when any gear problem threads pop up on STW. 😉

mech hanger alignment doesn’t make sense here though, bearing in mind it worked fine yesterday, only when I’ve fitted the new cassette, chain and derailleur has it started doing this.

It doesn’t make sense, but it can make a difference. I walked in to my LBS a few weeks ago, owner was having a few problems doing exactly what you’re doing. Tried the mech hanger alignment tool on it, only a little bit out, but it solved the problem.

It could be a dodgy, Friday afternoon, new mech. Seen some shockingly bad ones out of the box in my time. Cage not on straight.

Directional chain on the wrong way?

KMC quick link on the wrong way?

Both?

Put the spacer back in to start with; you do need it.

Check the freehub for any play aswell.

Fixed

Embarrasingly, the problem was the exactly where the problem was arising – the T jockey wheel

I put it on back to front. Although I was convinced I had it on the right way, I’d been pulling the chain the wrong way through it to test – effectively pedalling backwards.

Feel like a right ****. Never mind. Job done.

I think it was God’s way of making me buy a new crankset.

Why did you take the jockey wheel off in the 1st place? Does the chain not have a split link for fitting and removal?

My new chain does, but I initially tried to fit the derailleur to my old cassette and chain. The old chain was a Shimano so no SRAM/KMC powerlink, so taking the jockey wheel off was the easiest way to fit…. had I not put it back on wrong!