Jumping gears

[Dogzodiac]

Hi,
Recently upgraded to Shimano 105 r7000 about 3 months ago. All fine until a recent ride. Changing gears all seems fine, but shifted down to smallest gears on a long fast stretch of road and then it started skipping or slipping on certain sections of road where it became quite rough. Everytime I hit a section of rough road it would skip or jump then rectify again.
Is it a simple step of slack cables or a slack chain

 

[Illaveago]

Hi,
Recently upgraded to Shimano 105 r7000 about 3 months ago. All fine until a recent ride. Changing gears all seems fine, but shifted down to smallest gears on a long fast stretch of road and then it started skipping or slipping on certain sections of road where it became quite rough. Everytime I hit a section of rough road it would skip or jump then rectify again.
Is it a simple step of slack cables or a slack chain

It sounds a bit like a slack chain by the way you are describing it happening going over rough ground. It sounds as though the rear derailleur is moving due to the vibration and altering the tension on the chain .

 

[Sharky]

Hi, you've used three terms (jumping, skipping & slipping) to describe the symptoms, each of which could mean something different. Can you describe what's happening a bit better? Is it trying to move up/down onto the next sprocket? Is the chain/cassette the same age?
Hope you sort it out.

 

[Dogzodiac]

Hi, it happens very quick. You hit rough ground and then feels as if there is is a quick slip in pedals as if tension has gone. I think I could here chain slipping or changing cogs, but for a fraction of a second. But with the noise of the traffic and my concentration on all that was going on it caught me off guard a little.
Tried to simulate it on a quiet stretch of road, all is fine again. I have only put 500 miles on the bike since the new groupset

 

[Dogzodiac]

Yes everything is the same age

 

[Sharky]

If only occasional and self correcting and

I think I would just live with it for a while. If/when it gets worse, diagnosis will probably become more obvious.
Just make sure you carry the right tools with you for a while - allen keys, chain tool, quick links etc
Good luck​

 

[roadrash]

could the chain be too long, so the derailleur isn't putting enough tension on the chain

 

[Racing roadkill]

Try adjusting the angle of dangle, with the B screw on the RD.

 

[Cycleops]

Worth checking out the suggestions from the two RRs above. As I understand its just the RD you've changed? You could just be due a new chain and cassette.

 

[Ajax Bay]

Confirm you changed your chain and cassette when you regraded to R7000.
When the chain is on large and large what direction (ie o'clock) does the RD cage point?
When the chain is on small and small does the return section of the chain touch anything before the tension jockey wheel?