Gears slipping mid-range

[CogitoErgoSum]

Hi. Before I go bug the LBS...

 

Does anyone have insight into why gears would be slipping in the middle-range of the cassette?

 

Top and bottom is fine

[Bateleur1]

Hi. Before I go bug the LBS...

 

Does anyone have insight into why gears would be slipping in the middle-range of the cassette?

 

Top and bottom is fine

 

First answer comming to mind is wear on the casette and chain.  Most propable cause that it only effects the middle order and not the top and bottom order is that the middel wears out more as it is used more than the other gears.  Quite possible that the situation got worse when putting on a new chain.  If that is the case, replace the casette asap before damaging your new chain.

[Firozfx]

Wear

[Furbz]

you can also get your derailleur hanger straightened

a skew derailleur can cause havoc

[Jacoo]

Wear. Most probably gonna have to replace cassette and chain. Invest in a chain gauge, and start checking your chain wear every few weeks. If you replace your chain when you should, then you should be able to go through about 3 chains per cassette. And take care of your chain, and replace it at somewhere between the 0.5 and 0.75 mark, that way it doesn't wear the cassette.

[Noshow]

Sure it's slipping (wear) not ghost-shifting (indexing/alignment)?

[Goodbadugly]

Wear will not be my first thought. That usually shows in the smaller rings. 

I would go for a bent hanger. Or cables being in bad shape

[solty]

I'm with Noshow, check the indexing first. Couple twiddles of the barrel adjuster should prove or eliminate that as poss problem.

[Sepia]

Wear will not be my first thought. That usually shows in the smaller rings. 

I would go for a bent hanger. Or cables being in bad shape

This. 

[Bonus]

"Wear" is the obvious answer but my chain used to slip in 7th cog and when I changed the chain, cassette and chain rings (which all needed changing anyway) the slipping continued. 

 

Check your rear mech for straightness etc.

[V18]

Wear. Had a rough day up ouberg pass when I'd decided to put a new chain on the day before and not checking. Was slipping in all the gears. Including granny. Currently guilty of not checking my chain again. Going to kill this casette and chain together now.

[Red Bird]

Bent hanger. Had the same issue and LBS sorted it in 5min.

[porqui]

When last did you renew the cables inner and outer.

You may be surprised.

[CogitoErgoSum]

Bent hanger. Had the same issue and LBS sorted it in 5min.

The hanger seems fine. If bent, wouldn't the top range or bottom range slip?

[CogitoErgoSum]

When last did you renew the cables inner and outer.

You may be surprised.

I think this could be the reason. The cassette and chain isn't THAT old.