Confusion on sram drive train

[cjabbo]

I've recently fitted a sram 950 9 spd cassette a new sram 9 speed chain and and sram x5 rear shifter and a sram x7 rear derailier... I have slipping on the cassette either on the second from the top 2 sprockets or the lower 2 I've taken my giant reign 2 2007 into the shop and they can't understand the issue either any advice would be most helpful as it's doing my head in ?? Help I'm wondering if the chain is a little short? the shop says not or if there is a thinner chain to stop it riding over

 

[Drago]

Is it a new cassette and chain? Is the tension set properly on the mech? What chainring/chainset you running up front?

 

[rusty bearing]

Have you routed the cable correctly under the clamp bolt at the rear mech? You can never get the indexing right if you haven't which sounds like your problem

 

[cjabbo]

I have got the cable in the correct position but I am going to check the shifting by loosening the cable and shifting see how that feels if I get the full 9 and I'm running a racetech 44 on the front

 

[fossyant]

You aren't cross chaining it - i.e. using the smallest sprockets when on a small chainring, and large/large ?

 

[Milkfloat]

Gear hanger straight?