105 Rear Mech Oddity

Help please guys and girls.
I swapped my 9 speed 105 shifters and cassette from my old road bike to my Tricross Sport (as one of the Sora Shifters was knackered). Before that the Tricross was running an 8 speed cassette and chain on a compact drivetrain. Out of laziness I left the old chain on the Tricross and as expected the gear changes were terrible, so I chucked on the chain from the road bike. I'm presuming this is a 9-speed chain but since it was put on recently by a LBS that I no longer have any confidence in it could be anything. Shifting was perfect and I happily tucked the bike away in the garage while I played with my new bike.
Looked at the Tricross later and realised that in high gears the bike looks fine but in low gear the rear derailleur isn't hanging as expected but is pulled almost horizontal towards the front of the bike. Have I done something wrong, could this be a cage length issue (road bike was double, Tricross is compact), chain length problem? As I say, shifting is perfect but obviously something isn't right.
Thanks!
I swapped my 9 speed 105 shifters and cassette from my old road bike to my Tricross Sport (as one of the Sora Shifters was knackered). Before that the Tricross was running an 8 speed cassette and chain on a compact drivetrain. Out of laziness I left the old chain on the Tricross and as expected the gear changes were terrible, so I chucked on the chain from the road bike. I'm presuming this is a 9-speed chain but since it was put on recently by a LBS that I no longer have any confidence in it could be anything. Shifting was perfect and I happily tucked the bike away in the garage while I played with my new bike.
Looked at the Tricross later and realised that in high gears the bike looks fine but in low gear the rear derailleur isn't hanging as expected but is pulled almost horizontal towards the front of the bike. Have I done something wrong, could this be a cage length issue (road bike was double, Tricross is compact), chain length problem? As I say, shifting is perfect but obviously something isn't right.
Thanks!
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Ribble Sportive Racing: FCN 2
Tricross Sport: FCN 4
Cannondale R600: FCN 3
Scrapheap Rescued SS, in bits: FCN 9
Helmet wearer
===============================
Ribble Sportive Racing: FCN 2
Tricross Sport: FCN 4
Cannondale R600: FCN 3
Scrapheap Rescued SS, in bits: FCN 9
Helmet wearer
===============================
0
Posts
okay:
Too short:
Ribble Sportive Racing: FCN 2
Tricross Sport: FCN 4
Cannondale R600: FCN 3
Scrapheap Rescued SS, in bits: FCN 9
Helmet wearer
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I suspect it was too long on your road bike and is just right on the tricross, hence the mech points further forward than you are used to. Remember that chain length will be influenced by the length of the chainstay, which is likely to be longer on the Tricross, as well as the gears used. The change from double to compact should mean that the chain is too long, but the chainstay length may have counteracted that (and some).
Do the check I suggested.
Ribble Sportive Racing: FCN 2
Tricross Sport: FCN 4
Cannondale R600: FCN 3
Scrapheap Rescued SS, in bits: FCN 9
Helmet wearer
===============================