Wow look how clean that chain is, and clean fingers as well, is this picture a Photoshop export.
Peter
I'll let you into a secret; It's a brand new chain straight out of the wrapper.
I've been trying to sort the gears out all day but have now given up for the night. I think I may have the wrong rear derailleur, I've already had to buy a new front one because of the chainstay angles.
So, how does this work?
I measured the chain and cut it to right length. I'm using the chainset off my Trek it's Shimano XT M-771-K (26/36/48) and at the rear a new XT M770 Cassette (11-34T) alongside an XT M772 Shadow derailleur. Exactly the same as I ran on my other bike. After fitting the chain and cable I noticed a large amount of slack (chain really hanging low) when on the smallest chainring and smallest sprocket at the rear, not a combination you would use but useful to see how the rear derailleur is taking up the slack, which it obviously wasn't. After checking the chain length a few times and that the RD was fitted correctly I still couldn't work out what the problem was.
Finally, a closer look at Shimano Tech Docs shows that the derailleur I have is a GS rather than the SGS I thought I had (it was fitted by the LBS). I could only identify it from the SGS one by the different cut outs on the back plate. This would explain the slack chain as it's capacity is only 33T against the 45T I need. The question is, how did it work on the other bike? There's only 5mm difference in the chainstay lengths, the other bike being the one with longer chainstays.
I can pick up an SGS M772 tomorrow from the shop but I'm still confused how it worked on one bike but not another.
Anyone got any ideas?
Cheers
Chris