Worked on a really lovely S-Works Venge this morning, belonging to my friend.
It had two problems.
1) The rear wheel was canted over to the right at the top.
2) It was not selecting 11 speeds, the rear derailleur range only covered 2 to 11 or 1 to 10.
Cured "1" by turning the right hand cone spring around on the QR skewer. I had often wondered what the effect of fitting them the wrong way round would be! Something learnt today then!
Cured "2" by fitting new jockey wheels. The bearings had worn out in both. The new ones were an upgrade and have ceramic bearings. This was my first encounter with ceramic bearing components. Not knowing the protocol for lubricating ceramic bearings, I got the owner to google it, while I did the work. Ceramic bearings need no lubrication.
Something else learnt!