The 2012 Shimano Dura-Ace (9070) was the first Di2 derailleur that I actually wanted - but it was hysterically expensive. The 2013 Shimano Ultegra (6870) was almost as good (and I mean 99% as good) and was half the price. I couldn't afford it - but at least its price did not induce hysteria. It was 11-speed, it was precise, it was reliable, there were a load of options for the controls if you like aero bikes etc. etc. etc.. And although it was heavy, it was not sooooooo heavy.

Just like the Shimano Dura-Ace (9070), the Shimano Ultegra (6870) was not a pretty thing. It's lumpy and all the levers underneath are just not tidy. But, unlike Shimano Dura-Ace (9070), the Shimano Ultegra (6870) was a significant aesthetic improvement on its predecessor the fat-assed Shimano Ultegra (6770).

This example is a medium cage Shimano Ultegra (6870 GS).

• Derailleur brands: Shimano
• Categories: Shimano - the Ultegra story
• Themes: Electric Avenue
• Country: Japan
• Date of introduction: 2013 for the 2014 model year
• Date of this example: 2017 (two letter date code PF)
• Model no.: 6870 GS
• Weight: 268g
• Maximum cog: 32 teeth
• Total capacity: 37 teeth
• Pulley centre to centre: 86mm
• Index compatibility: 11 speed
• Chain width: 3/32”
• Logic: top normal
• B pivot: sprung
• P pivot: sprung
• Materials: largely aluminium with steel inner parallelogram linkage and a carbon p-knuckle