After the disastrous recall of every single one of its first model of derailleur (the SRAM ESP 900), SRAM boldly stuck with it, slightly redesigning the gear and sorting out the manufacturing process - and the SRAM ESP 9.0 was the result.
The design of the 9.0 includes all SRAM’s signature features; the one-to-one actuation, the steeply angled slant parallelogram, the lack of float in the guide pulley and the single sprung pivot design with the top pulley wheel concentric with the sprung pivot (all except one-to-one actuation follow the basic design of the SunTour V GT).
When manufactured using ‘carbon composites’, with sealed bearing pulleys and an aluminium attachment bolt, the result was a very capable gear.
This example is a camouflage version, perfect for fun day out mountain biking with the casts of Duck Dynasty and Swamp People. It weighs in at a chunky 231g, more than 40g heavier than my lightest SRAM ESP 9.0SL - so the 'SL' moniker really did mean something.