Retroshift was a based in Portland, Oregon, USA, and specialised in equipment for the pain-and-mud-fest that goes by the name of cyclocross.

It is possible that the company started out in late 2011, and that the key person was Adam Clement. After various of its products caught on, it rebranded itself as Gevenalle in 2014.

I believe that Retroshift introduced its first derailleur, the Retroshift BURD CX, in 2013. This was a microSHIFT model adapted with a stronger chain tensioning spring and was offered with a choice of Shimano Ultegra or FSA Ceramic pulley wheels. Both of these pulley wheel options were judged superior to run-of-the-mill pulley wheels when it came to grinding through mud. BURD stands for 'Blatantly Upgraded Rebranded Derailleur'.

In 2014 this derailleur was rebranded as the Gevenalle BURD CX 10-speed.