I never used the JTek but did the cable wrap trick to use my Ergo 10's with a shimano 9s cluster. When the derailleur was worn - I went with the DaVinci modified SRAM X9 rear derailleur which is made to work with Ergo 10's and 9s rear cluster. Worked fine until I decided to go full Campy 10s. I've got the DaVinci X9 for sale - email me if you are interested.