Thank you for the 51 pages of comments to the eR9 and eRX, very useful and interesting information!
During the recent sale I could not resist to get an eR9 without batteries that came in delivered around 300US$.
A great price if the thing works...
For context, I upgraded my mostly indoor Zwift bike with the eR9 since the shifting performance of the GR9 never was great and the thumb shifter is not my cup of tea after trying it for several months. I think the poor shifting performance may have been due to the tight bends of the shifter cable due to the fully integrated handlebar. Going to wireless electric shifting did the trick for me...
I had the GR9 hydraulic levers paired with the Zrace XG calipers, design, weight and color choice were attractive at the time.
My experience with the calipers was less than stelar... the back brake did never work, even after several bleeds. The brake feeling was always soft and not very assuring on steep downhill rides. Installed the heavier L-Twoo calipers and breaking feel and performance is now good.
I am running the eR9 in a 1x11 speed configuration, due to the existing chain and cassette.
I really like the future proof option to upgrade to 1x12 or 2x12 if I want to experiment.
Reading about the water ingress on the deraileur, I decided to use a heat shrink tube to slide over the port of the rear derailleur and then shrieked it to seal the cable in place. I expect this to solve the issue for the time being.
Getting the L-Two app to work is a bit of an issue since the default language is Chinese... after some online search I figured out how to switch the language. Other than that the App is easy to use and the option to fine tune each gear to the tolerances of your cassette is a great feature.
I currently run 46t x 11-36t for my indoor setup, no problem with the B screw to get 36t working even without a deraileur extender.
Time will tell how good the system works and if the batteries discharge quickly. Since use the bike mostly indoors it should at least not cause any issues with water ingress.
BR
Chris