Originally Posted by 50PlusCycling

I had nothing but headaches when trying to adapt a front derailleur to my Birdy. To keep things simple, I mounted an XTR 9000 Di2 rear cassette and derailleur with an 11~40 range. I run 20" wheels on my bike, so the ground clearance is less of an issue. The gear range is sufficient for the hills here in Tokyo.