I have a question on the new 4 speed derailleur. My Brompton is a pre 2017 and doesn't have a barrel adjuster. Do the newer Bromptons have an adjuster on the shifters. I don't see any barrel adjuster on the derailleur but I could be wrong. Just this week I had to adjust the barrel on my Eezz D3 because the shifter was a bit slow. Any guess how to adjust the new derailleur?