Originally Posted by
mattscq
I have a standard 2s Brompton from 2018 (I think?) but the gearing should be 54T x 12/16. It's been fine but I think I'd like to make it a little speedier. Generally what are the pro/cons of switching out the chainring vs replacing both cogs?.
You could turn that 2s into a 6s with a BSR/BWR three-speed gear hub.
Hub Gear Calculator