take the guards off, use a 3 external on a 2 speed hub, loose the bb, steel headset, use ti forks/triangle, ti post with no pentaclip, light removable pedals, kojak / One tyres, super light front wheel, take off the plastic bash etc etc etc
Top tip. Might lose the guards for the summer.I've already gone light weight on wheels, pedal, saddle. Can a normal brompton seat post lose the pentaclip and is the bb not required?
take the guards off, use a 3 external on a 2 speed hub, loose the bb, steel headset, use ti forks/triangle, ti post with no pentaclip, light removable pedals, kojak / One tyres, super light front wheel, take off the plastic bash etc etc etc