My brother has a Brompton M6L with Crystalite 209 motor (Nycewheels conversion) and it is HEAVY at 34.5lb w/o the battery. Add about another 4 lb for the 10Ah battery. I tried another Brompton M6L with Freedom Ebike conversion (Tongxin motor) and the whole thing with the 5Ah battery weighs about 30lbs. The Tongxin motor has much better freewheel (less drag) than the 209 Crystalite motor.