I used to commute to work on one, winding up with about 20 miles round trip. I'd done the same routes for 20 years on a fixie, a SS and a geared mtn bike, with not much difference in time or effort. 2 differences were I could keep the B in the office and it carried cargo more efficiently than the others as the weight in the front bag, carried by the frame , improved the ride. When there was snow and ice I took another bike, though. Now I'm retired I ride 20 miles with no problem on the Brompton, although it's not broken up into going and returning. I have a bunch of bikes of different types but it's my favorite. When I go to Denver, Colorado or Albuquerque, New Mexico, I take it with me to enjoy the fine trails they have there, without having to use a bike rack or impact much on how much luggage will fit in the car.