that's a good question. i'll have to ask our Brompton rep. We sell these at my shop and I can say that I would put these on my Brompton if I bought one. We sell other upgrades as well that are functionally similar but they're way more expensive. Fancy looking stuff with titanium clamps and all that, but I'm not in the camp of shelling out to take a few grams of weight off any bike except my carbon racer.