I have to agree with fietsbob and chagzuki. I had a CK installed a few years ago and never think about it go with because it works perfectly all the time. I cannot say it works any better than a perfectly adjusted, well lubed ball bearing headset, but they don't stay that way for me for long. Sealed bottom brackets, headsets and pedals are 3 things I really like. If bromptons could go with a belt my only maintenance would be tires, cable grease and brake pads.