Oh i will have to spend some money but £90 for a set of brake calipers seems like a bit of a killer if i can get away with only replacing levers n pads which i suppose needs to be done either way... A double crankset seems relatively inexpensive as i have access to some free double cranksets from old bikes right now so im just looking for advice from others who have done this mod and what size bottom bracket they used and anyone who has tried swapping hub internals should need be as the shed this brompton was pulled out of got flooded once im told... next year ill be far from any western country (and never returning to one if i can help it) and back to using sign and body language... Or possibly be road kill by then ive got 8 weeks more in australia so im trying to do what i can now...