Ms Slomo is getting quite keen on riding around town on Boris Bikes but wants something lighter and I've been asked to come up with ideas. She lives in a first floor flat which shares a narrow hall and staircase. I thought that a folder might suit her needs as long as it's got biggish wheels and is quite light......say 20" at least and less than 12kg. She could stash it in her flat without too much difficulty. I thought a Dahon Briza D8 or a Dahon Mariner D8 might suit her but I know very little about either. If anybody has any views on either (or alternatives) I would be grateful to hear them. Budget is £650 absolute tops, preferably £550. I'm sure that there are secondhand bargains to be had, but I would rather not take the risk given my complete ignorance. (The Dutch style one is the Briza) Thank you.