Originally Posted by joseff

@mroli: thanks for the comment. The drop bar thing started because the flat bar hurt my wrists on longer rides. After losing the kickstand, rack and fenders, the bike went down from 12+kg to a more manageable 11.3kg. I wanted to lose more weight though, and having owned a singlespeed folder before the idea appealed a lot. So off came the original transmission, and on came shimano BMX 14t cog. A DIY chain tensioner rounds the conversion. The bike now stands at 10kg with butchered seatpost from a Speed P8 and a lightweight(ish) Velo saddle.

Even with super-duper weight-weenie special components and brakeless fixed gear, I don't think you'll get near 7kg with a Mu. The Mu XXV is 7.6kg (quoted) without pedals, and the only (sensible) way to go lighter from there would be carbon bar and post, painful saddle, and fixed gear.