My steel conversion was slightly less than 6kg (13 pounds). The light stuff were old Dura Ace road cranks, old Mavic gl tubular low profile rims, carbon bianchi fork and a carbon seatpost. The bike had a front campy monoplanar brake operated by a cane creek tt lever.

The frame (road TT with curved seat tube, replaced dropouts) is 1700g, the wheelset is 2050g with tubbies. The wheelset was about $160 + the cost of tubbies, the frame was $80, the track ends it needed after the crash were $17. Total was $500ish, this is still my favourite bike - it is being rebuilt now.

I could shave another pound, were I not caring too much for comfort: I am using middle weight tufo tubulars (the lightest with an anti-punch belt), a pretty heavy saddle and reasonable hubs: Mack rear, formula front (the lightest fronts use too small bearings for my likeing).