The MDev 90 is a design concept introduced by Dr Alex Moulton on his 90th birthday in 2010.
The bicycle is visually similar to the New Series, but using different materials and radically different construction techniques.
The head and seat tube are made from alumunium, and are connected to the central kingpin by tensioned metal wires, in a similar fashion to spokes in a wheel. The metal tension wires are contained within carbon fibre tubes, and the tension in the wires places the tubes in compression and thus ensures the stiffness of the overall frame.
This method of construction contrasts significantly with the traditional approach of brazing steel tubes. Brazing the large number of frame joints on a typical Moulton spaceframe is time consuming and therefore expensive, and the skills required are in short supply, leading to a very expensive with a long waiting list. The MDev concept would allow a frame to be assembled much more quickly and with less specialist skill required. It has even been suggested that the frame could be supplied to a select dealer in a flat pack box, and assembled by a mechanic, perhaps in the presence of the customer.
The front and rear suspension is similar to the New Series / Pylon models, however the front Flexitor units are narrower than on the existing models, something Dr Moulton describes as "slim-line".
Little has been heard about the MDev since the design was initially revealed in April 2010. At that time, Dr Moulton stated that he was in the process of negotiations for the licensing of the Mdev 90. As it was developed by Dr Alex Moulton and Moulton Developments, as distinct from the Moulton Bicycle Company, it is not guaranteed that the bike would be manufactured by the latter.