AM GT Duomatic

The original AM GT model – Moulton’s first stainless-steel bicycle – was launched at the Royal Society of Arts in June 1992.  Motivated by a desire to further improve his bicycle, and to reduce reliance on a single source of frame tubing, the AM GT was built using aerospace hydraulic tubes.  The AM GT had several refinements over other models (such as the Jubilee), including a revised centre joint and rear pivot, stiffer front forks, a softer rear spring, and a titanium seat pillar.  AM GTs were typically built in a 2 x 8 derailleur specification with drop handlebars, although a very limited number were built with flat handlebars or the upturned ‘Loveday’ handlebars.

This AM GT is possibly unique in that it has been built with a Sachs Duomatic two-speed rear hub – as used on the AM2.  We are not aware of another being built in this specification.  The frame and front fork are the same as a derailleur specification AM GT (and the frame has the plate for mounting down tube shifters), whilst the rear fork is specifically designed and built for hub gearing – AM2 type dropouts (modified for 3/8” seat stays) and the chainstays are cranked inwards to bring the hub width down to 115mm.  There are cable stops brazed on to the rear fork so it may be possible to fit a different type of hub gear if desired, provided it is suitably narrow.  However, we consider that the Sachs Duomatic – as used by Colin Martin to cycle to Australia in 1970 – is the perfect fit for this unique bicycle.  Duomatic hubs now command high prices in their own right, as do Moulton AM2s, which are rare and hard to find. 
  

The wheels are, of course, 17”.  The Wolber tyres appear to be in good condition and there is no sign of any rim wear, suggesting limited use.  Other components include a Shimano Ultegra Octalink crankset, Shimano 105 SC front brake, Shimano 600 headset, and a Hope titanium front hub.  The Moulton finishing kit comprises a quill-type wishbone stem, a custom (Moulton) stainless-steel straight handlebar, and a Reynolds titanium seat pillar with Suntour two-bolt adjustable saddle top.

An original AM GT day carrier is fitted, along with black mudguards.  Topping all of this is a leather Lepper Voyager saddle.  These leather saddles were designed by Alex Moulton, and used a saddle underframe manufactured in Reynolds 531 steel to reduce weight – and this weight reduction was very significant as a Voyager tips the scales at only 300 grammes, approximately half the weight of a Brooks B17.  Of course, Brooks introduced titanium-railed saddles but even they weigh 75g more than a Voyager.  Perhaps unsurprisingly, early Voyagers were quite fragile and rails and noses would break, so an intact Voyager like this one is now very rare indeed, and an unusual part of Moulton history – the perfect complement to this unique bicycle.

Taken as a whole, this is a highly unusual and potentially unique example of the AM GT. The combination of Duomatic transmission, low apparent use, and a number of rare original components gives it considerable historical interest. It represents an exceptional opportunity to acquire a very distinctive Moulton.