AJS E95 'PORCUPINE' AT QUAIL

Rod Coleman aboard the AJS E95 'Porcupine' in 1954

While Grand Prix circuit motorcycle racing is almost as old as the 20th Century, the World Championship racing series was only introduced in 1949.  From 1924-37, a single race on the Continent determined the 'European Champion', and a points-based racing series was introduced in 1938, a more accurate measure of success over time, although it was still a European Championship.  The first years of the World Championship, in 1949 and 1950, saw several manufacturers win the top prize in their respective capacities, before disappearing forever from the rosters of GP history.  The 1949 World Champions included AJS (500cc - Les Graham), Velocette (350cc - Fred Frith), Moto Guzzi (250cc - Bruno Ruffo), Mondial (125cc - Nello Pagani), and Eric Oliver/Denis Jenkinson (sidecar - Norton).

The E95 with pannier tank removed, the 'wet' sump clearly visible beneath the engine

The following year, AJS was absent from the World Championship list, never to return.  Velocette managed again to claim top spot (Bob Foster aboard) one more time, but that was the end of their dominance in the 350cc class, taken over by Featherbed Norton of young wonderstar Geoff Duke the next two years.  After that, a British motorcycle would never again howl under a World Champion.

The compact lines of the E95 are clear, even if the tank is huge!

The AJS which emerged victorious in that first Championship year was an unusual machine, and the only twin-cylinder racer ever to win the big prize.  The AJS 500cc 'E90' was drawn up during WW2, as a replacement for the very naughty supercharged AJS V4 racer, a tremendously powerful machine with a chassis too light for the weight and torque of the engine.  While extremely fast, its camelish handling meant lighter, better balanced racers eventually won more races.  AJS designer Vic Webb drew up a new twin-cylinder racer, the engine nearly horizontal, with double overhead camshafts driven by a train of gears.  Weight was reduced by extensive use of magnesium castings. Space above the gearbox meant a supercharger was possible, but Webb hedged his bets and made it possible to run the E90 with unaided breathing.  The complicated cylinder heads were reputedly cast in solid silver at first, for its superior heat dissipation qualities, but no one has ever seen such heads, and the story may be apocryphal, or somehow related to the foundry which cast the E90 heads, in Sheffield (known for its silversmiths).

A compelling work of mechanical poetry; the clutch alone is a mesmerizing sculpture.

The press dubbed E90 the 'Porcupine' for its distinctively spiky cylinder head finning, and while the bike was very fast and handled well, carburation was always an issue, as was a propensity for snapping the magneto driveshaft.  Still, a win at the Hutchinson 100 in 1948, plus several GP podium positions, meant AJS were on the right track.  Development continued, and enough issues were sorted by 1949 for Leslie Graham to win two GPs and secure that inaugural World title.

AJS redesigned the machine in 1952 and dubbed it the E95, which had cylinders more upright (and less spiky), and a chain drive to the magneto.  By 1954, a huge pannier fuel tank lowered the center of gravity, but required a fuel pump keep the carbs fed... and the mechanics to stand the bike on its rear wheel before a race, to prime a header tank for the fuel pump!  Jack Williams took over the race team and development of the E95, working out most of the bugs, resulting in a smooth and reliable engine which produced 58hp @ 7800rpm.  One last win at the Swedish GP, plus 2nd at the Ulster GP, were the swansong of the E95, as AMC founder / racing legend Charlie Collier died that year, and direct involvement in Grand Prix racing was wound up for good, although AMC continued to provide their legendary single-cylinder AJS 7R and Matchless G50 racers until 1962, for privateers.

A single AJS E90 survives, as do all four of the E95s built.  They're fascinating and beautiful machines, the technical equal of any racing motorcycle ever made.  The ex-National Motorcycle Museum E95, restored by Rob Ianucci's Team Obsolete,  will be sold by Bonhams at the Quail Motorsports auction on August 18/19, 2011.  If you happen to be in northern California the week of Pebble Beach/Quail/Monterey Historic races, definitely stop by the Bonhams tent for a rare view of this exceptional motorcycle.  (The Bonhams sale page can be viewed here)