Bonhams will be offering investors a rare 1954 AJS E95 'Porcupine' motorcycle at its automotive auction in Carmel, California on August 18.
Just one of four E95s ever completed, the Porcupine, so nicknamed because of the spiked cooling fins on its cylinder head, was created as a works racer by British manufacturer AJS.
It is perhaps one of the most legendary motorcycles in history owing to its brief racing success and extreme rarity.
"As far as motorcycles go, the Porcupine is at the very top," says Bonhams CEO Malcolm Barber.
"It is arguably the most beautiful, graceful and innovative racing motorcycle ever built, the perfect blend of technology and art."
Because the number of AJS Porcupines is so scarce, each machine is well known, with all 1954 models being accounted for.
Until recently this particular example, which has a $750,000 estimate, had been on display for more than two decades, occupying pride of place at the National Motorcycle Museum near Birmingham in the UK, its motor having been overhauled by Team Obsolete Equippe.
The last Porcupine to sell at auction was the non-works, privateer-raced Tom Arter E95 Porcupine which made $258,500 at Bonhams in 2000.
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