History could be made in Staffordshire on Sunday 16 October, with Bonhams auctioning a Brough Superior SS100 motorcycle tipped by some to become the world’s most expensive motorcycle.

The official estimate is £240,000 – 280,000. However, whispers are growing that suggest ‘Moby Dick’ will command in excess of £300,000, taking the world record with it in the process. The previous highest price paid for a motorcycle at auction – set by, yes you guessed it, another SS100 - was £286,000 last year at the H&H sale in Somerset, although it's rumoured that the first Brough factory prototype changed hands behind closed doors for £500,000.

Nevertheless, the Brough sold in 2010 surpassed its guide price by £86,000, and obliterated the previous record set in 2008 by £120,000. And no, there aren't any prizes for guessing what type of motorcycle set that one...

It’s unsurprising, then, that Broughs are referred to as the ‘Rolls-Royce’ of motorcycles. The consignment in question is a 1928 model which was dubbed ‘Moby Dick’ by Motor Cycling magazine journalist Dennis May, after he achieved 106mph on it in 1931, and quite probably scaring himself witless in the process. It’s worth remembering that in those days, pushing a four-wheeled vehicle past three figures would have been unnerving enough, let alone a two-wheeled one.

For most people, that is, anyway. But it wasn’t enough for Moby’s first owner, who commissioned oversized cyclinders – from Brough’s engine supplier J. A. Prestwich – as well as an increased compression ratio, higher-lift cams, lightened valves and twin Amal carburettors, adding an additional 13 horsepower. May rode the now-65 horsepower bike again in 1932 and reached 115mph.

Moby was sold in 1936 to the current owner’s father and it changed hands several more times before ending up in its present tenure. During this period, the bike was modified further (allowing it to reach 126mph over a measured mile on the A30) and won a 1937 BMCRC handicap race at Brooklands, lapping the second-placed bike despite starting ‘from scratch’. It was also responsible for 23 of the second owner’s 32 speeding tickets collected over his lifetime.

Accompanying Moby Dick is an old-style logbook (issued in 1945), a 100-page document illustrating the history of this particular SS100, and various spare parts. These include the now worn-out Amal carburettors, and a larger fuel tank which was retro-fitted but since removed in favour of an original Brough unit from 1928.

The Bonhams 'Autumn Stafford' sale will take place at the Classic Motorcycle Mechanics Show on 16 Oct 2011. For more information visit the Bonhams website.

Text: Joe Breeze
Photos: Bonhams