An auction in Duxford in October will see the world renowned Brough Superior 'Old Bill' motorcycle go under the hammer. Auction organiser H&H say it's "arguably the most important motorcycle ever to come to market".

Expected to fetch upwards of £250,000, the bike has featured in every book ever written about Brough motorcycles.

George Beale of H&H said: "If I could bring any motorcycle in the world to auction, it would probably be this one – the combination of significance and provenance is simply unrivalled in my view."

'Spit & Polish', as it was originally called, was built in 1922 for eponymous company founder George Brough, and he used it to get his first win at Brooklands, where it became the first side valve bike to lap the track at over 100mph. It had a 1,000cc V-twin engine.

Unfortunately, the bike put Brough in hospital on the same day as it broke the Brooklands record, when the front tyre burst.

After that, Brough re-built the bike, changing the forks and swapping out the V-twin engine for a prototype JAP unit. He renamed it Old Bill, after a cartoon character, and went on to win more than 50 races on it during 1922 and 1923.

However, the bike eventually put Brough in hospital again, when he fell of just prior to the finish line of a race at Clipstone, Nottinghamshire.

After that, Old Bill was retired as a racer, converted to a road bike and sold.

Its next accident was especially unfortunate...a cast iron bath fell through a ceiling onto it while it was in storage during World War II.

It was bought by Brough enthusiast Titch Allen in the late '50s, who with the help of George Brough restored it to its original specification. Allen kept it for three decades before passing it to his son, Roger.

Sadly, Roger Allen was killed in a motorcycle accident during a 1992 Isle of Man TT race, and, after his entire collection of bikes was passed to his wife, Old Bill was put on display at the Nottingham Industrial Museum. It's been there ever since.

It will be displayed at the International Classic Motorcycle Show in Stafford between now and the sale.

Auction organiser H&H has estimated it at £270,000, based on the fact that a Brough Superior SS100 currently holds the world record for a motorcycle auction sale, at £280,000. However, Old Bill could feasibly fetch far in excess of that.

George Beale said: "Clearly, the value has been difficult to estimate but, based on our success with the SS100 in 2010, there is no telling what it could make on the day.

"It is an absolute privilege to be handling the sale of such an automotive icon and we very much look forward to being able to show it to the world's serious collectors from the Stafford show onwards."