Three main factors determine any vehicle's value, according to Karl Brauer, editor-in-chief of Total Car Score.
Those factors are rarity (how many initially produced compared to how many are left today), innovation (was this vehicle a technological breakthrough when it debuted), and whether it has a successful race history (which always increases value).
Brauer compiled this list of what he says are the 10 most-valuable motorcycle models. The rundown includes scarce antique models and in one case, a motorcycle that appeared in a famous photo. Read on to see those bikes.
1. 1948 Vincent Black Lightning Prototype
The 1948 prototype for the Vincent Black Lightning is also known as Rollie Free's "Bathing Suit Bike." Clad only in a helmet, swim trunks and tennis shoes to improve aerodynamics while lying face down across the top of the motorcycle, Free set the land speed record of 150.313 mph. His feat was documented in a photo that became an iconic image in motorcycling. In 2011, this one-of-a-kind chopper set another record when it became the first motorcycle to sell for $1 million.
2. 1915 Cyclone
This nearly century-old cycle was the most powerful of its time, said Brauer. Its 1,000 cc V-twin engine with 50 horsepower was capable of over 120 mph, which Brauer said was "an incredible speed at that time for what was essentially a bicycle with an engine." About 300 were made but only 15 are left, and they can fetch over $500,000. One Cyclone fetched $480,000 in a 2008 auction by Mid America Auctions.
3. 1939 BMW Type 255 Kompressor
BMW was one of the first manufacturers to use supercharger technology. "BMW combined a supercharged, dual overhead camshaft engine with a four-speed transmission to create an advanced and powerful series of racing motorcycles," Brauer said. A BMW Type 255 Kompressor recently went for $480,000 in a January 2013 Bonham's auction.
4. 1929 Brough Superior SS100
The Brough was guaranteed to hit 100 mph, and in the 1920s and '30s, it was considered the Rolls-Royce of motorcycles, according to Brauer. "Advanced suspension and frame design made the bikes extremely capable by the standards of the era," he said. Prices can go anywhere from $100,000 to $400,000. One sold for approximately $148,000 at a Bonham's auction in October 2010.
5. 1949 Vincent Black Lightning Supercharged
Many motorcyles on this list have set speed records, and that's what the British dealer of this Vincent Black Lightning was after when he rigged it with a supercharger. It never did break any speed records, but many years later in 2008 it did break a different kind of British record, when it sold in a Bonhams auction for $383,400.
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