Take it easy, rider. Motorcycles don’t command eye-boggling prices like other alternative investments or collectibles—such as classic cars—but a rare model can reach into the six-figures.

Experts say that bikes over 25 years old make a solid investment since they appeal to Baby Boomers who seek them out to relive their youth.

Click ahead to take a look at motorcycles that have retained their value.

Posted Oct. 15, 2010

Considered one of the classic American motorcycle brands, a bike made by Indian, especial from the 1920s, can fetch anywhere from $25,000 to $40,000. One from 1953 sold at auction by Bonhams auction house for $60,000.

Rare models of these hand-made British motorcycles can fetch a fine price. In the mid 1980s, motorcycle broker Somer Hooker bought one for $7,000 and sold it a year later for $27,000.

Bikes from this British brand can be worth about $7,000-$8,000, according to auctioneer Jerry Wood.

Bikes made from the British company can be worth over $80,000. In 2008, a Brough Superior SS100 sold for £166,500 ($261,516), the most ever for a British motorcycle at auction.

Only about 20 of these bikes are thought to still be around. Built between 1916 and 1923, one could be valued at close to a million dollars. One of the racers is housed at the Harley Davidson Museum in Milwaukee.

Baby Boomer nostalgia is what drives the market for bikes from the mid 1970s. A 1976 Honda CR125 can sell for $2,500 to $3,500.

This model sold at auction by Bonhams for $117,000 in 2008—a world record for a Ducati, and much higher than the $60,000-$80,000 estimate.

Auctioneer Jerry Wood says that examples of the harder-to-find Hurricane model are worth about $15,000 - $20,000.

The nickname Knucklehead refers to the round engine cover that looks like two hand knuckles. Knuckelheads made from the mid-1930s to 1940s range in value from $10,000 to $100,000.

Only 400 of the Italian bike were made—200 hundred each in red and yellow—and they are worth about $3,500. (1993 Ducati pictured.)