Monterey Car Week is where the world's most monied automotive enthusiasts congregate once a year, and as many car enthusiasts share a similar passion for motorcycles, there's always a smattering of elite motorcycles spread across the six auctions.

This year there are 15, maybe 16 motorcycles that are expected to fetch six figures, spearheaded by two Crocker v-twins likely to sell for more than US$500,000 apiece in Monterey.

1936 Crocker Small Tank

Mecum | Estimated price: $700,000 to $800,000

Likely to be the most expensive motorcycle sold in Monterey this year, this 1936 Crocker Small Tank 1000cc V-twin is one of the rarest and most desirable of all American motorcycles. The exact number of Crocker v-twins produced is vague and has been estimated from somewhere between 60 and 200 made between 1936 and 1942, when the war effort saw the company turn its attention to making aircraft parts. Regardless of how many might have been made and subsequently lost to time, a meagre 50 extant Crocker V-twins suggests they won't be coming around very often at auction.

Conceived as performance cruisers, they significantly outperformed the Harley-Davidsons and Indians of the day, and hence bikes were often cannibalized for their powerful, reliable 1000cc engines, most notably for speedway cars.

1937 Crocker Small Tank

Mecum | Estimated price: $600,000 to $700,000

Similar to the bike above, another one of Albert Crocker's rare masterpieces. One piece of Crocker history that often goes unmentioned is that Crocker's foreman and the designer of many of the bikes components, Paul Bigsby, found subsequent fame as the inventor of the Bigsby vibrato tailpiece for guitars, a "must have" for any serious guitar player, and a standard fitting for almost all of the guitars of the stars. A "Bigsby" is fitted to many of the 100 most valuable guitars ever to have sold at auction.

1938 Brough Superior SS100

Bonhams | Estimated price: $300,000 to $400,000

This beautifully restored 1938 Brough Superior SS100 was delivered new to C R Hussey in 1938, though records also show that it is the bike piloted by George Brough in the 1939 London to Edinburgh endurance run, which was written up in the June 1939 issue of Motor Cycling magazine (U.K.).

The record price for a Brough Superior is £416,250 (US$549,349) set by a 1930 Brough Superior SS100 on March 2, 2019 by H&H Auctions at the National Motorcycle Museum in the United Kingdom.

Other top prices fetched by Brough Superiors in the past include $492,973 (sold for £315,100) for a 1929 Brough Superior SS100 "Alpine Grand Sports" sold by Bonhams on November 30, 2014, a 1932 Brough Superior 800cc Model BS4 Project that sold for £ 331,900 (US$478,059) and was part of the famous "Broughs of Bodmin Moor" barnfind, and a 1922 Brough Superior SS80 sold for £291,200 (US$463,847) by H&H Auctions in October, 2012.

Steve McQueen's 1936 Indian Chief

Gooding & Co | Estimated price: $250,000 to $350,000

This 1936 Indian Chief was part of the famous 1984 McQueen Estate Auction in Las Vegas and comes with all the authenticating documentation, making it a genuine ex-McQueen example of the actor's favorite marque. We've written extensively on McQueen's auction block magic, and it will be interesting to see if he can add yet another marque to his list of most valuable examples. Ex-McQueen bikes already include the two most expensive Husqvarnas ever sold, the most expensive motocross bike ever sold, the most expensive dirt bike ever sold, and the three most expensive two-stroke motorcycles ever sold.

The most expensive Indian ever sold at auction is currently the 1928 Indian Altoona Hillclimber which fetched $247,500 at the E.J.Cole Collection sale in March, 2015. This bike might well break that record too.

1914 Flying Merkel 1000cc V-Twin

Mecum | Estimated price: $175,000 to $225,000

This 105-year-old 1000 cc V-Twin bears one of the most famous names in motorcycle history, and comes with a complete history dating back to its original registration in Sweden. It is an older restoration, having been part of the famous MC Collection of Sweden.

While it is unlikely to set any marque records (the record price of $423,500 was set by an unrestored 1911 Flying Merkel board track racer at the E.J. Cole sale in 2015), this bike might become the second most valuable Flying Merkel ever sold if it fetches more than the $192,500 fetched in Monterey by a 1914 Flying Merkel in 2015.

1938 Brough Superior SS 80

Mecum | Estimated price: $150,000 to $200,000

The SS80, as the name implies, was guaranteed to do 80 mph (129 km/h) when it was new, and generally doesn't fetch as much as an SS100, with the exception of the famous "Old Bill" that was sold for £291,200 (US$463,847) by H&H Auctions in October, 2012.

1918 Indian Board Track Racer

Mecum | Estimated price: $170,000 to $190,000

In terms of authenticity, one of the key variables in any auction price, this unrestored 1918 Indian Powerplus Board Tracker ticks all the boxes, complete with its original racing scars. Most importantly, it is an original factory racer, that was originally raced at the Los Angeles Speedway.

2014 Lotus C-01

Mecum | Estimated price: $125,000 to $150,000

Only 100 of these 180-kg (397-lb), 200-hp 1200cc V-twin Lotus C-01 motorcycles were ever made, though they have not fared well at auction. One of them did receive a bid of $190,000 at Monterey in 2015, but it didn't meet the reserve price and was passed in. To our knowledge, there's never previously been one sold at auction.

1912 Indian Twin Board Track Racer

Mecum | Estimated price: $100,000 to $175,000

This 1912 Indian 61 CI Board Track Racer has been superbly restored by Jim Prosper, who is well respected as one of the finest restorers of early Indians and known for his use of nearly all factory parts, giving the machines unparalleled authenticity. This machine has earned an AMCA Junior 1st at the Yankee Chapter meet and an AMCA Senior award for its excellent attention to correct period details. Close inspection reveals the correct Indian-stamped pedal cranks, handgrips, pedals, Bosch magneto and Hedstrom-improved racing carburettor.

1913 Dayton Big Twin

Mecum | Estimated price: $115,000 to $125,000

This 1000cc v-twin 1913 Dayton is a very rare example of the machinery created by the Davis Sewing Machine Company. It is a single-speed machine with a clutch and is capable of a top speed of around 113 km/h (70 mph).

1915 Harley-Davidson 11F

Mecum | Estimated price: $100,000 to $120,000

The 1915 Harley-Davidson 11F is arguably the company's most important model. A complete redesign enabled power to increase by 37 percent, and the gearbox was so sturdy that it remained in production for another two decades. This example has just undergone a museum-quality restoration that was completed in May 2019, overseen by AMCA Judge and noted restorer Dave Fusiak.

1978 Ducati NCR Race Replica

Mecum | Estimated price: $90,000 to $120,000

Although it is a replica, this Ducati racer is still very special, being a one-off creation built with the assistance of the legendary NCR workshop by Ducati specialist Torbjörn Lindgren. Assistance in building the bike and sourcing the parts was also given by Steve Wynne at Sports Motorcycles in England, sponsors of Mike Hailwood's epic Isle of Man TT win in 1978, the victory this bike commemorates. The record price for a genuine Ducati 900 NCR is $175,500, achieved by Bonhams in January, 2014.

1912 Sears Dreadnaught V-Twin

Gooding & Co | Estimated price: $80,000 to $100,000

The Sears Dreadnaught 1,157 cc v-twin was sold by Sears Department Stores via mail order from 1912–1916, and very few are known to survive. This restored model comes with a stellar provenance, having been purchased at the Harrah's Automobile Collection auction in September 1985 by Formula 1 World Champion Phil Hill. It is being offered for the first time in 35 years.

1914 Harley-Davidson 10E

Mecum | Estimated price: $75,000 to $100,000

Restored to original condition with original parts, this bike comes with a racing history, a racing trophy from its past, and leather racing helmet

1914 Harley-Davidson 11K

Mecum | Estimated price: $65,000 to $100,000

This 1914 Harley-Davidson 11K is an ultra-rare example of Harley-Davidson's first factory racer, with only four or five examples known. It won the 2017 Greenwich Concours d'Elegance for Most Outstanding Motorcycle, and has Wheels Through Time Museum certification.

2012 Orange County Choppers 100-mpg
Turbo Bio Diesel Triple

Mecum | Estimated price: $50,000 to $75,000

There is no chance you'll ever come across another machine like this one. It's a street-legal, three-cylinder, turbo diesel motorcycle built by Paul Teutel Sr. and his team at Orange County Choppers. It runs on bio-diesel fuel, gets 100 mpg (2.4 l/100km), and was featured on the famous TV show American Chopper.

View gallery - 18 images