Gregory Dunham from the USA has constructed the worlds largest  rideable motorcycle that is 3.429 m (11 ft 3 in) tall to the top of handlebars, 6.187 m (20 ft 4 in) long and weighs 2.948 tons (6,500 lb). It is powered by a 8.2 litre (502 cu in) V8 engine and has tyres that are 1.88 m (74 in) tall. The top speed is 65 mph with an economy of 6 miles per gallon.

Dunham built the bike over three years at a cost of $300,000. "After a while, I had to do something in life," said Greg Dunham, 49, adding "I've always been an idea guy."

In February 2005 Guinness World Records awarded him a certificate he recieved on June 15 for officially having the world's tallest rideable motorcycle.

 Dunham steers it from a cage below the handlebars as it would be impossible to straddle the bike in a normal riding position. Technically he drives the bike rather than rides the bike.

"People love it," Dunham says. "Fifteen guys came from out of nowhere to see it. One of the guys said, ‘Build me one!’ People love it!"

Dunham started building the motorcycle he calls "Dream Big" in 2002. It wasn't easy.  He twice had problems with the transmission that made him mad enough to want to set the bike on fire. Dunham collected the parts to build the bike from online shops and auto wrecking yards.  He built the bike himself relying on the knowledge gained when he worked in car body and chassis repair at a garage.

Most recently, 'Monster' raised $433 for the American Red Cross for Hurricane Katrina victims during a September 11th fund-raiser on Pacific Avenue.

Below: Dream Big makes a tractor unit look small.

Below: Dream Big, rides over a car, a true Monster bike in every sense.

Below: Dream Big really fits in at a monster truck rally.

1.Powered by a 502 cubic inch V8 with 500 HP/ 600 ft.lbs of torque. Steel heads, ported and polished . Engine blueprinted and balanced. Medium lift roller camshaft, high performance 870 cfm carburetor, H.O. electronic ignition and wires, custom ceramic coated big tube headers attached to 5 inch diameter chrome exhaust, no mufflers!

2. Transmission is automatic with 2 speeds forward and reverse, all heavy duty components including a 2500 rpm stall convertor. Drive shaft driven through one gear box with the final drive using a custom made spooled Dana 60 rear end using all the strongest components to turn the special made rear main axle.

3. Power disc brakes with two 12 inch vented rotors on the front and one 15 inch vented rotor on the rear using two calipers for maximum braking. All brake pads are non asbestos, utilizing the brake material with the best grip.

4. Power steering is provided by a high performance rock crawling steering gear box powered by a heavy duty chrome pump powered by the engine.

5. A separate electric powered hydraulic system powers the rear wheelie bar/ kickstand for its raising and lowering capabilities. The bar is also equipped with solid rubber wheels and hydraulic rams that will push or pull over 10,000 pounds each. The wheelie bar is used in place of the leg support you would ordinarily use on a normal motorcycle and can be raised after the giant bike is moving forward about 20 mph. Not something I do often due to the costly nature of a crash and danger to others.

6. Fuel tank is a polished aluminum fuel cell which has a foam liner and only holds about 3 gallons high octane fuel. Why so small? How much fuel do you want to sit on? Even at 1 mile to the gallon it will cover most events.

 7. Fuel tank pods and fenders are all custom hand laid fiberglass taking weeks of work starting with only a basic design. The fuel tank pods are easily interchangeable and we do have a second set which vinyl advertising can be applied to so a sponsors name can be applied to the bike. We are always looking for sponsors and can adjust the bike according to the sponsors advertising.

8. The seat is metal tubing framed covered with exterior vinyl to last in the elements. The seat has gas assist shocks to help raise and lower the seat slowly. The inside is cut out so 1-3 people can stand there for photo’s or parade use. 

9. Drivers compartment is set up to vaguely meet some monster truck specifications. Using the bike frame to encompass the seated driver, acting as a full roll cage for the driver protection. A full race seat with a 5 way seat belts were added but because of the limited visibility another steering wheel and brake pedal was added so the driver could stand up to drive the bike with 360 degrees of visibility. Of course the upper driving position is only for slow safe driving. The drivers compartment is also fitted with all the necessary gauges, power switches and controls at hand to operate the monster bike.

When I went to pick up the parts I was amazed at how they turned out plus the paint scheme blended with the bike perfectly. It was beautiful! Rick said that even though the Dupont paint was easy to use the overall project took him over a 100 hours to complete! The custom realistic flames were freehand airbrushed using a white and yellow ground. The largest orange color was based with a silver to gold fade so in the proper lighting it has an infinite color effect and is highlighted by the flames and black crystallized marbling effect.

Even the name Dream Big! really stands out in the sea of molten orange candy color top coat. With names like Psycho Silver, Snow Storm, Smooth Yellow, Crystallized Black, Molten Orange Candy, Gold, and topped off with the depth of a great clear coat it had to turn out great!

12. Builder Information. Gregory Dunham from Stockton, Ca. has a motorcycle background starting at age 9 when he rode bikes on a farm he lived on. Due to the large number of equipment on the farm he received a lot of mechanical experience which was eventually used to design and build the giant motorcycle. After school hours and week ends, at about age 11 he work daily at his families body shop even helping to repair damaged frames. The Dunham family has a vast history of metal working dating as far back as the early 1900’s. 
Even at the age of 14, Gregory’s hobby was motorcycles and would spend hours repairing and prepping his bike for the local motorcross races where if he didn’t crash he usually finished on the podium. In high school shop class and welding was taken but other than that no other mechanical related classes were attended so most of his mechanical and engineering ability comes from his many hours of experience accompanied by using a common sense approach. 
Obviously it can work! Before building 'Dream Big' Gregory has worked repairing all types of frames, major collision work, specialty car work, rebuilt totaled cars and trucks as a side line, remodeled his houses, owned his own business, built the worlds tallest ride-able motorcycle and has full support from his wife of 30 yrs.

www.monster-cycles.com is our website and is currently being updated with the latest photo’s, books, movies it is featured in, supporters, events , past events, event comments plus a short video with Dream Big in white trim crushing a truck. Check back often for the latest news and locations or email us. In addition we will be setting up a store on the site with pictures, shirts and Dream Big memorabilia for the collectors of the worlds biggest and the best! Or we could even build you a monster motorcycle ! Chopper plans are also available.

I would personally like to thank Mr Dunham for providing me with photos and information to help build this web page about his record breaking super big bike "Dream Big"  Rock On ! and chill-easy there