Barn Job, the Mutant Drag Bike

Back in the 60s and for 5 years, “Barn Job” was the Number 1 Drag Bike in the world, simply because it was the first drag bike to exceed the speed of 130, 140, 150 and even 160 mph in drag race. However its most significant milestone was certainly to be able to fall first the 10 seconds wall in the quarter mile when the displacement was increased to 85 ci (9.82s at 151.51mph). One man was behind all these achievements: Clem Johnson.

Clem developed and built his Drag Bike from a 1949 Vincent Rapide that he bought in 1954, after being released from his military duty. During the bike racing career that spanned 33 years, Clem Johnson assisted by his partner Ralph Owen made constantly modifications to improve its performance: the weight melted from 403 lbs to 260 lbs, the displacement increased from 61 ci to 96 ci, the injection of Nitro-methane doubled the power from the base line, the stock frame was replaced with a custom aluminum frame, a supercharger was added, Injection replaced the carburetors, in fact the list of modification is far too long to be listed and eventually only the crankcases and timing cover were remaining from the original Vincent works.

Clem raced the bike between 1955 and 1969 and handover Barn Job to his friend racer Jim Leineweber. However he continued to prepare the bike and manage the racing team until the last run was in 1987 with Jim Leineweber. By that time, its quickest run was 8.40 seconds and its fastest 187 mph, quite an achievement for a bike with a narrow rear tire.

Clem passed away on Dec 2, 2013 after making the necessary that Barn Job will find the home it deserved and John Stein, a Dragster enthusiast, was chosen for that purpose. Clem will remain in many’s memory as one of the most talented Drag racers and definitely one of the most brilliant craftsman; his bike, Barn Job is still there to testify his legacy.

Barn Job today as see at Born Free 5. Silverado, CA. The bike is now own by John Stein a Dragster enthusiast who also wrote a book on Dragsters (1) © Mighty Motors — Barn Job today as see at Born Free 5. Silverado, CA. The bike is now own by John Stein a Dragster enthusiast who also wrote the book “Motorcycle Drag Racing: A History” (1)
Picture © Mighty Motors

Clem Johnson with his famous Barn Job, Vincent drag bike in September 1961, Hobart, Indiana. Photo courtesy of Jim Leineweber photo archive. — Clem Johnson with his famous Barn Job, Vincent drag bike in September 1961, Hobart, Indiana. Note that the Brampton front fork is still there but the frame has already been modified as a “hard tail”
Photo courtesy of Jim Leineweber photo archive.

Clem Johnson riding Barn Job off the line at Long Beach California. Note no front brake system on the bike. Photo courtesy of Jim Leineweber photo archive. — Clem Johnson riding Barn Job off the line at Long Beach California. Note that there is no front brake system on the bike.
Photo courtesy of Jim Leineweber photo archive.

Clem Johnson (Black Leather) Photo Gary Richards Collection — Clem Johnson (Black Leather)
Photo Gary Richards Collection

This photo taken in the early 1970’s shows Clem Johnson doing the burn out, between Jim Leineweber (L) and Ralph Owen (R) This photo was once used on bubble-gum trading cards. Photo courtesy of Jim Leineweber photo archive. — This photo taken in the early 1970’s shows Clem Johnson doing the burn out, between Jim Leineweber (L) and Ralph Owen (R) This photo was once used on bubble-gum trading cards.
Photo courtesy of Jim Leineweber photo archive.

Clem Johnson catapulting Barn Job. — Clem Johnson dragging feet and catapulting Barn Job in the quarter mile.

Jim Leineweber a few years later. You can see the evolution of the bike between this picture and the previous one.

In 1987, at Palmdale, California, Barn Job made it’s last pass. Here’s the bike in it’s final form after 3 decades of evolution. Note the supercharger under the drivers seat and no front brake. Photo courtesy of Jim Leineweber photo archive. — In 1987, at Palmdale, California, Barn Job made it’s last pass. Here’s the bike in it’s final form after 3 decades of evolution. Note the supercharger under the drivers seat and no front brake.
Photo courtesy of Jim Leineweber photo archive.

Note the belt driven fuel pump on the left of the primary transmission as well as the aviation flexs that feed injectors.

The upper spine holds the nitro-methane while the vertical one in front of the engine holds the oil. The Nitro double the horse power than the engine is capable to deliver with regular fuel. The frame is all made of aluminum.

Specifications

Displacement: from 998cc (61ci) to 1600cc (96cc)
Flywheel: machined from mild carbon steel
Pistons: machined from forged aluminum billets, cam-turned, and sealing 11 to 1 compression
Heads: 2 front heads with stock exhaust valves (1”11/16) and enlarged intakes valves (1.650)
Carburetion: Dellorto carburetors then Hilborn injectors. Nitro-methane was used from May 1962.
Firing: each cylinder has its own complete ignition system with a common battery.
Gearbox had only 2 gears a 1.73:1 starting drive and a direct drive
Clutch: Johnson-developed clutch with Harley-Davidson components
Frame: Custom made of aluminum 6061 ST aluminum (1/8-inch wall) e use
Front end: 32mm Ceriani road race
Wheels: Borrani aluminum wheels with 2.75×19-inch Avon front tire and a worn-smooth 4.00×18-inch Dunlop Universal at the rear.
Weight: Down from 460 pounds to 260 pounds

(1) http://www.gearheadpublishing.com

Sources

https://www.youtube.com/watch?v=Lh6axnhoTg8

http://gearheadpublishing.com

http://www.baggersmag.com/custom-vincent-motorcycle-barn-job

http://www.nationalmcmuseum.org/featured-bikes/bike-feature-barn-job/

http://www.cycledrag.com/remembering-motorcycle-drag-racer-clem-johnson-creator-of-the-barn-job

3 thoughts

The Brampton girder was replace early on by a welded aluminum alloy replica, which is shown in the above photos. I have never seen a photo of the bike with a standard Brampton.

Back in the early 80s I had a Pro-Stock Suzuki GS-1000. It was always fun watching the Barn Job make 170+ mph smoker runs.

We were at the front of the lanes for the AMA Dragbike! national at Las Vega waiting to make a run and the Barn Job crew was trying to get her started up. They were cranking the bike over when there was a boom and suddenly there were guys running in all directions with their hands over their heads. Half a cylinder head had launched and nobody wanted to be under it when it came back down.

I was fortunate to see Clem’s Vincent run several times at the San Fernando Drag strip way back in the 1960s. It was scary impressive and what a unique sound. I recall the tires were its problem but he was achieving about 150 mph or so. Those sure were wonderful days.

Zniewski says:

August 22, 2015 at 8:08 am

The Brampton girder was replace early on by a welded aluminum alloy replica, which is shown in the above photos. I have never seen a photo of the bike with a standard Brampton.

Eric Marsh says:

December 2, 2016 at 7:45 pm

Back in the early 80s I had a Pro-Stock Suzuki GS-1000. It was always fun watching the Barn Job make 170+ mph smoker runs.

We were at the front of the lanes for the AMA Dragbike! national at Las Vega waiting to make a run and the Barn Job crew was trying to get her started up. They were cranking the bike over when there was a boom and suddenly there were guys running in all directions with their hands over their heads. Half a cylinder head had launched and nobody wanted to be under it when it came back down.

Steve Garcia says:

July 4, 2020 at 3:33 pm

I was fortunate to see Clem’s Vincent run several times at the San Fernando Drag strip way back in the 1960s. It was scary impressive and what a unique sound. I recall the tires were its problem but he was achieving about 150 mph or so. Those sure were wonderful days.