1941 Harley-Davidson Knucklehead

Carl used the Knucklehead for many years but began restoring it in the late 1980s. Sometime in 1993, he wrapped up the recommissioning of the machine, and at that point, he occasionally rode the bike, and would proudly display it at local shows. With failing health, however, Carl died at age 89 in 2010. Three years later, his daughter Carolyn Danek was clearing up her dad’s estate and offered the Knucklehead for sale. Enter Tony Hessner of Wauwatosa, Wisconsin.

When Tony learned the Harley-Davidson was for sale, he arranged to see it, liked what he saw, and was happy to pay the cash asking price. For him, the Knucklehead was a desirable machine that joined several others in his collection, including a Honda Nighthawk S and vintage single and twin-cylinder BMWs. “I had a friend with a large collection of bikes,” Tony says of his initial attraction to the Harley-Davidson. “He’s got just about every year Knucklehead that Harley produced, and I rode one of his and quite liked it. He simply said, ‘Get yourself a Knucklehead sometime,’ and at that point it was more a dream than anything else because they weren’t inexpensive nor often available for sale. But this one turned up in 2013, and I jumped at the chance to own it.”

Digging deeper

Tony was happy to get the Knucklehead and appreciates Carl’s connection to the machine. When Tony bought the bike, he was given several pieces of documentation. One of those pieces was an undated story about Carl from the Waukesha Daily Freedom newspaper. In the story, reporter Jack Burke wrote about Carl finally receiving the Legion of Merit — 50 years after he saved the lives of three Army friends in German-held territory in France.

It’s quite the story, and Jack wrote that it was in November 1944 when “Schmidt and four others were on patrol … [and] they crossed into a field of land mines. One soldier was killed instantly, and Schmidt and the rest were wounded after a land mine exploded. The two lead soldiers were stranded inside the field, surrounded by unexploded mines. Schmidt’s lieutenant was hit in both legs and bleeding. Schmidt, who was wounded in the legs and arm, had to act. To keep his lieutenant from bleeding to death, Schmidt used his belt and his lieutenant’s belt as tourniquets. He then ran back toward his unit to find help.”

The story continues, “Schmidt brought back medics to tend to the lieutenant, and then risked his own life to save the other two wounded soldiers. Using his bayonet tip to gently prod for buried mines, Schmidt slowly laid out a safe path to the two men and carried them back to safety.” That wasn’t Carl’s only act of bravery during the war, and he was also awarded the Silver Star and Legion of Merit for gallantry in action. With that background, as Tony rides, shows and talks about the Knucklehead, he is more than happy to carry forward Carl’s stories of bravery.

Tony believes he is the third owner of the Knucklehead, and says, “When Carl won it in the poker game, it was at the time a relatively common, 9-year-old motorcycle — but I wonder if he’d have ever imagined how popular Knuckleheads would become?” He continues, “Carl did use it, enjoy it and preserve it well for years before undertaking a thorough cosmetic and mechanical renovation using the technology and methods most popular in the late ’80s and early ’90s. As the next steward, I have attempted what is commonly done today by mimicking an appearance as close to factory original as modern methods allow.”

Harley-Davidson Knucklehead Model history

A brief overview of the Knucklehead’s development goes like this. Prior to the early 1930s, Harley-Davidson’s large displacement V-twin engines featured flathead, or side valve, technology. In the mid-1920s, however, the Motor Company had offered the BA, or “Peashooter” model, with either flathead or overhead valve layout. Powered by a 21 cubic-inch single-cylinder engine, the BA was a limited-production model built solely for racing. By the early 1930s, however, riders of the company’s bread-and-butter road-going machines were requesting more power. In order to modernize their V-twin powerplant and meet the power demand, Harley-Davidson set its engineers to work designing an overhead valve V-twin powerplant that could be put into production.

During the height of the Depression era, even though motorcycle sales had dramatically tumbled, Harley-Davidson carried on developing an OHV engine. Instead of the total-loss oiling system found in their flathead twins, the new engine was given dry-sump lubrication. This featured a double-gear pump located at the rear of the aluminum crankcase delivering oil to the internal components and overhead valvetrain before returning the fluid to a separate tank for continuous circulation. Harley-Davidson had running prototypes late in 1933, and continued development through to 1935, when their new OHV layout debuted at a dealers’ meeting at the Schroeder Hotel in Milwaukee in November of that year.

As launched to the public in 1936, the new motorcycle was a 61 cubic-inch ironhead V-twin with 3-5/16-inch by 3-1/2-inch bore and stroke. The model E had a 6:1 compression ratio, while the EL was slightly higher with 7:1. There was only a difference of 3 horsepower between the two, with the E producing 37 and the EL making 40, both at 4,800rpm. Fork-and-blade connecting rods rotated on 1/4-inch caged roller bearings on the 1.125-inch crankpin between beefy 8.125-inch diameter flywheels. Overhead rocker gear that had finally been fully enclosed by the time of production — but was still prone to seepage — was operated via four separate pushrods riding on a four-lobe cam located in the right-hand side timing chest.

A new double downtube frame and twin-leg springer fork completed the new Harley-Davidson, and only 1,700 E and EL models were built in 1936. Changes were being made almost continuously in those early days of production. There was a total of three different timing covers fitted, two kickstarter gearing ratios installed and ignition timing also altered. As well, a total of seven different oil tanks were used together with revised oil lines, improved rockers and rocker oil feed, valve springs and five different modifications to the frame. Harley-Davidson didn’t sell many of the overhead valve models at the start, but as the machine was refined, customers began to appreciate the technology.

By 1941, Harley-Davidson boosted engine capacity to 74 cubic-inches, and offered that as the model FL. The 61 cubic-inch EL, such as Tony’s machine, was still available and the Knucklehead was in production until 1947, when Harley-Davidson introduced an updated model with alloy cylinder heads and upside down pan shaped rocker covers. The earlier model, with rocker covers that resembled the knuckles of a fist, was dubbed the Knucklehead by Harley-Davidson enthusiasts while the newest was called the Panhead.

Tony’s Knuck

As purchased by Tony, the Knucklehead was a good runner and rider. The two-tone red and white paint, while not correct, was in good condition and Tony familiarized himself with the starting and riding procedure and kept Carl’s Knucklehead pretty much the way it was for more than eight years. During those eight years, Tony rode the motorcycle close to 8,000 miles while collecting correct parts and pieces prior to starting a complete restoration to return the machine to factory-correct specifications.

“The way it left the factory is some indication of history in tangible form right in front of me in my garage that I can look at, enjoy and ride,” Tony says, “I would attempt to mimic the history book as much as possible, because that’s what it is to me, a piece of history that tells a story.”

Tony is a capable wrench who has rebuilt and restored several motorcycles. However, as this Knucklehead was his first Harley-Davidson, he wasn’t as familiar with the brand and in 2021 commissioned Mike Lichner of Knucklehead Motorworks to take on the bulk of the work. Mike’s shop was located in Muskego, Wisconsin, at the time. Now retired, he has moved to North Central Tennessee. Only occasionally does Mike now take on repairs to help keep old American iron in running condition.

To start the restoration, Mike removed many parts of the Knucklehead, including the tinwork, and gave them to Tony. Getting his hands dirty, Tony took on the task of cleaning and prepping many pieces to hand off to his painter, Jason LeCavalier of Artistimo Customs in Waukesha, Wisconsin. Jason took on any sheet metal repairs before proceeding with priming and painting them Skyway Blue, a Harley-Davidson factory color. Carl’s daughter Carolyn told Tony the bike had been blue before being re-painted red and white, and Tony confirmed this after locating evidence of the hue under a screw head on the rear fender, and under the chrome bezel of the front fender light.

Meanwhile, Mike pulled the 61 cubic-inch Knucklehead engine which had some oil leaks and a couple of broken fins on one of the iron cylinder heads. The engine was taken completely apart to check internal components, and all repairs, including a new pinion shaft, trued flywheels and new bearings went into cleaned cases with fresh gaskets. Up top, cylinders were honed and fitted with plus-.040-inch pistons and rings. Also installed were new lifter rollers, an Andrews camshaft, new exhaust valve guides and new intake and exhaust valves. For increased longevity, the heads were sent to Advance Cycle Machining in Superior, Wisconsin, for the installation of hardened valve seats. Mike ran the rebuilt engine in a test stand to sufficiently break it in before any serious road use.

While the engine was out, Mike further stripped the machine to the bare frame in order to have the front downtubes repaired. With such a low ground clearance, Tony says over time many Knucklehead frames received front downtube damage at the lowest point where they curve to go under the engine. For this specialized work, the frame was shipped to Wasco Frame Service in Tacoma, Washington, where the tubes were cut out and new ones were welded into place. With the frame shipped back, Tony had it and many of the other black components painted black. Very little was powder coated, in fact just the twin-passenger Buddy seat pan and springs (not fitted to the machine as photographed here).

Tony had Reliable Plating Works of Milwaukee de-chrome several pieces, including the front and rear crash bars, handlebar, derby cover and license plate bracket. One of the only parts he had re-chromed was the front fender light.

Harley-Davidson Knucklehead restoration: Nuts and bolts

As Mike put the Knucklehead back together, Tony opted to fit 18-inch rims to original Harley-Davidson hubs. In 1941, H-D had introduced 16-inch wheels front and rear, and Tony’s Knucklehead was rolling on chrome 16s. However, he much prefers the look of the slightly taller 18-inch wheels and built and trued both himself. Any incorrect fasteners were removed and replaced with proper items, and fasteners were glass beaded in preparation for refinishing. Originally Parkerized black, Tony bought a Parkerizing kit to perform the fastener refinishing process at home, while Mike also re-Parkerized many nuts and bolts.

A faithful aftermarket wiring harness was used in the restoration as Mike pieced the bike back together with the original ignition system and 6-volt electrics. Although Tony had the Buddy seat recovered, he prefers the look of a solo-style seat and bought a reproduction in Dark Umber to complete his Knucklehead. After 18 months of work, with plenty of help from Mike, Tony says he had a running Knucklehead back in his garage. However, he had a little trouble getting the engine to run happily when under power. The issue was traced back to the Linkert carburetor, and this was sent to Matt Olsen of Carl’s Cycle Supply for a full refurbishment.

Now, to bring the Knucklehead to life, Tony retards the spark about halfway, turns on the fuel, gives it full choke, cracks the throttle slightly and kicks the engine through twice on the compression stroke. Next, he turns on the ignition, reduces the choke to one click open, and gives it one good swift kick. The engine fires every time, he says, and once running, the ignition is fully advanced. “It’s very, very predictable to start,” Tony says. With a left foot clutch and hand shift lever on the left side of the gas tank, Tony doesn’t find the Knucklehead difficult to ride at all, and in the summer of 2022, added more than 500 miles to the refurbished machine. He says, “I dream of going farther on the bike, and wouldn’t discount it, because I think it’d go the distance.”

Tony concludes, “As the next steward of this bike, I hope to have given it the attention to detail that Carl did. I would have loved to have met him and have enjoyed speaking to and getting to know his daughter Carolyn and her spouse John. I greatly appreciate Carl Schmidt’s fascinating lifetime, and his wartime bravery. I’m proud to own his Knucklehead.” MC

Originally published as “Pride and Joy” in the July/August 2023 issue of Motorcycle Classics magazine.