BUILDING A HARLEY KNUCKLEHEAD CHOPPER: THE STUFF OF DISTANT DREAMS
Getting my hands on a Knucklehead always felt like a distant dream. They're rare, and owners usually hang onto them like gold—or if they decide to sell, the prices are through the roof.
1947 Harley-Davidson FL Knucklhead B-side
One Sunday morning, I was chatting with my buddy Rob Hultz and casually mentioned my struggle to find an affordable knuckle project. Maybe he sensed the desperation in my voice, but he mentioned that he had a 1947 FL roller just sitting around.
He's a collector, so I never expected him to offer up one of his projects to me but the stars aligned that following Wednesday when I brought home the core of this bike—a 1947 FL with matching bellies and a '49 Transmission.
It came with OEM 1947 gas tanks that are now proudly hanging on my wall, an offset springer, and a freshly rebuilt Linkert M74B. I swapped out the 16" rear wheel for an 18” that I snagged from Davenport.
Skinny, lean, and mean.
I instantly fell in love with the motor's patina—rust, flaking paint, and all—so I decided to match the tins using a painting technique I found online. My son pitched in, laying down some lines to give it that extra flair.
The original intake ports were shot, and I couldn't get it to run right. So I carefully removed and replaced the plumber-style intake ports with O-ring type. With the PCP Panifold, this bike is now running like a dream.
Check out that motor's patina
I raised the oil tank to get rid of the gap under the frame, which meant some fabrication work to extend the inner primary tab. The rear fender brace is salvaged from a hinged fender that I bent around the top of the fender.
The Knucklehead at Mama Tried 2022 Photo by Mikey Revolt
The bike has been in MamaTried 2022, Fuel Cleveland 2022, and a few local shows in Milwaukee and Chicago.
In the field at Fuel Cleveland 2022 - Photo by: Shane Spencer
DETAIL SHOTS OF CUSTOM 1947 HARLEY KNUCKLEHEAD
I've always been fascinated by Kiyo's knuckle featuring those sleek 3.5-gallon tank shift narrow split gas tanks. Initially, I considered seeking assistance from friends who work in fabrication, but I wanted to learn how to TIG weld.
Taking matters into my own hands, I proceeded to cut the tanks. Unfortunately, I overlooked the importance of the bottom clearance curves. To address this, I used one of Pangea's tracing techniques using masking tape and my fingers to outline the cutout shape.
Split tanks
The inner panels were from sheet metal, trimmed with an angle grinder, and refined with a ball-peen hammer to minimize gaps. Eager to master TIG welding, I purchased a welder setup and practiced for 10 minutes before diving in—a decision I later deemed a big mistake. In retrospect, starting with thicker gauge metal would have been wiser, as I spent months chasing pinholes.
close up of the gas tanks
To retain the stock mounts, I strategically spaced the tanks, ensuring accessibility to the backbone brackets. With the raised tanks, I added a mounting point to the country bar for increased stability. I then added a petcock bung to the left tank, centered between the jugs, positioned at the lowest point.
I welded barbs to the bottom/rear of each tank to equalize the fuel. Following a recommendation from my friend Matt Landman, I applied three coats of RedKote to seal the tanks. After drying, I pressure-tested the tanks to confirm pinholes are gone.
The jewel is off a belt buckle
I decided to run a modern ignition coil, I discreetly positioned it behind a late model coil cover, embellishing it with a jewel from a belt buckle gifted by my wife years ago.
I made the shifter and shaped a wheel spacer with an angle grinder, creating a knob with a curve that allows me to hook a finger when shifting.
Words and photos by Ken Carvajal
1947 Knucklehead
TECH SHEET: KEN CARVAJAL'S 1947 FL KNUCKLEHEAD
General
Owner: Ken Carvajal
Year/Make/Model: 1947 Harley-Davidson FL
Fabrication: Narrowed 3.5 gallon gas tank, Fender Strut, 7/8 handlebars, head and tail light, hand shift lever and knob, mounting brackets, relocated petcock bung.
Build Time: 1 year
Knuckle
Engine
Year/Type/Size: 1947 Knucklehead, 74 cubic inch
Carburetor: Linkert M74B / Phares Cycles PSP intake manifold
Exhaust: Gasbox exhaust pipes: Knucklehead upsweep shotgun
Air Cleaner: Linkert Bird Deflector
Repop straight leg knuckle frame
Frame
Year/Type: Repop Straight leg knuckle frame
Rake/Stretch: Stock
Off set springer
Front End
Type / Brand: OEM Style off-set Springer with springer cover plate.
21" front - star hub, drum brake
18" rear wheel - Star hub with moon disksWheels
Front Size: 21 inch star hub, Avon Speedmaster tire
Rear Size: 18 inch star hub, Avon tire with 18” moon disks.
can you say patina
Finish/Paint
Paint by: myself - DIY Patina. Pinstriped by my son Aden Carvajal.
Custom leather mud flap
Accessories
Front Fender: None. Custom leather mudflap by Drybrook / Leadfist Cycles
Rear Fender: Throttle Addiction repop K model fender
Gas Tank: Narrowed 3.5 gallon gas tanks and relocated petcock bung - centered between jugs. Pangea petcock with PCP O-ring Panifold by Jason Phares
Handlebars: 7/8’s Stellings style bars by Lovecycles, narrow angled Stellings & Hellings style top clamp by Arie Vee with Abel Brown angled risers.
Grips: Leather wraps
Mirrors: Nope.
Hand Controls: Super Pratic throttle
Foot Controls: Lee style foot clutch by Troels Madsen (Denmark)
Headlight: 4 1/2” swap meet special, modified to fit LED bulb, mounting and toggle switch.
Taillight: Guide bullet light modified to run dual filament LED bulb. Another swap meet item.
Turn Signals: Nope.
License Mount: Hose clamps.
Seat: Rocky solo leather seat.
Charging System: Cycle Electric DGV-5000L
MORE PHOTOS & DETAIL SHOTS
1947 Harley-Davidson
Gasbox upsweep shotgun exhaust
Through the bars
Leather grips
Oem Replica Offset Springer
Rocky solo seat
Detail shot of mud flap
Floorboards
Dogbones
4 1/2" swap meet find on the headlight
Throttle housing
Perfect place to hide a guardian bell
split tanks
Manifold
Rear fender
One lonely taillight
Custom Jokey Shifter
Another look at that coil cover
handlebar setup
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