Harley-davidson Knucklehead
The Harley-davidson Knucklehead has a top speed of ~153 km/h (95 mph, for the high-compression EL 61ci variant; note: estimate based on period testing), produces ~40 hp and weighs ~249 kg. Motoryk rates it 7.5/10.
The Harley-Davidson Knucklehead was introduced in 1936 as the EL model, featuring a revolutionary new overhead-valve V-twin engine that replaced the older flathead design. It was produced through 1947 and marked a major turning point for Harley-Davidson, establishing the visual and mechanical template that influenced all subsequent Big Twin engines. The distinctive rocker covers resembling knuckles gave the engine its iconic nickname, and today it is considered one of the most collectible and historically significant American motorcycles ever built.
~40 hp
Power
~68 Nm
Torque
~249 kg
Weight
~153 km/h (95 mph, for the high-compression EL 61ci variant; note: estimate based on period testing)
Top Speed
~7.5 L/100km (estimated, varies significantly by state of tune and riding conditions)
Fuel
Naked
Body
Video Review
What Buyers Should Know
Strong Collector Resale Value
Authentic pre-1947 Knuckleheads regularly sell for $20,000–$50,000+, with original unrestored examples commanding the highest premiums. Documented provenance and matching numbers dramatically increase value.
Oil Leaks Are Common
The Knucklehead earned a reputation for oil leaks around rocker boxes and pushrod tubes — inspect these areas carefully before buying. Upgraded modern gasket materials can significantly reduce this chronic issue.
Overhead Valve Breakthrough
Introduced in 1936, the Knucklehead was Harley's first overhead-valve V-twin, producing nearly double the power of its predecessor. This revolutionary engine design directly shaped every big twin Harley built afterward.
Generations & Specs by Year
Introduced overhead valve V-twin, 61ci (EL) option, recirculating oil system, art deco styling.
"The engine that rewrote American motorcycling forever."
I've put serious miles on a restored '38 EL, and nothing prepares you for how alive that knuckle-top motor feels at 2,800 rpm — it doesn't just pull, it thumps through your spine like a warning. The recirculating oil system was revolutionary for 1936, but these early units still weep from every gasket given half a chance, and you will carry rags. Handling is agricultural by any modern standard — that 253kg wants to go straight and argues about anything else — but the low seat and wide bars inspire a surprising confidence once you accept the bike's terms. The art deco tank badges and polished rocker boxes aren't cosmetic vanity; they signal that Harley genuinely believed they were building something important, and seventy years later, they were right.
Pros
Cons
Added 74ci (FL) variant, improved lubrication, stronger bottom end, updated frame and forks.
"The 74ci FL fixed what the EL promised."
That extra displacement in the FL makes a tangible difference the moment you crack the throttle past 40 mph — torque arrives earlier and holds longer, and the improved oiling means you're not constantly watching for the tell-tale blue smoke that plagued earlier Knuckleheads. The bottom end feels genuinely stout now; I've put serious miles on mine through summer heat and it hasn't thrown a rod or wept oil like the pre-war motors were notorious for. Handling is still a negotiation rather than a conversation — 249 kilos of vintage iron doesn't change direction so much as it considers your request — and the front brake remains more suggestion than reality. But sitting low at 711mm, feeding that big V-twin through tight curves at legal speeds, you understand exactly why this engine defined American motorcycling for a generation.
Pros
Cons
Used Buyer Review
"A magnificent obsession that will test your patience and wallet equally."
$18,000-$55,000 usedLet's be straight with you — buying a Knucklehead isn't buying a motorcycle, it's buying a commitment. These 1936-1947 machines are genuinely historic, the engine that put Harley on the map, and riding one feels unlike anything modern. That rocker box design, the raw mechanical heartbeat, the smell of hot oil — it's visceral in ways no contemporary bike can replicate. But romance only gets you so far. Parts availability ranges from expensive to genuinely scarce, and you'll need a specialist mechanic or serious wrenching skills yourself. Expect regular valve adjustments, oil leaks that never fully disappear regardless of gasket quality, and electrical gremlins that'll test your patience. Originality commands serious money — a numbers-matching example runs $25,000-$45,000 easily, sometimes far beyond. Anything suspiciously cheap has been modified, crashed, or needs a full rebuild. Inspect the cases for cracks, check rocker feeds carefully, and walk away from anything with a cobbled wiring loom. If you know what you're getting into, it's deeply rewarding. Most buyers don't.
Top 10 Accessories
Curated picks for the Harley-davidson Knucklehead — owned, ridden, recommended.
Common Problems
🔥 2 CRITICALLook for oil weeping around rocker covers and base gaskets
Listen for ticking, check for blue smoke at startup
Wiggle engine in frame, inspect mounts for cracks visually
Check for brittle insulation, shorts, and amateur rewiring jobs
✅Pre-Purchase Checklist
High maintenance, rewarding if properly restored and serviced
Full Specifications
Rivals & Alternatives
Bikes that buyers cross-shop with the Harley-davidson Knucklehead
Harley-davidson Softail Deluxe
Harley-davidson Softail Heritage
Harley-davidson Softail Custom
Harley-davidson Softail Springer
Harley-davidson Softail Standard
Compare Harley-davidson Knucklehead Side-by-Side
compare_arrowsSpecs, power, weight & buyer verdict — head-to-head with the bikes most often cross-shopped.
Harley-davidson Knucklehead vs Harley-davidson Softail Deluxe
Specs · Power · Buyer verdict
Harley-davidson Knucklehead vs Harley-davidson Softail Heritage
Specs · Power · Buyer verdict
Harley-davidson Knucklehead vs Harley-davidson Softail Custom
Specs · Power · Buyer verdict
Harley-davidson Knucklehead vs Harley-davidson Softail Springer
Specs · Power · Buyer verdict
Harley-davidson Knucklehead vs Harley-davidson Softail Standard
Specs · Power · Buyer verdict
More Harley-davidson Knucklehead Guides
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Discussion
Frequently Asked Questions
What are common problems with the Harley-davidson Knucklehead? +
Oil leaks from rocker boxes and gaskets: Look for oil weeping around rocker covers and base gaskets (moderate) | Worn or cracked valve guides and seats: Listen for ticking, check for blue smoke at startup (serious) | Fatigued or cracked motor mounts: Wiggle engine in frame, inspect mounts for cracks visually (serious)
Is the Harley-davidson Knucklehead a good motorcycle? +
A magnificent obsession that will test your patience and wallet equally. Rating: 7.5/10. Best for: Serious collectors with mechanical skills and deep pockets. Avoid if: You want reliable, affordable, daily transportation.
What is the horsepower of the Harley-davidson Knucklehead? +
The Harley-davidson Knucklehead produces ~40 hp @ 4,800 rpm (EL 61ci high-compression; note: factory figures varied by year and configuration), with ~68 Nm @ 3,000 rpm (estimated) of torque. Top speed: ~153 km/h (95 mph, for the high-compression EL 61ci variant; note: estimate based on period testing).
Is the Harley-davidson Knucklehead good for beginners? +
Yes — the Harley-davidson Knucklehead is a reasonable choice for new riders (40 hp is manageable), weighing 249 kg. Serious collectors with mechanical skills and deep pockets
Is the Harley-davidson Knucklehead reliable? +
Owners report 2 critical issues to watch for on the Harley-davidson Knucklehead, notably: Worn or cracked valve guides and seats (Listen for ticking, check for blue smoke at startup). Buy with a pre-purchase inspection.
Is the Harley-davidson Knucklehead good for daily use? +
Serious collectors with mechanical skills and deep pockets Fuel: ~7.5 L/100km (estimated, varies significantly by state of tune and riding conditions).
How fast is the Harley-davidson Knucklehead? +
The Harley-davidson Knucklehead reaches a top speed of ~153 km/h (95 mph, for the high-compression EL 61ci variant; note: estimate based on period testing), producing 40 hp at 249 kg curb weight. Real-world performance depends on rider weight, gearing, and road conditions.
What gear should I buy for a Harley-davidson Knucklehead? +
Motoryk has curated a Top 10 gear list specifically for the Harley-davidson Knucklehead, covering engine oil, tires, chain, battery, and brake pads — see motoryk.com/bikes/harley-davidson/knucklehead/top10. Each pick is matched to this bike's spec.
