The one-of-a-kind 1916 Traub is widely regarded as the rarest motorcycle, with a single surviving example on display at Wheels Through Time.
Rarity in motorcycles isn’t just about price. It hinges on how many exist, whether a factory or builder made it once and never again, and if the survivor you can see today is authentic. To answer which is the rarest bike in the world? we start with the bikes that exist in a count of one, then stack them against short-run legends built in tiny numbers. You’ll leave with a clear pick and the context to explain it.
Which Is The Rarest Bike In The World? Decision At A Glance
Among documented machines you can visit today, the 1916 Traub stands alone. It’s the “only one known,” runs under its own power, and sits in a public museum collection. That combination—single surviving unit, working condition, and public access—makes a strong case for the crown.
| Motorcycle | Why It’s Rare | Known Count |
|---|---|---|
| 1916 Traub | Hand-built mystery machine; sole survivor housed at Wheels Through Time | 1 |
| 1934 BMW R7 | Factory prototype restored by BMW; never produced | 1 |
| Harley-Davidson “Serial Number One” | Oldest known Harley-Davidson motorcycle | 1 |
| Winchester Motorcycle (c. 1911) | Badge-engineered oddity; scarcely documented | ~2 |
| Britten V1000 | Hand-built racers by John Britten’s team | 10 |
| Crocker V-Twin | Los Angeles performance twin built in tiny numbers | ~72 |
| Brough Superior SS100 | Custom-built pre-war superbike | ~383 |
Rarest Bike In The World: Criteria That Decide It
Ask ten collectors what counts as “rarest” and you’ll hear ten angles. To keep this practical, use four plain rules: production run, survivorship, documentation, and public visibility. Bikes that score on all four climb to the top.
Production Run
One-off prototypes and hand-built specials sit above limited editions. If a factory produced only one, that sets the ceiling for rarity. The 1934 BMW R7 fits that mold—designed, built, then stored for decades, with no duplicates known.
Survivorship
Counts at launch are only half the story. Many early machines were ridden hard, scrapped, or parted out. When a model’s survivors shrink to a single machine, rarity spikes. The Traub isn’t rare because it was a short run—it’s rare because only one surfaced.
Documentation And Proof
Rarity claims need receipts: factory records, museum curation, or verifiable provenance. That’s why museum-held bikes matter; the paper trail is real, the machine is curated, and the public can verify claims without guesswork.
Public Visibility
A unicorn hidden in a private vault helps nobody. A unicorn you can see, hear, and study anchors the claim. When visitors can walk up to a one-off motorcycle and read its story, that’s the kind of rarity most riders care about.
Why The Traub Edges The Field
The 1916 Traub checks every box. It’s a single known machine, it runs, and it’s on view. The museum that cares for it starts and rides it for visitors, which means the bike isn’t just static—its engineering still breathes. Public broadcasters even call it the “world’s rarest motorcycle,” lending a clear, accessible reference point for riders who want a settled answer. If you came searching for the phrase “which is the rarest bike in the world?” you likely want a clean, defensible answer. This is it: the Traub.
You’ll see other bikes with sky-high auction prices or tiny production runs, but few can match a one-of-one machine that you can visit today. That’s the difference between a headline and a proof-backed conclusion.
Close Contenders Worth Knowing
Rarity isn’t a winner-take-all game. A few machines sit in the same neighborhood for different reasons. Here’s why they matter and how they differ from the Traub.
BMW R7: Factory Art Deco Prototype
BMW built the R7 as an Art Deco prototype in 1934. It never went into production, then spent decades packed away before a painstaking restoration. The result is one complete factory prototype—stunning, documented, and singular. You’ll see tributes and homages on modern platforms, which only underscores how rare the original is.
Harley-Davidson “Serial Number One”
This is the oldest known Harley-Davidson motorcycle. It lives in the company’s museum, preserved as the brand’s starting point. It’s one bike, not a model run, and that places it next to the Traub in sheer scarcity.
Winchester Motorcycle: Gunmaker’s Brief Foray
Under the firearms brand, a tiny batch of rebadged motorcycles surfaced in the 1910s. Only a couple are publicly documented. The line didn’t last, and the surviving bikes are seldom seen outside auction catalogs and museum loans.
Britten V1000: Ten Hand-Built Racers
John Britten’s small team produced ten V1000s. Each was assembled by hand with bold engineering moves, and several set records. Ten units isn’t one, but it’s still rarer than almost any production superbike you’ll meet.
Crocker V-Twin: Muscle In Small Numbers
Al Crocker’s performance twins from pre-war Los Angeles arrived in tiny batches. Surviving examples command massive sums, and the model’s reputation comes from speed, craft, and scarcity.
Brough Superior SS100: Pre-War Royalty
George Brough tested every SS100 himself. Hundreds left the works, which keeps it out of the “rarest” slot, but surviving examples are coveted and pricey. It remains a touchstone for handmade performance motorcycles.
Context You Can Use
When someone asks you in the shop or at a meet, a grounded answer beats name-dropping. Start with the Traub because it’s one of one, running, and on public view. Then add that a few factory prototypes and earliest-known machines, like BMW’s R7 and Harley-Davidson’s Serial Number One, also exist as single, preserved bikes. Price at auction doesn’t settle the question; surviving count does.
Rarity Versus Price: Why They’re Not The Same Thing
Expensive doesn’t always mean rare. Some record-setting auction bikes are valuable because they’re famous, pristine, or linked to a household name. Others brought big money due to a one-time bidding battle. True rarity is about existence and proof. A one-off prototype with a clear paper trail can be far rarer than a glittering special edition that sold in the hundreds.
Flip it the other way and you’ll see the trap. A costly superbike with numbered plaques might feel exclusive, yet hundreds of owners share it. That’s special, but it’s not a single survivor. If the question targets the single rarest motorcycle, one beats many every time.
How Collectors Prove A Rarity Claim
Serious collectors love paperwork. Build sheets, archive letters, period photos, and museum files are the backbone of any claim. If you’re weighing a rarity statement, look for these basics: a traceable chain of ownership, authentication by a respected curator or marque expert, and a verified location where the bike resides. When those pieces line up, the claim carries weight.
What Counts As A “One-Off”
Two categories matter most: factory prototypes and singular private builds. Factory prototypes usually come with drawings, internal memos, and period images. Private builds can be tougher; the best cases include dated letters, news clippings, and eyewitness accounts tied to a specific shop and maker. The Traub’s story includes period registration evidence and decades of museum stewardship, which is why it holds up under scrutiny.
Care, Preservation, And Why Running Matters
A motorcycle that starts and rides proves more than a static display. It confirms completeness, correct assembly, and mechanical health. Museums that maintain one-off machines in running condition add a layer of confidence. Bearings wear in, gaskets seal, and systems show they work together. For a claim as strong as “the rarest in the world,” that kind of proof is gold.
| Place | What You’ll See | Tip |
|---|---|---|
| Wheels Through Time | The Traub, started by staff on select days | Arrive early on demonstration days |
| Harley-Davidson Museum | “Serial Number One” and early board-track racers | Book a guided tour for deeper detail |
| BMW Heritage Appearances | Restored R7 prototype at invited events | Watch major concours schedules |
| Major Auctions | Crockers and Brough Superiors | Preview days let you study bikes up close |
| National Collections | Britten V1000s in rotating exhibits | Check museum listings before you travel |
Spotting Claims That Don’t Hold Up
Some bikes are rare trims, paint codes, or markets. That’s neat, but it’s not the same as a unique machine. When you see sweeping statements, ask three quick questions: How many were made? How many survive? Where can I see proof? If the answers get fuzzy, treat the claim as marketing, not history.
Travel Notes And Handy Links
Planning a trip to see the Traub and other one-offs? Start with the museum pages. The Traub runs at Wheels Through Time in Maggie Valley, and public broadcasters profile it as the world’s rarest motorcycle. In Milwaukee, the oldest known Harley anchors the galleries; the museum’s exhibit pages introduce “Serial Number One” and set the scene for early factory history—see the official Harley-Davidson museum exhibits.
Method In Brief
We compared single-survivor bikes to ultra-low runs. We weighed survivorship first, then documentation and public access. The more boxes a motorcycle ticks, the closer it gets to the top spot.
Bottom Line
The clearest answer to the query “which is the rarest bike in the world?” is the 1916 Traub. It’s the only one, it runs, and you can stand beside it. Factory prototypes like BMW’s R7 and first-of-the-line pieces like Harley-Davidson’s “Serial Number One” make a tight inner circle, but the Traub keeps the crown.