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Vintage Bicycles: 1983 Mantis XCR – A Rare Machine

A rare machine, this 1983 Mantis XCR tells the story of the then-nascent Southern California mountain bike scene. The movement that grew out of Marin would eventually bring radical and different ideas to mountain bike design the world over. In tandem with founding Mantis Bicycles in 1981, Richard Cunningham’s first production racing mountain bike would serve as a catalyst to the burgeoning mtb scene, and stand in contrast to more traditional Marin-born frame designs. For the next ten years he would relentlessly innovate, exploring geometry, materials and design along the way. Read on for more of Noah Gellner’s words with photos by Joey Schusler

The Beginning

Even before he began working on bikes, Richard Cunningham had a natural talent for inventing, tinkering, metalwork and design. At age 23, he opened his own machine shop and quickly developed a reputation for the quality of his work and his knack for ideas. Working on Porsche 934s, and fabricating custom ducting for these racing machines, became an early area of expertise for Cunningham.

Although work kept him busy, he continued to carve out time to fabricate parts for auto aficionados whose restoration projects posed unique challenges. During these transformative years, Cunningham was also devoting increasing amounts of time to riding his road bike, enjoying the tranquility of logging increasingly bigger miles.

While his riding preferences were mostly touring-focused, he tried his hand at a few different styles of racing: he mixed it up on the road, dabbled at dirt bike racing, and once even lined up next to Steve Potts! Still, on long days spent astride his touring bike, he felt the call of the dirt roads. Similar to Charlie Cunningham (no relation) when the first alloy rims for fat tire bikes became available, Richard was ready to make the move off-road.

Richard’s prior body work on rare racing and collectible automobiles had honed his craft and given him familiarity with different materials, perfectly preparing him to launch into the world of bicycle framebuilding and design. Alongside his firmly-held passion for bicycles, his motocross time helped him anticipate certain performance considerations specific to mountain bikes. To top it off, Richard’s innate creativity and ingenuity would also play a pivotal role in all his cycling contributions.

Richard Cunningham was inducted into the Mountain Bike Hall of Fame in 1995, the year after Mantis was sold and already a couple years into his stint as editor at Mountain Bike Action. He continues to be involved in the cycling world as a journalist and editor across cycling publications, as a land access activist and as a member of the induction and selection committee of the Mountain Bike Hall of Fame.

Mantis

While the NorCal crowd had adopted their Marin geometry from klunkers and the demands of bombing down fire roads, Richard used classic road bike geometry as his design starting point. In fact, his earliest builds had a 72° head angle and a 74° seat angle, a combination he admitted resulted in extremely squirrely handling going down hill (though years later, John Tomac’s Mongoose Signature famously used these extreme numbers in a bike that only he could master). Richard quickly adjusted his geometry, moving to parallel 72° degree angles. Additionally, compared to the classic Marin geometry, his bikes also had much shorter chainstays. Overall, Mantis bikes were built to be fast from day one, whether the rider’s intended use was between the tape or touring.

Mantis formally launched in 1981 and by 1983 the line-up included three standard models. There was the luxurious, touring-oriented Sherpa, its more economical TIG-welded cousin, the Overland, and to round out the set, the XCR was built for racing.

At that time, XCR stood for “cross-country racer.” By 1984 the fillet brazed steel frame had been replaced by an aluminum main triangle with a cro-moly rear triangle bolted on. This design was licensed to Fisher for its CR-7  (with CR now standing for Composite Racing). This same design was also later licensed to Nishiki for its Alien ACX elevated chainstay bicycle. The XCR model was produced in different forms until being discontinued in 1993, the year before Mantis was sold. The unifying theme for this model was a continued focus on creating a nimble and durable racing platform.

1983 XCR

The stock color for the 1983 XCR was a flashy red Imron (it was a racing bike after all). Geometry-wise, Richard noted that it was nearly identical to Fausto Coppi’s championship Bianchi. This bike featured in these photos, however, has a more subtle custom blue finish.

It took some extensive searching to unearth an available frame from this rare, single-year fillet-brazed run. As you might expect, the pristine specimen you now see here was it rough shape when it was initially discovered— it had been ridden hard and put away wet. Bringing the bike back to its former glory was a multi-year restoration project taken on by Second Spin Cycles, an expert with Mantis frames (see the complete resto process here.) With the original finish beyond salvaging, a Mantis XCR housed at the Shimano bike museum served as inspiration for the finish and much of the restoration more broadly.

Build Specs

  • Year: 1983
  • Frame: Fillet-brazed cro-moly with Columbus stays. Richard’s “peaked” fillets were a trademark flourish.
  • Fork: Mantis Bi-Plane
  • Stem: Mantis
  • Handlebars: Cro-moly
  • Grips: WTB modified Magura
  • Headset: Specialized steel
  • Shifters: Suntour
  • Front Derailleur: Suntour MounTech
  • Rear Derailleur: MounTech
  • Brake Levers: Magura motorcycle
  • Front Brake: Shimano Deerhead M700
  • Rear Brake: Shimano Deerhead M700
  • Crankset: Modified Campagnolo
  • Bottom Bracket: Press fit Phil Wood
  • Rear Tire: IRC Racer X-1
  • Front Tire: IRC Racer X-1
  • Wheelet: Ambrosio Durex with Phil Wood steel hubs and Campagnolo quick releases
  • Seatpost: Modified Shimano DX post
  • Saddle: Selle San Marco Anatomica
  • Chain: Sedis
  • Cogs: Suntour Winner
  • Seat Quick Release: Modified Campagnolo
  • Pedals: Suntour XC