By Kevin Rouse

Open Cycles O-1.0

$2,700 (frame only)
$6,500 (Unlimited Edition)
$12,000 (Limited Edition Hydraulic)

Industry veterans Gerard Vroomen (Co-founder of Cervélo) and Andy Kessler (Former CEO of BMC), have partnered together in an interesting new venture dubbed Open. With the launch of their O-1.0 hardtail, the nascent brand has already made a name for themselves, claiming the bike to be the lightest 29-inch production hardtail on the market.

But just how light is it? Open claims that for their size medium frame, the scale registers just 850 grams. (In fact, several frames have come in well under that--a size medium was present at Sea Otter that weighed just 828 grams.) A complete bike built with SRAM’s top-tier XX group (and XX-level SID fork) and Rotor cranks weighs just 18.2 pounds sans pedals.

Featuring novelties such as fully internal cable routing and electronic and hydraulic (The top-tier, $12,000 O-1.0 ships with Acros’ hydraulic drivetrain) drivetrain compatibility, It’s clear Vroomen and Kessler weren’t simply playing follow the leader with their latest project either.

The use of the BBright bottom-bracket standard limits crank choices considerably unless you choose to use an adaptor, but the the system has already been proven to be incredibly stiff--as evidenced by the standard’s application throughout Cervélo’s road lineup.

The wire-thin seatstays, as well as the chainstays were designed to provide vertical compliance while still being able to maintain plenty of torsional rigidity. Also novel is the Open’s chainstay-mounted brake posts, which, together with a carbon bridge that stems from the left dropout and connects the two posts, help reduce unwanted frame flex derived from braking forces.

Anyone familiar with the road side of the game knows that Cervélo is on the forefront of carbon technology, and behind that technology is much of the work of Gerard Vroomen. Case in point is Cervélo’s Project California road bike: a bike that is unbelievably light, yet still retains all of the desired ride qualities. But what does this have to do with the mountain bike side of the aisle?

To look at it in a different light, a road bike subjected to the cobbles of Paris-Roubaix actually sees more impact force than a hardtail mountain bike, due to the mountain bike’s much larger tire size being able to absorb much more of the impact forces. Thus the two founders of Open looked to their outsider status as a benefit, rather than a hindrance, in their quest to design and manufacture the lightest production hardtail on the market. But while the end result is a bike that is without doubt quite a feat of engineering excellence, it remains to be seen whether the rest of the equation is present as well.

Addressing this, Vroomen and Kessler cite an enormous amount of effort being poured into the more intangible aspects of the bike--like its geometry and handling feel. Kessler was a former pro downhiller, so its not fair to say the duo is entirely removed from the mountain bike world. Although, we are interested to see how the bike feels for ourselves as the 72-degree headtube angle is seemingly pretty steep--even for the über-aggressive race-whip category.

The Open O-1.0 is available now, though only size large. All other sizes will be available by the end of June, and will be sold through a dealer network of roughly 50 brick-and-mortar dealers nationwide. Online, the O-1.0 is available exclusively through Competitive Cyclist.