The One is the next evolution of handcrafted carbon frames from Open, incorporating new shapes, layups and in-house production (in Germany) to create a remarkably light mountain bike frame weighing in a less than 850 grams. If you’re metric adverse, that’s well under two pounds.
Open is the brainchild of Andy Kessler (former CEO of BMC) and Gerard Vroomen (Co-founder of Cervelo). As such they have long worked toward building the ultimate products at any price.
The dropped drive-side chainstay allows it to move out of the way between the chainring and tire. The seat stays are thin and slightly bowed, which gives great vertical compliance. The BB30 bottom bracket means there are lots of options for cranks, and the Syntace 142mm thru-axle rear is held in place by a small insert with an attached derailleur hanger and a cap.
To keep the frame as light as possible there is no paint and very few graphics. You can see the different layups of carbon in key areas. Keeping the weight down on this complete bike are carbon bits from AX Lightness and the new RockShox RS-1 fork.
The frame can even run a front derailleur, with a high direct mount. It is also ready for electronic drivetrains, as many Open Cycle bikes have been built with Shimano Di2 systems and the K-Edge adapters for mountain bike gearing. All the cables or wires enter the frame at the head tube, and different inserts can be used for the plug, depending on the build.
The One frame is designed with no limitations on materials and construction, and it’s made in Germany, so the sticker price might be a bit out of reach at $4,800. But Kessler says it’s only the first step toward his ultimate goal of building world class mountain bike frames in Germany at an approachable price. It will be available in July in very limited quantities and only as a frame-only.