OPEN the Possibilities
This frame is incredibly versatile, and further blurs the line between road and mountain bike disciplines as a class leading cyclocross bike. The 3 members of the U.P. (Unbeaten Path) range from OPEN all combine a road riding position with clearance for mountain bike tyres. Get yourself out of town on an adventure. Leave home on asphalt, then start grinding up gravel roads or carving down some flowy singletrack. Your riding position gets you there quickly and efficiently; the big tyres give you the grip and confidence you need to feel unstoppable.
This frame fits 27.5” (650B) mountain bike tyres up to 2.1” wide. But you can also fit a 40mm cross tyre, or a 28mm road tyre, or anything else in-between (exact tyre sizes depend on manufacturing tolerances and rim width, so this is a guideline. Always make sure you have 6mm clearance between tyre and frame).
You’ll hardly notice a difference in geometry swapping 700c cross/road and 650b mountain bike tyres on this frame.
This frame sports a very short 420mm rear end, designed to accommodate 650B wheels rather then 29inch, enabling much quicker, more responsive handling.
Dropping the right chainstay away from the crowded area behind the bottom bracket let OPEN build it wider and therefore stiffer (a huge effect; with the same amount of material, twice the width will give you eight times the stiffness!). A solution to dealing with the fight for space between the chainrings, frame and tyre.
Making a frame entirely out of 100% high modulus (stiff) carbon is not a good idea, especially when there are areas like the headtube that receive big impact loads. Stiffer carbon is more brittle, so it’s not appropriate for all parts of a frame. OPEN have used the stiffest carbon of any bike manufacturer in areas where possible, and used tougher, slightly more flexible grades of carbon where needed.
Lateral stiffness in the rear triangle is required for an efficient drive train, but vertical compliance allows for better comfort. This frame features chainstays and seatstays that are exceptionally thin vertically to give you that compliance, whilst their lateral width and carbon fibre layup still ensure rock-solid propulsion. Truly the best of both worlds.
The downtube is the key for stiffness, connecting the steering centre of your frame with the drivetrain. The flat-out downtube’s characteristically flat outside faces allow us to strategically place strips of ultra-high modulus carbon far away from the centre plane.
Zero-setback seat tube
The seat tube angle is designed around the use of a straight, zero-setback seatpost rather than a regular seatpost with setback . Zero-setback posts are lighter, saving you another 10-30 grams.
With MultiStop design, you can customize the frame for 2x10/11, 1x10/11 and Di2 shifting. Just pick the right insert. If you run a single chainring, you can also remove the front derailleur hanger to further clean up the frame.
OPEN designed a new fork that accepts flat-mount calipers without the need for an adapter. So you can get your Shimano or SRAM flat-mount caliper, remove the standard adapter it comes with, and bolt it directly onto the fork.
This saves weight and increases the stiffness of the braking system.
But the U-turn fork doesn't just save you weight on the flat-mount brake, it is also extremely light itself. At 375 grams, it is by far the lightest fork that fits GravelPlus tyres. And to save even more weight, it is comes with an extremely light 12mm Carbon-Ti custom axle
Top tube bag mount
For handy storage of your phone, camera, some tools or food, you can use the top tube bag mounts.
The U.P. uses the 386 EVO bottom bracket standard. The wide (86mm) BB shell is perfect to attach the dropped drive-side chainstay to. Furthermore, it fits most of the cranks on the market, from Shimano and SRAM but also smaller brands like THM and Rotor. 386 EVO even allows for the installation of many mountain bike cranks.