Superlight version of the U.P. Combines performance-oriented road geometry & parts with clearance for mountain bike tires. Start on asphalt, try gravel, hit single track. Its geometry makes you fast; its tires unstoppable. The U.P.P.E.R. accepts flat-mount brakes and ships with an OPEN U-turn fork.
In the box: Frame, fork, headset, seattube collar, front & rear Carbon-Ti thru-axle, 2 derailleur hangers, 1 front derailleur mount, 3 MultiStops (2x, 1x, Di2), chainstay cable exit, BB guide, cable liners, noise-reduction foam sleeves.
Click here for Geometry Chart
Click here for Specifications
Tire clearance
The U.P. fits mountain bike tires up to 2.1” wide. But you can also fit a 40mm cross tire, or a 28mm road tire, or anything else in-between (exact tire sizes depend on manufacturing tolerances and rim width, so this is a guideline. Always make sure you have 6mm clearance between tire and frame).
Below is the outside radius for various wheel+tire combos:
| Radius |
Rim |
Tire |
| 341mm |
700c/29er |
28mm road |
| 344mm |
700c/29er |
32mm cross |
| 350mm |
700c/29er |
40mm cross |
| 342mm |
650b/27.5" |
2.1" mtb |
| 365mm |
700c/29er |
2.1" mtb |
As you can see, the top-4 wheel+tire combos (700c cross/road tires and 650b mountain bike tire) are very close in radius, the bottom one (the 29er mountain bike tire) is way off.
So you'll hardly notice a difference in geometry swapping 700c cross/road and 650b mountain bike tires on the U.P., while 29er tires would make a total mess of the handling.
There is a second reason Open designed for 650b and not 29er tires. They would require very long chainstays, while the U.P. now sports a very short 420mm rear end. Most gravel and cross bikes have longer chainstays than that yet they can't fit anywhere near the same size of tire.
Crank clearance
Behind the bottom bracket, the chainrings, frame and tire all fight for space. And with the need to fit big mountain bike tires and narrow Q-factor cross/road cranks & chainrings, the U.P. presents the toughest possible packaging problem.
Dropping the right chainstay moves it out of this crowded area, allowing it to be wider and therefore stiffer (a huge effect; with the same amount of material, twice the width will give you eight times the stiffness!).
TRCinTRS™ technology
“100% hi-modulus carbon”, “aero-space grade”, etc. Useless – and hopefully false (we'll get to that) – claims meant to impress you.
It's not about high- or low-modulus, it's about the right carbon in the right spot. And because the bike industry loves techie-sounding abbreviations, we'll humor them and call it TRCinTRS™.
Fact: stiffer carbon is more brittle. Strategically placed ultra-high-modulus carbon is a good idea. Making the whole headtube out of it when you have big impact loads is not!
The best lay-up is not 100% of one modulus; it's a blend. Open use the highest modulus (stiffest) carbon of any bike manufacturer where they can, and tougher grades of carbon where they must. That's how our frames are both light and durable.
For the U.P. and the U.P.P.E.R., Open use different lay-ups, meaning the shapes of the plies and the ratio between the different materials is different for the two models, with the U.P.P.E.R. using an extremely complex lay-up.
Wire-stays
The rear triangle has to provide lateral stiffness for an efficient drive train, but vertical compliance for better comfort. The U.P. features chainstays and seatstays that are extremely thin vertically to provide that compliance, while their lateral width and layup ensure rock-solid propulsion. Truly the best of both worlds.
Flat-out downtube
The downtube is the key for stiffness, connecting the steering center 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 center plane. The stiffest carbon exactly where it matters, guaranteed!
Zero-setback seattube
With a minimalist 27.2mm diameter Open maximize the flex in our seatpost & seattube. This is especially a big plus on rough terrain. The seattube angle is designed around the use of a straight, zero-setback seatpost rather than a regular seatpost with setback (we've never understood those). Zero-setback posts are lighter, saving you another 10-30 grams (every little bit helps and you can then put that saved weight into a 500g saddle like the Brooks!).
Fully-internal cables/hoses
External cables & hoses collect dirt, risk getting stuck behind objects (particularly expensive with electronic shifting) and frankly, they are ugly. So the U.P. runs them internally.
With our proven MultiStop design, you can customize the frame for 2x10/11, 1x10/11 and Di2 shifting. Just pick the right insert. In case you run a single chainring, you can also remove the front derailleur hanger to further clean up the frame.
ThruThread dropouts
Most thru-axle frames are heavier than quick-release frames. Extra carbon for the dropouts, heavy hangers, and the axle itself. But they are stiffer, So what do you want most? The answer for most people is “both”, and so Open introduce the first frames that combine a thru-axle with a lower weight. How?
The ThruThread design uses the same threads that hold the thru-axle to lock the derailleur hanger into the frame. Simple, light, effective.
They didn't just redesign the dropout, the entire seatstay and chainstay design is optimized with the added stiffness of the thru-axle in mind. For the thru-axle itself, Open recommend the stiffest design available, the Syntace X-12, but you are free to use a different 12mm thru-axle if you want.
Disc brake mounts
One of the key differences between the Classic U.P. on the one hand and the new U.P. and U.P.P.E.R. on the other is the disc mount standard. The Classic U.P. uses post-mount, the other two are designed for flat-mount. Open don't like how the bike industry keeps “inventing” new standards, so Open always investigate if they are an improvement before they use them.
Post-mount brake calipers work very well, and the main argument for flat-mount is that it looks better (sigh) while a significant drawback is that the front brake always requires an adapter for mounting, adding weight and reducing braking efficiency.
U-turn
For the U.P.P.E.R., 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 our fork.
This saves weight and increases the stiffness of the braking system.
They do this by making the fork dedicated for 160 mm brake rotors (140 mm is a bad idea anyway on this type of bike) and using the same through-bolt design that is normally reserved for the rear.
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 tires. And to save even more weight, it is comes with an extremely light 12mm Carbon-Ti custom axle
So the U.P.P.E.R. ships standard with the U-turn. Since the U.P. is a post-mount frame, it ships with a post-mount fork, the 3T Luteus II.
Toptube bag mount
For handy storage of your phone, camera, some tools or food, you can use the toptube bag mounts. It fits the standard toptube bags from for example Dark Speed Works and XLab as well as dedicated ruggedized bags from for example Revelate Designs.
SafePost™ Pilot hole
Seatposts usually indicate a minimum insertion dimension. That keeps the seatPOST safe, but it's also important that the seatTUBE is supported properly. The minimum insertion for that is indicated by the SafePost Pilot hole.
Bottom bracket
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.
So why did Open decide to offer the U.P.P.E.R. with flatmounts? Three reasons:
| 1. |
|
Shimano has decided to make the new DuraAce group only available for flat-mount. So to use their top group, you need a flat-mount frame. |
| 2. |
|
SRAM does offer all its brakes in flat-mount and post-mount versions, but the flat-mount calipers are lighter. |
| 3. |
|
We came up with the U-turn, a new fork that accepts flat-mount calipers without the need for that silly adapter. So that disadvantage is eliminated for OPEN. |
In conclusion, to use the lightest possible brakes from both Shimano and SRAM, you need their flat-mount brakes. And thanks to the U-turn fork, you can make those set-ups even lighter by removing the normally required adapter. A win-win.
Click here for Geometry Chart
Click here for Specifications
Incl. in box: Frame, fork, headset, seattube collar, front & rear thru-axle, 2 rear derailleur hangers, 1 removable front derailleur mount, cover bolts for front derailleur mount posts, 3 MultiStops (2x, 1x, Di2), chainstay cable exit stop, BB guide, cable sleeves, noise-reduction foam sleeves, bottle cage bolts, manual
