Open Cycles
Open Cycles
Open Cycles
Open Cycles
Open Cycles
OPEN models: Classic U.P., U.P.P.E.R., New U.P. and One+ ~ Come into TrekHP to see these bikes!

OPEN Cycles 

U.P. (Unbeaten Path)

Bicycles that combine a road riding position with clearance for mountain bike tires. Get out of town on asphalt, hit the gravel roads or switch to singletrack. Your position gets you there fast; the big tires make you unstoppable. 

Every U.P. and U.P.P.E.R. shares the same shape, geometry, intended use and most importantly: tire clearance. They do differ in layup, weight, fork, disc brake mounts, thru-axles and colour.

Classic U.P.

Classic U.P.

The Classic U.P. with 3T Luteus II fork and post-mount disc brakes.

OPEN Cycles invites you to ride the unbeaten path on the extremely versatile OPEN U.P. Unbeaten Path gravel frameset.

Riders need for better brakes and bigger tires increasingly evident as they seek adventure on back roads. The first solution is disc brakes, the second is clearance for wider tires. OPEN Cycles provides both of these and more. This new brand has approached the design process from the ground up to offer something unique to the industry, a disc-equipped road bike that can be ridden with 650b knobbies or 700c cyclecross tires. Ride where the road ends, ride the unbeaten path, ride the OPEN U.P. Unbeaten Path Gravel Frameset, the world’s first gravel plus road bike.

New U.P.

New U.P

The New U.P. with OPEN U-Turn fork and flat-mount disc brakes.

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. We don't like how the bike industry keeps “inventing” new standards, so we always investigate if they are an improvement before we use them.

Post-mount brake calipers work very well, and the main argument for flat-mount is that it looks better while a significant drawback is that the front brake always requires an adapter for mounting, adding weight and reducing braking efficiency.

So why did we 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 or an adapter to fit post-mount brakes on 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.

New U.P.

Open U.P.P.E.R.


The superlight U.P.P.E.R. with OPEN U-turn fork and flat-mount disc brakes.

Ride on asphalt, hit the gravel, or shred the dirt on the OPEN U.P.P.E.R. Frameset. With fast geometry, lightness, and big tires, this bike is unstoppable.

Building upon its OPEN U.P. bike, Open Cycle has kept the same geometry and tire clearance of the U.P., but differed its carbon layup, fork, disc brake mounts, and thru-axles to create the all new OPEN U.P.P.E.R. Frameset. With its lighter weight, enhanced stiffness, and increased simplicity, the OPEN U.P.P.E.R. Frameset looks and rides like a road bike, but can also conquer the roughest dirt trails and gravel roads.

OPEN One Plus


Designed with the versatility to be ridden with two different wheel sizes, the Open One+ frameset isn't just an ultra-lightweight hardtail, but also versatile enough for most any trail.

And then the bonus: Boost gave us enough space for 29x2.4” tires and tons of mud clearance, perfect for the ever more demanding XC courses. And similar to what we did on the U.P. the ONE+ also provides space to put in a 27.5x3.0” tire! 


Lots of confusion in the mountain bike world nowadays, between three wheel sizes, several axle standards, Fat & Plus tires, Boost, etc.

Boost moves the chain outward by 3mm without changing the Q-factor (pedal stance) of the crank. It basically uses up the space created when high-end bikes stopped using triple cranks.

Also moving the cassette out 3mm plus another 3mm on the disc brake side means the rear wheel axle grows from 142 to 148mm. This improves the angles for the spokes to create a stronger, stiffer wheel. Great for big 29er wheels but really a good thing for every wheel size.

Bottomline: same pedal stance/Q-factor up front for good pedalling efficiency, wider spoke stance in the rear for stiffer, stronger wheel builds. If you want, you can also do the same trick in the front with a Boost front hub (110mm vs 100mm) but that’s optional.

Why do we add Boost to this frame? Because it adds stiffness to the build, because it works well with the wider rims that we prefer and because it creates more tire clearance between tire and chain. Aside from these advantages, there really aren’t any drawbacks now that all manufacturers have started making their components in Boost versions.

Open One+

Open Cycles


Classic U.P.New U.P. U.P.P.E.R.
Frameset Price (USD, excl. sales tax) 2,600 3,200 4,500
Frame-only weight size M, grams, ±3% 1,100 1,040 880
Fork-only weight, grams, ±3% 460 390 370
Sizes S/M/L/XL X X X
3T Luteus II fork X
OPEN U-turn fork X X
Colour: OPEN Orange X
Colour: OPEN Brown X
Colour: OPEN Green X
Colour: OPEN Blue X
Colour: Matte black X
Ready-to-paint finish X X X
BB386EVO pressfit 86x46mm BB shell X X X
Shimano road cranks X X X
SRAM GXP road cranks X X X
SRAM Force 1 BB30 cranks X X X
Flat rings for 1x set-ups recommended X X X
Max 1x flat ring size 50t 50t 50t
Max 1x SRAM ring size 46t 46t 46t
Max 2x ring size 50/36 50/36 50/36
Standard Syntace X-12 rear thru-axle X
Superlight Carbon-Ti X-12 rear thru axle X X
Standard 3T 15mm front thru axle X
Superlight Carbon-Ti 12mm front thru axle X X
Front disc post-mount 160/180mm X
Front disc flat-mount 160mm only X X
Rear disc post-mount 160mm only X
Rear disc flat-mount 140/160mm X X
MultiStop internal cables for 1x11, 2x11, Di2 X X X
Integrated headset IS42/28.6 | IS52/40 X X X
Seatpost diameter 27.2mm X X X
3rd bag/cage mount lower downtube X X X
TT bag mount 100mm front-post-to-headset-edge X X X

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