U.P. stands for "Unbeaten Path" – and OPEN very deliberately named this model as such. The OPEN U.P. is designed to deliberately go where you may only have accidentally before. The clearance for wider, more aggressive tires, the auxiliary mounts for racks or extra water bottles, and the ride and geometry that are more forgiving than a traditional road bike all encourage you to push your boundaries like you never have before on a drop-bar bicycle.
The OPEN U.P. took years of development, because the mission was unprecedented: build a platform that could crush a high-paced Saturday century, but then explore dirt roads and single track on Sunday. For the former goal, the U.P. was designed to pedal and handle like a road bike when equipped with 28mm tires. For the latter, it can accept 650b wheels with tires up to 47mm wide without compromising its agility and efficiency. Of course, disc brakes bring it all down to a stop when necessary.
OPEN is a proudly small, Swiss based manufacturer, founded by Gerard Vroomen (former Cervelo founder and engineer) and Andy Kessler (former CEO of BMC). The OPEN U.P., however, wasn't simply engineered to be a road bike with larger tires, based on what they'd learned from developing some of the world's most successful road bikes. The U.P. was designed to meet a need neither of them saw met in the market: a fast, flexible, and fun do-it-all machine that was as versatile as their tastes.