Inside Line: New Orbea Oiz 27.5 and 29 race bikes

With a few exceptions, most bike companies seem to shy away from making true cross country race bikes, instead designing trail bikes that can be raced. The new Oiz from Basque bike-maker Orbea is decidedly not a trail bike. This is pro-level race machine, ready to decimate the competition when the ability to ride both up and down hill matters.

A group of international journalists were taken deep into the French Alps to learn about and ride the new Oiz. As an extra incentive, this media camp coincided with the UCI World Cup races in Meribel, and we were just a short gondola ride away from all the action including the downhill finals.

The previous Oiz, released in 2011 may have been one of the last 26-inch XC race bikes to hit the market. While it was rarely seen in the U.S. (I’ll admit to not even knowing it existed before this press camp) it was well liked by the 26-inch holdouts, and even saw some use in the pro women’s ranks with 27.5 wheels shoehorned into the frame. But with 26-inch wheels going the way if the dodo, and 29-inch wheels winning races everywhere, something new was needed.

Rather than pick a side in the wheel wars, Orbea went with both, utilizing what they call “Big Wheels Concept”. The Oiz comes in both 27.5 and 29-inch varieties. The smaller wheels can be had in small, medium, large, with the 29-inch in medium, large, and extra large. The idea here is for more rider choice, with all but the tallest and shortest riders getting to choose whatever option fits both body and riding style most appropriately.

One of things Orbea seemed to take very seriously in the design of these bikes is a low stack height for all sizes. Stack is the horizontal measurement from the bottom bracket to the top of headtube, and the lower the stack height, easier it is to get the handlebars low, something very important for getting a proper aggressive position on a race bike.

The geometry of the Oiz was kept very close to the Alma hardtail, so the very speedy women of the Orbea sponsored LUNA Chix race team would be able to keep position consistent across the two bikes. The new bikes were well received by the team riders, as at least one of the ladies raced the Meribel World Cup race a few days after getting the bike.

The previous Oiz frame had less travel and used a carbon fiber plate in place of a main pivot, but the new design uses a more traditional single pivot design with a swing link activating the shock. The carbon seat stays are engineered to flex, eliminating the need for a pivot near the rear axle. This design, when executed properly, saves weight and increases stiffness, both important things for a XC race bike.

One of the more interesting parts of the suspension design is the skinny steel rod that spans between the pivots of the carbon fiber swing link. While the link was stiff enough in to hold everything together, under stress testing the bridgeless seat stay would bow out under compression, eventually causing the link to fail. Instead of reverting to a more common (and heavier) CNC aluminum link, a spoke was modified to keep the seat stays from flaring out. This simple and effective fix only added a few grams to the overall weight of the frame, while allowing Orbea to offer its lifetime warranty.

The Oiz also uses internal cable routing, but instead of a full run of housing inside the frame, only the liner is inside the frame, saving up to a hundred grams over a full housing run. Little touches like this adds up to a frame weight of 1,650 grams in a size small.

I got a in solid ride on both the 29 and 27.5 models in size large. As an extra treat, the bikes were equipped with 2015 XTR, one of the first chances for media (or anyone outside a few pro racers) to ride the new stuff on real off road terrain.

The bikes all share a 70 degree head angle, 74 degree seat angle and 12.9 inch bottom bracket height. Chain stays are 425mm on the 27.5, 445 on the 29. Top tubes are not terribly long for people used to trail bikes and short stems, but both bikes fit me just right for a race bike with a 90mm stem, flat bar and 20mm of spacers. The 29er felt good with the stem in a negative position, halfway through the ride on the 27.5 I flipped the stem to positive rise to adjust for the shorter stack height. Racers looking for an aggressive position will have no issues getting sorted on these race bikes.

Our ride involved a few gondola and chairlift rides and miles of mixed trails. We rode long, smooth singletrack traverses, loose over hard bike park trails, in the woods roots and switchbacks, and even some pavement back into town. The riding was far from tame, and I wouldn’t have felt out of place on a 150mm trail bike on some of the terrain.

In both wheelsizes, the Oiz impressed me with its stiffness, efficient suspension and ability to handle being used outside its intended design criteria. The handlebar remote for the Fox CTD suspension is ideal for a race bike in my opinion, allowing for a plus tune in full open Descend mode, a solid platform for putting down the power in Trail, and an almost full lock out in Climb, for the final sprint to victory.

I did wish for more low speed compression in Descend mode to help prevent brake dive to keep the fork higher up in the travel when pointed down, something a little more air pressure could accomplish, at the price of a more harsh ride.

Between the two bikes, the 29er would be my choice, as it is more suited to the longer races I prefer, but if I was younger and more sprinty, the 27.5 would be pretty appealing.

The shorter wheelbase of the 27.5 was felt in the switchbacks, although I was able to get both around corners with now issues. The 27.5 is more playful, and took to the air with ease, but was also more squirrelly when touching down on less than ideal terrain. Both bikes showed impressive stiffness, something that a serious XC racers demands.

I was very impressed at how hard both bikes could be ridden, right out of the box, on unfamiliar trails, and can see these bike being an excellent choice for the serious XC racer on demanding courses, while still be light enough to compete with the hardtails on less demanding tracks.

There is a range of bikes, from the top of the line Oiz M-LTD at $10,999 to the entry level racer M50 at $3,399. All Oiz models use a full carbon frame. The higher-end models have the lighter OMR (Orbea Moncoque Race) frame, while less-expensive bikes have a heavier, but still very light, OMP (Orbea Moncoque Performance). All models will be ready for sale this fall.