Pivot

LES 29 Carbon Mountain Bike Frame - 2019

Full squish may be a lot of fun, but sometimes picking your lines meticulously through chunky rocks, or powering up singletrack on a hard tail is just more rewarding. Pivot's LES has been a bike of choice for many of us when seeking XC endeavors, and the newest iteration of the LES 29 is no different. The Pivot LES 29 has a lightweight body with new-school XC geometry that begs to speed over countless miles of singletrack when built up 29er, and its 27.5+ capabilities let it blur the lines when paired with a bigger fork, bringing out smiles through the chunder and swooping banked turns. It shares the same geometry as the 2017 model, which saw welcome updates from previous model years thanks to tweaked geometry, and updated carbon the shaved weight off for a racier feeling bike that's ready for the trail.

All told, the latest model is a claimed 50g lighter than the previous LES. This weight loss is largely attributed to updated carbon fiber construction, with hollow core construction featuring an internal-mandrel process, but the new Swinger II dropout system also had something to do with the weight savings, as it's lighter than the original Swinger. Lower weight may sometimes pair its self with less efficiency, however the Swinger II interface is actually stiffer, which is most likely caused by the stretched out rear hub that was updated to Boost 148mm rear axle spacing. Like its heavier predecessor, the latest LES is built with the ultimate goal of finding the balance of comfort and efficiency — the holy grail of trail-tuning a frame

While the frame's carbon construction is notable, the key difference between LES 29 generations is the Swinger II dropout system. As opposed to the pervious LES 29er, who's Swinger design was a reach to keep pure 29ers relevant in a world that's heavily coated with 27.5 wheels, the Swinger II design incorporates mid-sized wheels by allowing the frame to swap between 29 and 27.5+ wheelsets. It also still allows you to swap to a singlespeed conversion, addressing common issues of brake interface and chain tension. The design swings around a pivot that's located in the front of the upper-post-mount of the brake to maintain chain tension with negligible effects on the geometry. Since the bike can also be run as a one-by or double, and includes porting for electronic shifting, the new LES 29 is compatible with pretty much every major innovation that we've seen display value to a drivetrain.

The frame is laid-up with high-modulus carbon fiber and a Pivot's own hollow core, internal molding process. Since the material is compacted to a rigid internal form, the shape and thickness of the walls is precisely controlled. This eliminates the finishing steps that other manufacturers' frames require, which involve adding resin and reinforcement to address imperfections. Adding material means adding weight, and the presence of structural imperfections make for a less sound frame whose stiffness and trail-tune can very radically from what the engineers drew up in their design software. Pivot's construction process eliminates all these variables by leaving nothing to chance and ensuring that every frame rolling off the mold rides the way it's supposed to.

And that's a good thing, because this frame is designed to leave scorch marks across gopher holes on XC courses. The huge over-sized box section down tube and bottom bracket juncture is basically a capacious maw that feeds power efficiently into the rear wheel. The tapered head tube also helps in this regard, but it's most welcome for keeping tracking on point through tricky sections of trail furniture. The stays are shaped with the same hunger as the down tube, devouring trail chatter before it hits the seatpost while maintaining the drive spine's efficiency.