XC racing on the Pivot LES 27.5+ bike
Our Sea Otter XC race rig, the revamped Pivot LES in its 27.5+ set-up (click to enlarge).
Anyone who’s raced the Sea Otter Classic cross-country has experienced the course’s litany of short but steep and loose climbs. Gradients are in the 15-18% range. Trail surface is akin to marbles on hardwood. Maintaining traction (and momentum) is difficult if not impossible — unless you happen to be racing a plus bike.
That was just one of the revelatory discoveries made during an experimental race day aboard the freshly revised Pivot LES carbon hardtail, which was launched just a few days prior at the mid-April event in Monterey, California.
The nuts and bolts of the new bike are straight forward. Pivot carried forward the carbon framed racer’s somewhat slack 69.5-degree headtube angle (though the size XL is actually 70 degrees), while slicing a reported 50 grams off the frame’s weight. They also added boost hub spacing, compatibility for Shimano Di2 electronic shifting, and most importantly, Pivot’s Swinger II rear dropout system, which allows for easy conversion from 29er to singlespeed or 27.5+. There’s roughly an inch of possible adjustment via dropout indexing. The shortest achievable chainstay length is a stubby 434mm.
Boost spacing front and rear means stiffer wheels and shorter chainstays (click to enlarge).
Being one who’s never embraced the appeal of one-gear bikes, I was far more interested in the addition of plus capability. And specifically what would it be like to race this bike in that configuration? Conventional wisdom says, bad idea. Instead of spinning on bulbous tires, the ideal XC competition rig (especially for fast rolling courses such as Sea Otter) is a hardtail or short travel full suspension 29er. At least that’s how the current thinking goes.
But abiding to conventional wisdom all the time is no fun, so I talked the Pivot crew into loaning me one of the new bikes set-up plus for my Cat. 2/45-47 men’s XC race. On tap was one lap of a roughly 19.2-mile course with 2600 feet of climbing. The track is mostly smooth and flowing, peppered with those aforementioned grinders, plus several longer, shallower ascents.
The bike’s spec included Shimano XTR drivetrain and brakes, a FOX 34 120mm fork, DT Swiss XM 551 alloy wheels with 40mm internal width, and Maxxis Ikon (rear) and Rekon (front) 27.5×2.8” tires. Gearing was a 34-tooth chainring paired with an 11-45 cassette thanks to OneUp’s 45t sprocket conversion kit that was necessary because Shimano’s wide range cassette wasn’t available at the time.
Even with this Maxxis Ikon 2.8″ tire there is still reasonable clearance (click to enlarge).
I didn’t have a scale handy, but figure this size XL tester came in around 23-24 pounds. It was race ready, no doubt, though I should mention that anyone interested in FOX’s new Step-Cast race-specific 100mm fork be warned. Its slim design does not play nice with plus tires, a fact we discovered during the conversion process.
Not surprisingly, the early portion of the race was not ideal. The Sea Otter course starts with about a ¼-mile drag race on the paved Laguna Seca Raceway track, a surface not particularly well suited to wide tires. I felt like I was working harder than those on 29ers shod with skinner rubber, which accounted for most of the riders in the 40-man field. That sluggishness, and my so-so fitness, meant the top 10 or so riders quickly disappeared into the horizon.
But as soon as we hit the dirt and started careening downhill on fire road, those plus tires revealed their better half. I never regained the front, but the wider contact patch pumped to about 17psi simply felt more comfortable — and safe — especially in the occasional rutted section where you had to jump from line to line to avoid getting closed out.
The revised frame has ports for just about any set-up, including Shimano Di2 (click to enlarge).
The plus tires also added a measure of suspension not existent on your standard hardtail. Occasionally the ride felt a little bouncy, but mostly the sensation was of sure-footed traction and stability at speed without losing any molars. The only thing missing was a dropper post, which is the first component swap I’d make if the bike were mine. (And yes, there are provisions for internal routing.)
Continue to page 2 for more of our first race review of the Pivot LES 27.5+ »
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