Editor's Note: This article is part of the Mtbr Ultimate Guide to winter mountain biking, fat bikes, gear, apparel, lights and trainers. We are taking a deep dive into all manner of cold weather mountain bike gear, with round-ups and reviews of fat bikes, tires, wheels, apparel, trainers and more. To see all the articles, head over to our Winter Guide Hub Page.

Lowdown: Pivot LES Fat

Depending on what part of the country you live in, buying a fat bike to ride away winter doldrums can be a wise purchase. But for some folks, fat bikes serve too narrow a niche of usefulness to justify the financial outlay - especially when that bike may only collect dust in the summertime.

Enter the carbon fiber Pivot LES Fat, quite possibly the most versatile fat bike (or even hardtail) on the market today. Thanks to its ability to run virtually any wheel size and tire width, the LES Fat can accommodate 26" fat bike tires up to 5" wide, and 27.5+ and 29+ wheels. And thanks to its innovative Swinger dropout system, the LES Fat can also be run as a singlespeed.

Indeed, if there were ever a fat bike that appeals to the person having a hard time justifying the expense, the impressively versatile Pivot LES Fat might be that bike. It can be used for touring, trail riding, and even mellow cross-country racing.

Frame: Internally molded carbon fiberBars: Race Face RIDE Riser 740mm
Cranks: e*thirteen 30t Stem and Seatpost: Pivot Phoenix Alloy
Sizes: S, M, LWheels: Sun/Ringle Mulefut 80mm w/Salsa Hubs
Headtube angle: 69 degreesTires: Maxxis Mammoth 26x4"
Wheelbase: 42.99" (S), 44.04 (M), 44.93 (L)Axle spacing: 150x15mm front, 197x12mm rear
Chainstay length: 437mmWeight: 27.5 pounds (size large)
Drivetrain: SRAM X01/GX1 1x11 10-42Price: $4,699 as tested ($2,599 frame/fork)
Brakes: SRAM Guide RRating:
4.5 Flamin' Chili Peppers
4.5 Chilis-out-of-5
Fork: Tapered carbon fiber w/ composite steering tube
Stat Box


  • Exceptional versatility
  • Performance muted with fat bike wheels/tires
  • Outstanding fit and finish
  • Allen key required for wheel removal
  • Capable and nimble chassis
  • Expensive
  • Massive downtube for excellent power transfer and steering sharpness
  • 150x12/197x12 axle spacing looks wrong with 27.5+ wheels
  • Downtube also serves as effective mud guard
  • Three bottle cage mounts, rack mounts
  • Internal cable routing (dropper too)
  • Absolutely rips with 27.5+ wheels
  • 26x5", 27.5+ and 29+ compatibility
  • Swinger dropouts allows singlespeed set-up
  • Compatible with RockShox Bluto

Review: Pivot LES Fat

Tempe, Arizona-based Pivot is riding high these days, making some of the most capable and versatile bikes in the industry. The Pivot LES Fat is the latest example. Like every carbon fiber Pivot, the true beauty of the LES Fat is in the design details. Highlight include a beautifully executed cable port system with removable ports for easy full-length internal cable routing including dropper post, a full carbon fiber tapered fork with 150mm wide dropout, a rubber chainstay guard with carbon fiber weave finish to silence chain slap, an adjustable Swinger dropout system that can change the bike's wheelbase to accommodate a variety of wheel size options, the capability to run three water bottle cages, and even provisions to run front and rear racks for multi-day adventures. Indeed, the LES Fat is designed to be as capable as it is light, responsive, and quick.

Continue to page 2 for more of our Pivot LES Fat fat bike review »

LES Fat is compatible with numerous wheel sizes.

LES Fat is compatible with numerous wheel sizes (click to enlarge).​

Another endearing aspect of the LES Fat is its gargantuan downtube and bottom bracket shell that seamlessly come together into one massive hunk of carbon fiber. There are no shims or spindle extensions to gain the full bottom bracket width needed for 5" fat bike tires, the full-width LES Fat features a 132mm wide press-fit bottom bracket with a narrow Q-factor design when built with the E-Thirteen cranks, co-designed specifically for the LES Fat. This design gives the LES Fat a Q-factor of 210mm. The LES Fat can also run either 1x or 2x drivetrains and is compatible with RockShox's Bluto suspension fork.

Massive downtube provides sharp handling, great power transfer and an effective mud guard.

The massive downtube delivers sharp handling, great power transfer, and it's an effective mud guard (click to enlarge).​

Depending on which wheel size option you chose, Pivot includes a zero-stack and 18mm height headset cup to help balance the bike's geometry. To ensure plenty of mud clearance even with 5" tires, the LES Fat features 197mm rear hub spacing.

Pivot LES Fat

Internal cable routing is clean. And the bike does great in the snow. (click to enlarge).

Ride Impressions

Pivot sent Mtbr two sets of wheels to try on the LES Fat, 26" fat bike wheels and 27.5+ hoops. I started by taking the LES Fat on a 20-mile snow ride through Dog Valley, 20 miles northwest of Reno, Nevada. Honestly, because of the snow and the size of the tires, the ride qualities of the LES Fat were rather muted, like putting a set of under inflated mud terrain tires on a Porsche. I couldn't really get a sense of how the LES Fat handled because I was too busy slogging through snow at 3mph.

However, the one benefit of the LES Fat I did appreciate was its relatively light 27.5- pound weight. I would have been far more miserable on a aluminum fat bike weighing 5 to 10 pounds more. So as far as a fat bike goes, the LES Fat with 4" tires rides more like a slightly obese bike, which in my mind is a compliment.

Putting 27.5+ wheels on drops 2 pounds of rotating mass.

Putting 27.5+ wheels on the Les Fat drops two pounds of rotating weight (click to enlarge).​

To get a better sense of how the LES Fat rides in more traditional trail conditions, I swapped on the set of 27.5+ wheels and headed to Auburn, California, for a 25-mile loop with 4,000 feet of climbing on Foresthill Divide Trail. I had a riding buddy with me who piloted a super light XC hardtail to see if I could keep up. Surprisingly, not only did I keep up on the LES Fat, but I also managed to pull away from him in certain areas.

Pivot LES Fat

LES Fat was a blast on Culvert Trail (click to enlarge).

Running the plus-size wheels on the LES Fat really woke the bike up so I could get a sense of its inherent handling characteristics, plus it dropped two pounds of rotating weight with the narrower tires. It's fast, responsive, nimble and quite plush for a rigid bike thanks to its thinner seatstays that are optimized for vertical compliance. And thanks to the rather slack 69-degree headtube angle, the LES Fat was eager to wheelie and manual without being slow-witted when cornering. And with the 3" Maxxis Chronicle tires, the LES Fat had an ungodly amount of traction, especially in muddy corners.

The ride was so comfortable I quickly started pushing downhill speed until I hit the bike's limitations, or should I say my own limitations. Flashbacks of pre-suspension days came rushing to my brain, as my eyeballs rattled uncontrollably like marbles in a tin can. Even with the bigger tires and a full carbon chassis, just like any traditional rigid bike, the LES Fat still has limitations. And once the slight pogo effect of the larger volume tires is set in motion, a speed check is required to quell it.

Without a doubt, what makes the LES Fat perform with the big yet powerful grace of an NFL defensive lineman is the bike's massive downtube. There is absolutely no vagueness when steering into a corner, and power transfer to the rear wheel is immediate. The LES Fat could easily be used as a cross-country race bike. The chassis is that good.

Because the trails were a little muddy in spots the day we rode Auburn, an added benefit of the massive downtube proved to be quite an effective mud guard, helping catch the majority of the muck coming off the front tire. And for those who regularly ride in muddy conditions, the LES Fat has massive amounts of tire clearance with the 27.5+ wheels, preventing mud from caking up between the frame and tires.

Continue to page 3 for more of our Pivot LES Fat fat bike review »

Cornering is quick and predictable with 27.5+ wheel.

Cornering is quick and predictable with 27.5+ wheels (click to enlarge).​

As an added note, this was the first time I've ridden 27.5+ wheels. I've got six months of saddle time on a bike with 29+ wheels, and if I were going to get the LES Fat, I'd go for the 29+ over 27.5+. After riding both sizes, I feel like the 29+ wheels have significantly more rolling speed, and their bigger outer diameter helps smooth out trail chatter while making it a more capable climber in super rocky terrain. As good as the LES Fat is with 27.5+ wheels, I can only imagine how much better it would be with 29+ wheels.

My only hesitation in wanting to buy this bike is the 150mm front axle spacing and the 197mm rear axle spacing. When running plus size tires, it just looks aesthetically wrong. However, because this is meant to be a versatile hardtail capable of running 5" wide tires, it's a necessary evil.

LES Fat is quick and nimble with 27.5+ wheels.

LES Fat is quick and nimble with 27.5+ wheels (click to enlarge).​

Bottom Line

The LES Fat can be summed up with three letters - F. U. N. This bike is a grin producer that's definitely the most capable rigid bike I've ever ridden. I'm sure there will be people who choke up when they see the list price of $4,699 - and that's without the Bluto. But remember that the LES Fat is multiple bikes wrapped into one. You can ride it in the snow, you can ride it in the mud, you can race it, and you can do multi-day backcountry adventures. Depending on your needs, the extra money spent on a LES Fat and its versatility might be a better investment than spending half the money on a heavier, slower dedicated fat bike that will likely collect dust half the year.

For more information visit www.pivotcycles.com.