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Gravel Gear

First ride review: BMC Kaius at Big Sugar Gravel

The new gravel race rig is aero and fast but more importantly, really fun to ride

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At this point in my tenure with VeloNews, I’ve participated in a lot of gravel events and ridden the gamut of distances.

While I love huge, expansive days on the bike — read, the LeadBoat Challenge or Unbound XL — I’ve also come to enjoy an all-out effort for 50 or 60 miles, like the Belgian Waffle Ride Wafers or SBT GRVL Red. The latter serve as particularly good motivation to go fast so I can get back to the finish line for reporting duties.

Read also: BMC expands gravel line with Kaius race bike

Before I knew just how awesome this bike was (Photo: Wil Matthews)

At Big Sugar Gravel last weekend, I did something uncharacteristic — I told people I wanted to win the Lil Sugar, the event’s 52-mile edition. It was partly in jest (because I am terrible at “racing” in the traditional sense) and partly serious (I got second last year).

Fortunately, I was also testing the new BMC Kaius, perhaps the best possible bike for the very windy occasion. And, if I don’t mention it now, my friend and former colleague Ben Delaney will accuse me of burying the lede (journalist speak for not getting to the point) — I won!

BMC Kaius One quick stats

The BMC Kaius, launched just six weeks ago, is the newest gravel offering from the Swiss brand, and Swiss Army Knife it is not. The bike shares more pedigree with the Teammachine SLR endurance road bike than the URS LT, BMC’s taller, slacker, more adventurey gravel offering.

According to the marketing-speak, the Kaius has one purpose: “to crush the competition in gravel races.”

The Zipp 303 Firecrest and Pirelli Cinturato made for a very fine pairing (Photo: Wil Matthews)

For Big Sugar, the folks at BMC hooked me up with a Kaius 01 One, the highest-end version of the three-bike Kaius quiver (retails for $11,999). The One comes decked out with a 12-speed SRAM Red AXS drivetrain, Zipp 3o3 Firecrest wheelset, and 40mm Pirelli Cinturato tires.

Its most attention-grabbing feature, however, is the all-new ICS Carbon Aero cockpit. And within that, the uncharacteristically narrow (for gravel) handlebars are the cockpit’s most visually arresting feature: measuring 360mm at the hoods, a 12.5 degree flare nudges them out to 420mm at the drops. More on this later.

All three versions of the Kaius have integrated stealth cable routing, however the Two and Three models forgo the aero cockpit for a normal two-piece bar and stem system.

Aero and integrated (Photo: Wil Matthews)

Every size Kaius, from 49 to 61, features the same 73 degree seat angle, 80mm bottom bracket drop, and 420mm chainstays. My size 51 measured 71 degrees at the head tube. The mainstay of the Kaius geo is its long front center (397mm reach, 530mm stack on my 51cm bike), optimized for both stability and quick handling.

The bike fits up to a 44mm tire, has recessed mounts on the top tube for an (aero) bento box, and its flexible D-shaped seatpost can be swapped out for a 27.2 mm dropper post. Other than that, it is frill-free.

The BMC Kaius at Big (Lil) Sugar

The gravel around northwest Arkansas is highly variable. It’s very different from the dirt I ride around Boulder and the Colorado mountains — sometimes it’s fast, smooth, and hardpacked, but more often it’s littered with small stones, semi-compacted ones, or what feels like a dump-truck load of them. Many roads are rarely driven, or maintained.

Basically, it’s unpredictable.

I was curious to see how the Kaius would do, given its purported mission, in such conditions.

The Kaius’ super aero cockpit was an initial prejudice. It came in very handy. (Photo: Wil Matthews)

When I first hopped on the bike pre-shakeout ride, the long reach was immediately apparent. However, with two quick adjustments — skootching the saddle forward and raising the hoods on the bars — I was in business. A two hour solo shakeout later, I was also very pleasantly surprised.

I prefer my daily driver gravel bike to have road-ish geometry, so I found the sporty position of the Kaius familiar and comfortable. I practically flew through town on pavement to get to the gravel. The bike’s need for speed is immediately apparent.

What was more notable, however, was that nothing in the feeling of the bike changed when I hit the loose chunky gravel that begins just outside of town. The 40mm tires and compliant frame absorbed all of the brain-rattling things out there — washboards, rocks, ruts — and the bike was super easy to steer and maneuver (short trail, tight rear end).

The Kaius’ workhorse characteristics are impressive considering it weighs next to nothing (1.785 kg) and is aero everything.

On race day, aero everything came in very handy. Windy and warm were the conditions on the day, and since my specialty is getting dropped at the start, I needed all the help I could get to spend three hours in the wind alone.

Thin seat stays accommodate 44mm tires, and 420mm chainstays keep things tight in back (Photo: Wil Matthews)

Was it the Aerocore bottle cages and the super aero handlebars that powered me to the top of the podium? We’ll never know. But I do know that I was amazed to look down at my Wahoo Elemnt every time I turned south into the wind to see that my speed didn’t change nearly as much as I thought it would.

Handling-wise, the bike performed like a dream, even at race pace. As much as I think this bike could be a n+1 for some people, it shouldn’t be mistaken for a road bike that fits wide tires. It’s a gravel bike that also goes fast on the road. I have ridden a road bike with 35mm tires during a gravel race, and it was fine until I was descending or going through some really techy stuff, at which point the bike my position on it became sketch and terrifying.

The Kaius was super stable on the descents, and even at speed into corners piled with gravel. The narrow bars didn’t bother me at all — I rode on the tops or hoods climbing and on undulating terrain, and easily made my way to the drops when descending or trying to get low on the flats.

I wasn’t able to take the Kaius on any singletrack or up any steep climbs, so I can’t comment on how it performs in either place. But, given how comfortable, fast, fun, and well, winning, it was to ride, I’d love to keep putting it to the test.

It must have been the bike (Photo: Tim Mohn)