The BMC Kaius 01 ONE combines classic aero concepts and a narrow cockpit for an aero system that prioritises the position of the rider. At 7.72 kg, the Kaius is one of the lightest bikes in the test field, but it is also one of the most expensive, priced at € 11,499. Has it got what it takes to outpace the competition?
This bike was reviewed as part of our 2023 gravel race bike shootout. You’ll find a comprehensive group test and test field overview here: Which is the best gravel race bike of 2023? 9 gravel race bikes in review
BMC are a well-known Swiss bicycle brand that represent racing, Swiss design… and Swiss prices. We tested the flagship Kaius 01 ONE model, equipped with components that leave nothing to be desired. The Kaius is an all-new addition to the BMC portfolio, supplementing their gravel range with a more race-oriented option alongside the more trail-oriented URS. With its low weight and aerodynamic optimisation, the Kaius is an all-rounder among race bikes, though it is uncompromisingly optimised for speed, nonetheless, resulting in an extremely stiff and lightweight package. BMC’s approach to aero takes things one step further: Besides saving weight, a narrow handlebar results in a more aerodynamic position for the rider. BMC opted against deep tube profiles to save weight and increase compliance, which promises to offer the perfect compromise for a variety of races and tracks. Read on to find out whether the concept delivers.
The BMC Kaius 01 ONE – A gravel newcomer with street cred
The BMC Kaius 01 ONE is based on the BMC Teammachine, the all-round road bike from BMC, a race weapon designed for minimal weight and aerodynamic optimisation. Along with adapted geometry, the biggest difference on the Kaius is in the carbon lay-up. Thus, its frame weighs 90 g more than the frame of the Teammachine road bike. Added to that are a host of beautiful details like the closed dropouts and perfectly integrated components. The cockpit and frame look like they’re made from one piece, not least because of the matching colour. The covered bolts on the stem keep it all looking neat. This is rounded off by the short bar tape, though it makes some positions on the tops a little less comfortable.
BMC Kaius 01 ONE
Seatpost Kaius 01 Premium Carbon D-Shaped Seatpost
Brakes SRAM Red eTap AXS HRD 160 mm
Drivetrain SRAM Red eTap AXS 1x12
Stem ICS Carbon Aero 70 mm
Handlebar ICS Carbon Aero 420 mm
Wheelset Zipp 303 Firecrest
Tires Pirelli Cinturato TM Gravel H 700 x 40c
Size 47 51 54 56 58 61
Weight 7,72 kg
colour matched one-piece cockpit
integrated bottle cages
The frame design is super clean and modern. Unlike Ridley, Factor and others, it doesn’t have your typical oversized, aerodynamic tube shapes – it’s not a bike that’s screaming “aero!” in your face, but it’s got some tricks up its sleeve, nevertheless. The narrow handlebar forces the rider into an aerodynamically optimised position, minimising the biggest drag factor. Combined with a classic D-shaped seat post, integrated bottle cages and skinny tubes, the result is a coherent concept with a focus on minimal wind resistance and weight. So, it remains a bike that is aerodynamically adapted, though without losing sight of its intended use and offering a certain degree of comfort – unlike the Factor. Weighing in at just 7.72 kg, the Kaius is also the second lightest bike on test after the Crux, though by a long margin, weighing 500 g more than the featherweight Specialized.
The BMC Kaius 01 ONE – Swiss neutrality or thoroughbred race bike?
Just as with the look and feel of the frame, a lot of attention has also been given to the details of the components: The bike comes equipped with the high-end SRAM RED AXS eTap groupset, though without a power metre, which is unfortunate considering the price. The tread pattern of the 40 mm Pirelli Cinturato™ Gravel H tires performs convincingly on fast, hard surfaces.
Thanks to the stiffness of the frame, the 2023 BMC Kaius 01 ONE is very good at sprints, it accelerates effortlessly and feels very sprightly, but it’s overly harsh for less fit riders. The handling is determined by the aggressive geometry and narrow handlebar, making it agile and responsive. It is a lot more agile than the Factor OSTRO Gravel with its marked straight-line stability. That said, the BMC doesn’t mind putting on blinkers either, galloping ahead with full force while happily keeping a straight line. Compared to the Specialized S-Works Crux, the handling feels more balanced and thus better suited to straight gravel roads.
Fast, hard, and sexy – The BMC will get your blood pumping and then kick your butt.
For riders with wide shoulders, the narrow handlebar can be a problem in slow technical sections with steep turns. In these instances, a wider handlebar, like that on the Crux, would be advantageous due to its increased precision, especially for gravel newbs. Nevertheless, the Kaius performs well on fast sections and technical terrain if you’ve got the skill and experience. If we had to classify it, we would say the BMC is a combination of the Specialized Crux and the Factor OSTRO Gravel. It is aerodynamically optimised, though without resorting to deep tube profiles, focusing on keeping the weight to a minimum, and offering a little more comfort than the Factor OSTRO Gravel.
BMC Kaius 01 ONE
|Seat tube||428 mm||452 mm||468 mm||493 mm||513 mm||533 mm|
|Top tube||546 mm||559 mm||569 mm||579 mm||592 mm||604 mm|
|Head tube||85 mm||106 mm||123 mm||144 mm||170 mm||196 mm|
|BB Drop||80 mm||80 mm||80 mm||80 mm||80 mm||80 mm|
|Reach||390 mm||397 mm||401 mm||405 mm||410 mm||414 mm|
|Stack||510 mm||530 mm||550 mm||570 mm||595 mm||620 mm|
Who is the BMC Kaius 01 ONE for?
The BMC Kaius 01 ONE provides a lot of speed and a minimum of comfort, making it a full-fledged gravel race bike. However, due to the aggressive geometry and the narrow handlebar, it isn’t a bike we’d recommend for beginners. For experts and athletes with experience, the Kaius 01 ONE is a fast gravel race bike that can be used to conquer most gravel races. And if you lose, you definitely can’t blame it on the bike. Due to the lack of comfort, the bike isn’t your best bet for ultra-distances and multi-day rides. For well-trained riders like our editor Simon, who was allowed to ride the bike before its official release, the lack of comfort isn’t a problem. It’s the ideal companion if you have a need for speed, even if you’re not racing, and it will turn heads despite the minimalist design.
Tuning tips: A power metre and longer bar tape for more comfort on the tops.
Conclusion on the BMC Kaius 01 ONE
Racing weapon and bone rattler are apt descriptions of the BMC Kaius 01 ONE. It looks like a fast, aerodynamic gravel bike, but it’s the stiff frame and narrow handlebar that make it a thoroughbred racer. The overall concept has been implemented consistently, optimised for racing both visually and technically. If the Swiss price tag doesn’t put you off, you will get a coherent bike with refined details, high-end components, and excellent climbing capabilities. Unfit riders are best advised to look for something a little more forgiving.
- attention to detail
- uncompromising race bike
- lack of compliance
- no power metre (given the high price)
You can find out more about at bmc.com
For an overview of the test fleet head to the group test: Which is the best gravel race bike of 2023? 9 gravel race bikes in review
All bikes in test: Argon 18 Dark Matter | Berria Belador Allroad 8 | BMC Kaius 01 ONE | Canyon Grail CF SLX 9 eTap | Factor OSTRO Gravel | Fara Cycling F/All-Road | Ridley Kanzo Fast | Specialized S-Works Crux | Trek Checkpoint SLR 9 eTap
No, it’s not about perfect race tracks, it’s about efficiency. Fast, fleet-footed and efficient – those who want to speed along high-speed passages need a defined and spritely bike that accelerates with ease and efficiency. Nevertheless, reliable components are important too. We interpret “Smooth tarmac” bikes as follows: Hard efforts at high speeds with a maximum efficient bike on a consistently well-paved road. Effort-joy ratio: 80:30 (not everything has to be 100%!)↩
… also known as bike riding. Broken-up roads in the hinterland, deadlocked gravel roads, loose surfaces – sometimes muddy, sometimes bone-dry. For this, it takes bikes with super all-round, handling and wearing qualities uphill and downhill. Effort-joy ratio: 50:50↩
If you want to use your bike almost every day, you usually do not need an extremely tuned racing machine. Solid components, which are able to cope with the rigours of continuous usage in any kind of weather, are part of the basic equipment. At the same time, the bike should have practicable details: integrated fenders/assembly options, luggage racks/attachment points and a light system or at least the option of installing bike lights. The position on the bike should be rather relaxed, the overall comfort high, so that the Afterwork Ride becomes a cure and not a curse. Effort-joy ratio: 30:70↩
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Words: Calvin Zajac Photos: Robin Schmitt, Jan Richter