BMC Kaius – Innovations for 2023: With the Kaius, the Swiss company is introducing a gravel bike that is strongly based on racing bikes and thus offers an interesting alternative to the trail-heavy BMC Urs. Velomotion has all the information about the new BMC gravel bike - a detailed test will follow.
A new gravel bike from BMC: The Swiss team is providing their MTB-inspired Urs with a gravel racer that is much closer to a racing bike. With Kaius, a long top tube and a short head tube ensure a sporty, stretched posture. In terms of seat geometry, the off-road racer lies between the Roadmachine (endurance) and Teammachine (racing) racing bikes, with the long reach of the gravel bike being compensated for by a shorter stem. However, the stem is also angled at -15°, bringing the handlebar position down a notch. At 72° in the usual six sizes, the steering angle is steep for a gravel bike; a long wheelbase of up to 105 cm improves traction and driving stability. The chainstays are rather short at 420 mm, which should make the bike quite agile.
Aero frame with sporty geometry
The frame has typical aero features, which, in addition to the low rear stays, also include an over-wide down tube that is supposed to keep the water bottle out of the wind. The seat clamp is of course integrated, the D-shaped seat post probably flexes as comfortably as on the Urs, but is offset 15 mm backwards. It is interesting that the dropout and fork are closed on the right side so that the ends of the thru axles cannot be seen. Apart from two bottle holders and the typical gravel bike bag on the top tube, no accessories can be mounted - after all, BMC is about "pure performance and racing without limits" instead of "bike packing and discovery tours".
Room for 44 mm wide tires
The tire clearance, which is given as 44 mm, is ample; with the 40 tires of the complete bikes, the Kaius doesn't look particularly long-legged. This could be interesting for those who want to use the bike on the road with narrower tires. The low weight also speaks for this purpose: BMC specifies a mere 1.785 grams for the frame set with carbon post and cockpit. In addition, in contrast to the Urs Carbon, the new model is tailored to double drives, so that all options are open when it comes to gear ratios.
Three complete wheels from 5.499 euros
BMC is presenting the new gravel bike in three versions: as the Kaius 01 One with SRAM Red AXS XPLR 1×12, as the Kaius 01 Two with SRAM Force AXS Wide 2×12 and as the Kaius 01 Three with SRAM Rival AXS Wide 2×12. The top model for a whopping 11.499 euros comes with a one-piece carbon cockpit and "Zipp 303 Firecrest" wheelset, whose 40 mm deep hookless rims with an internal width of 25 mm are ideal for wide tubeless tires. The SRAM drive with a 42 chainring and 10-44 ring gear is definitely suitable for mountaineering. Zipp 8.499 S are installed on the Two for 303 euros with carbon handlebars and cable routing through the stem – also with hookless rims, but with a depth of 45 mm and an internal width of 23 mm they prefer slightly narrower tires. The translation - 43/30 front and 10-36 rear - offers a very large translation range; If you want to ride the Kaius as a road bike on the road, you can retrofit a narrower cassette. The same applies to the Kaius 01 Three with SRAM Rival AXS and identical gear ratio, whose CRD 400 wheel set with 40 mm carbon rims was already convincing on the BMC Urs. At 5.499 euros, the Three is perhaps the most interesting variant in terms of value for money.
Useful alternative to the BMC Urs
Is the Kaius a useful addition to BMC's Gravel range? Definitely, because while the Urs closes the gap to the MTB in the LT version with a suspension fork, the new model is strongly based on the racing bike. Its frame geometry suggests a character that differs only slightly from the endurance racer Roadmachine, which is limited to 33 mm tire width. The Kaius is much more versatile, but it also raises the question of whether BMC should sharpen the profile of the Urs by giving the softtail graveller 50 or more millimeters of tire clearance. Be that as it may: If you don't get used to the trend towards gravel touring bikes and just want to be fast on a wide variety of terrain, you might like the new BMC Kaius.
