With optimised efficiency, a more versatile range of use and consistent lightweight construction, the new BMC Twostroke 01 aims to be a state-of-the-art multi-tool for XC races and epic adventures.
Renaissance of the hardtail in a full-suspension world
In recent years, it seemed as if the full-suspension mountain bike would finally oust the classic hardtail from the world's race tracks. But BMC wants to prove this wrong with the second generation of the Twostroke 01. Developed in the renowned Impec Lab in Grenchen, Switzerland, this bike is not just a relic of days gone by, but a highly specialised answer to the increasingly technical cross-country courses.
The philosophy behind the new model is "Every Watt. Every Win." According to the Swiss company, the aim is not just to build a lightweight bike, but a system that converts every watt invested by the rider into propulsion without loss. BMC claims to have recognised that the modern hardtail rider today has a broader application profile: He starts at the local XC race, sets off on extravagant bikepacking adventures or even uses the bike for demanding gravel missions.
New geometry: Speed by design
The centrepiece of the Twostroke 01 is its significantly modified geometry, which is based on the philosophy of the BMC Fourstroke (the full-suspension XC flagship). BMC has lengthened the reach by around 10 mm across all frame sizes. In combination with a steering angle of 66.5 degrees, which is very slack by cross-country standards, this gives the bike a smoothness and stability on technical descents that is otherwise only known from trail bikes, say the Swiss.
At the same time, the standover height has been reduced to increase agility off-road. A shorter head tube prevents excessive stack, even when modern suspension forks with 110 mm or 120 mm travel are fitted. The seat angle has been increased slightly (76 degrees) to ensure a central and efficient position on steep climbs. According to the manufacturer, the result is a bike that performs like a mountain goat on the climbs and conveys the confidence of a downhill specialist on the descents.
The geometry in detail
To visualise the significant changes, it's worth taking a look at the exact data in the geometry chart. BMC offers the Twostroke 01 in four sizes (S to XL), whereby the chainstay length has been kept constant at a compact 425 mm for maximum agility in all sizes. There are significant changes to almost all the relevant geometry dimensions. The reach and stack have been increased by 15 and 13 mm respectively, while the wheelbase has grown by 33 mm. The steering angle was slackened by 0.5 degrees and the seat angle steepened by 1 degree.
The geometry data of the BMC Twostroke 01
| Frame size | S | M | L | XL |
| Height (cm) | <172 | 170-182 | 180-192 | >190 |
| Seat tube (mm) | 400 | 440 | 480 | 520 |
| Horizontal top tube (mm) | 596 | 621 | 647 | 674 |
| Reach (mm) | 430 | 455 | 480 | 505 |
| Stack (mm) | 603 | 612 | 621 | 635 |
| Head tube angle (°) | 66.5 | 66.5 | 66.5 | 66.5 |
| Seat tube angle (°) | 76 | 76 | 76 | 76 |
| Chainstays (mm) | 425 | 425 | 425 | 425 |
| Bottom bracket drop (mm) | 63 | 63 | 63 | 63 |
| Fork caster (mm) | 108 | 108 | 108 | 108 |
| Wheelbase (mm) | 1139 | 1166 | 1194 | 1224 |
Weight: fighting for every gram
In professional racing, every gram counts. The new Twostroke 01 frame weighs exactly 920 grams in size M including all hardware (thru axle, derailleur hanger, clamps). Without paintwork and add-on parts, the weight even drops to approx. 810 grams. These are very good values
If you put this weight in relation to the three lightest production race hardtails on the current market, it becomes clear that the BMC is definitely competitive:
- Specialised S-Works Epic HT: At approx. 790 grams (painted frame), it remains the benchmark in extreme lightweight construction.
- Orbea Alma OMX: At around 830 grams, it is just ahead of the BMC, but focusses on a somewhat more classic geometry.
- Canyon Exceed CFR: At approx. 835 grams, it offers similar values to the BMC.
However, BMC did not want to be misled by the competition for the lightest frame in the world, according to the manufacturer in favour of system integration and stability. The Swiss engineers argue that the time gained through the progressive geometry and the increased comfort on the descent is more valuable than a saving of a few grams.
Comfort equals speed
A hardtail is traditionally a hard machine. But BMC uses the "Tuned Compliance Concept" (TCC) to incorporate vertical flex into the carbon structure. The D-Shape carbon seatpost in particular contributes to this with its flattened profile without sacrificing lateral stiffness. This is easy on the rider's muscles over long distances and ensures better traction of the rear wheel on uneven surfaces. If you still prefer a dropper seatpost, you can easily retrofit 27.2 mm dropper posts thanks to a special reduction sleeve.
Technical refinements
In addition to performance, BMC has also focussed on ease of maintenance and versatility. The Twostroke 01 is optimised for modern 110 mm suspension forks, but also supports setups from 100 to 120 mm. The tyre clearance is generous at up to 2.4 inches on 30 mm wide rims, which allows the use of modern XC tyres with plenty of volume.
Further technical details:
- UDH standard: Compatible with the latest SRAM Eagle Transmission drivetrains
- BSA 73 mm bottom bracket: A bolted bottom bracket ensures peace of mind and easy maintenance
- Internal Cable Routing (ICR): The cables run protected inside the frame, which ensures a clean look
- Chainring compatibility: Supports sizes from 26 to 38 teeth
From XC race to gravel monster
The versatility of the Twostroke 01 is demonstrated by its approval for bikepacking bags inside and around the frame triangle. The option of a gravel conversion is also interesting. However, BMC points out that the reach of the frame is 60 to 75 mm longer than that of a standard gravel bike. The conversion to a drop bar is technically possible, but requires a sophisticated setup due to the length of the frame. It remains an XC bike at heart, but one that is ready to push the boundaries of its genre.
The Twostroke 01 One is equipped with SRAM GX AXS (1x12). Price: 5,499 EUR
The BIKE verdict on the BMC Twostroke 01 One
With the second generation of the Twostroke 01, BMC has taken an innovative step in two respects. The consistent adaptation of the geometry of the full-suspension Fourstroke should make it even more competitive in racing use. Increased comfort, greater tyre clearance and approval for bikepacking bags extend the range of use towards gravel adventurers.
Josh Welz
Editor-in-Chief
