If you reduce or eliminate surprises and unpredictable variables in downhill racing, control automatically improves - and with it, speed. RockShox follows precisely this principle: together with professional athletes from the Downhill World Cup, the Americans have optimised their Boxxer double crown fork down to the smallest detail in recent years. The focus has been on reducing friction losses in the chassis in order to keep shocks and vibrations away from the rider more effectively. A super-linear spring characteristic for maximum predictable response behaviour was also at the top of the new Boxxer's specifications. And to ensure that suspension and damping harmonise perfectly, RockShox has also added a new damping cartridge to its new Linear XL air spring: the Charger 3.2.
The RockShox Boxxer in the fact check
| Damping | Charger 3.2 RC2 (with ButterCups on the Ultimate model) |
| Spring | LinearXL (with ButterCups on the Ultimate model) |
| Spring travel | 180 mm, 190 mm, 200 mm |
| Fork offset | 44 mm (27.5"), 48 mm (27.5"), 48 mm (29"), 52 mm (29") |
| Wheel size | 27,5", 29" |
| Models and prices | Ultimate and Select model for 2180 euros and 1635 euros RRP respectively. |
LinearXL air spring: pure predictability!
The new LinearXL air spring from RockShox pursues a clear goal: a 100 % linear spring characteristic. This means that the force required to compress the spring increases constantly over the entire spring travel. This creates a predictable, even ride feel - similar to a steel spring. At the beginning, the spring is extremely sensitive, in the middle it offers counter support, and towards the end a puncture protection protects against hard impacts.
RockShox also explains that the new air spring design is primarily intended to influence the riding position and the negative suspension travel of the bike. Although volume spacers can still be used for additional progression, they eliminate the linear spring characteristic. RockShox therefore recommends fine-tuning the response behaviour exclusively via the damping unit.
AirAnnex: More air volume, fewer surprises
With the new Boxxer, RockShox has finally revealed the secret of the black cover at the bottom of the left fork tube. The first prototype forks with this feature appeared in the Enduro and Downhill World Cup last year. Now it is clear: it is the so-called AirAnnex additional air chamber.
The AirAnnex increases the air volume inside the left dip tube and reduces the progression in the casting when compressing the air spring. This supports the linear response behaviour of the new LinearXL air spring. At the same time, the additional chamber also ensures that the left and right dip tubes have the same air volume. The damping unit on the right-hand side is smaller and takes up significantly less space inside the fork than the air spring. The additional volume of the AirAnnex therefore guarantees that both sides work with the same air volume despite the larger air cartridge.
The Charger 3.2 damping cartridge
In order to harmonise the damping of the new Boxxer with the linear characteristic curve of the new air spring, the compression damping has been significantly increased compared to the Charger 3.1. This is the only way to keep the fork stable in its travel and provide sufficient support for hard landings or fast sequences of hits. Also new on the Charger 3.2: numbered high and low-speed compression adjusters. The simplified display is intended to make tuning easier, especially for less experienced riders. The basic setting starts at "0". From there, the damping can be gradually increased (+) or reduced (-).
Constant plain bearing lubrication: ButterWagonTech
ButterWagonTech - this is how RockShox describes the numerous recesses on the stanchions of the Boxxer. They absorb oil from the dip tubes with every spring movement, transport it towards the bearings and release it there again. This continuous oil transfer ensures permanent lubrication of the plain bearings. This reduces friction in the system, improves the response behaviour and increases the durability of the plain bearings.
ButterCups against vibrations
The ButterCups are one of the technologies of the new Boxxer that we already know from other RockShox forks. These are elastomers at the lower end of the air spring and the damping unit. These rubber buffers allow both units to float in the lower section of the chassis. This design reduces high-frequency vibrations. This takes the strain off hands and forearms and can delay fatigue on long descents. However, this feature is only used in the more expensive Ultimate version.
Fine tuning for the Vivid Coil steel spring damper
To complete its downhill suspension, RockShox has also refreshed its Vivid Coil coil shock. With a shorter but wider reservoir, the shock should now be compatible with even more frame platforms. In addition, the newcomer also has numbered compression adjusters to match the Boxxer. The developers have also tweaked the RC2T damping so that it harmonises perfectly with the new air spring and the Charger 3.2 damping cartridge of the Boxxer.
Conclusion from Max Fuchs
The new Boxxer is full of well thought-out technologies. Lower friction losses in the chassis, the super-linear air spring and proven elements such as the ButterCups should ensure more stable, comfortable and controlled handling than the previous model. However, it remains to be seen how the new features prove themselves in practice and how reliably they work in the long term. The new features on the Vivid Coil are comparatively unspectacular. Above all, they should improve handling and make operation easier without radically changing the riding experience.
Max Fuchs
Editor
