Bos Void, the air shock to big bikes

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The statement of the firm Toulouse with everything you need to know about this new shock…

1st DH air shock Bos

The Void is the first air shock produced by DH Bos. A technical option which might seem surprising to those familiar with the brand, since for DH, She has previously defended the quality of mechanical springs for shock absorbers as for the forks.

Provided, Bos is not his first attempt in the field of air shock. The Vip'R is already known for its use in Enduro or All Mountain, but long before that, there are already ten years, Bos had made a shock XC air for a major brand of bikes.

Bos had preferred not to work until today that steel springs for DH, without making it a principle unsurpassable. On the contrary, it has always been clearly stated that when the air spring would reach a level of performance at least equal to the mechanical spring, Bos come out his air shock.We must therefore believe that this moment has arrived !

Challenge : reproduce the behavior of a spring steel

Actually, the problem faced so far was the fact that a progressive air spring is : its stiffness increases with the taking of travel, contrary to a mechanical spring whose stiffness is constant. To properly manage the travel and damping via the hydraulic, this stiffness is constant capital. The objective, to move to the air spring was so clearly to achieve duplicate the stiffness of a spring steel, what is now the case.

The main advantage of air spring course, lies in weight gain, that will always remain a decisive factor for cycling. Between a Rare in Stoy 240 mm, with its spring and a Void, the difference is 356 g !

But the air spring offers other benefits…

Longer a question of racking her brain to see what spring should be selected based on its weight (or its evolution…). Casually is a fairly important step, especially in Bos, where the water very "fit" shocks requires to go through very precise spring stiffness (increments 25 lbs/inch ).

A real tire stop

Moreover, we saw that the air spring made in Bos gave a linear curve identical to that of a spring steel. This is, in any limit, the stiffness increases, thus functioning as a stop. Hence the abandonment of the hydraulic stop, now useless, but also the absence of buffer elastomer rod end. The anti tailgating is also managed by the air spring. With a significant difference compared to buffer elastomer : the transition is a gradual, where the stiffness increases abruptly when the buffer is biased. The result is an operation more "smooth" at the time of transition to the higher stiffness at the end of race.

Finally, this stiffness limit is adjustable, playing on the volume of the air chamber. A very simple operation to perform, requiring no tool, and therefore allows fine adjustment of the limit, via the stop pneumatic .

Five-way settings

We can therefore say that the Void offers five channels of adjustment (three-way hydraulic, two-way pneumatic), since the air spring is adjustable, two ways, where a spring steel is… interchangeable.

Provided, the air pressure in the cylinder remains stationary, and totally independent of the pressure in the chamber air. It is by no means an adjustment. The change would only affect the operation of the damper

The Void has a lot of laps in testing before being marketed, and it turns out that the air spring provides superior sensitivity to mechanical spring, particularly early in the race : where a trigger slightly lower, and of course the end of the race through the progressivity of the stop pneumatic. This combined with the manufacturing quality of BOS, which significantly reduces the friction, hydraulics is much less disturbed by mechanical interference with a spring steel.

The Stoy RaRe was a reference. The Void rises another notch in performance and in performance.

The Void is a very comparable to the Stoy shock RaRe, which incorporates the main features :

• specific setting for each bike,
• three-way hydraulic adjustments,
• term aluminum,
• mounting kit bearings…

The only thing that differs, ultimately it is the spring, now provided via an air chamber.. And the corollary lack of hydraulic stop. The diameter of the air chamber is identical to that of a spring steel. The overall size is identical to the Stoy. It is available in three lengths : 222, 240 and 267 mm.

The valve is adjustable forwardly and rearwardly. It is positioned anywhere in rotation - except in front of the cylinder ! It will be easy to access any type of bike used.

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