Is suspension performance a bit of an obsession to you? The SD Components Dynamic Volume Chamber takes spring curve control to a new level.
The not-so-minor details
SD Components DVC
Next level suspension control.
Easy to install and use.
What is the SD Components DVC?
The SD Components DVC is an Australian designed and made piece of kit, designed to improve the performance of your fork by giving you more control over the spring curve. At present, it’ll fit RockShox Pike, Lyrik, BoXXer and 2018 Revelation forks, along with the FOX 36 too.
It replaces the token/spacer system found in the forks listed above with a sealed, secondary air chamber, the pressure of which can be adjusted externally with a shock pump.
Fitting it is as simple as unthreading the old top cap, and threading in the DVC using the supplied laser-cut stainless steel tool. You adjust the main air spring via the valve number 1, while valve number 2 controls the progressivity.
What’s the idea here?
You’re likely familiar with the token or spacer system found in most new RockShox and FOX forks, where adding or removing spacers changes the fork’s air spring volume and therefore its progressiveness. The DVC takes this to another level, allowing you to make precise tweaks to the spring curve.
The DVC isn’t just about providing ease of adjustment – it provides more flexibility over the fork’s performance, allowing greater independent control over the beginning and end-stroke.
The pressure in the main air chamber dictates the fork’s sag and the performance for the first half of the stroke, the pressure in the second chamber controls the level of mid-stroke support and the bottom-out resistance. Fine tuning the pressures of the two chambers allows you to really alter the fork’s feel.
Why is it superior to a spacer system?
With a spacer system, you’re physically changing the volume of the main air spring, and as such any spacer changes, therefore, do necessarily have an impact on the fork’s initial bump performance. It’s a fairly rudimentary system really.
With the DVC, the volume of the main air spring is not impacted, no matter what pressure you have in the second air chamber. The second chamber only comes into play once an impact causes the pressure in the main air spring to exceed the pressure in the secondary chamber. As such, you’ve got genuinely independent control over these two aspects of the fork’s performance (beginning and end-stroke).
What did you fit it to?
We ran the DVC in a 170mm-travel RockShox Lyrik on the front of our Commencal Meta AM test bike. There was about a 20g weight penalty compared to the original Lyrik top cap with two Bottomless Tokens fitted.
One point worth noting is that the two valves are pretty prominent. On our bike, there were no clearance issues between the valves and the down tube, but on some bikes, with chunky, straight down tubes (like the new Treks) this could potentially be an issue.
How did it go?
Superb. Over the course of a few rides, we made fine adjustments, experimenting with small changes to the two chambers till we hit the sweet spot we liked. We wanted to maximise traction, so for a 65kg rider, we ended up with a main air spring pressure of only 43psi and with a touch over 80psi in the secondary chamber.
This netted a ridiculously smooth initial stroke, but with great support and bottom out resistance. With such a low pressure in the main air spring, the small bump performance was brilliant, giving a notably grippier front end in loose conditions.
If we’d wanted a stiffer mid-stroke, we could add a little pressure to the main air chamber. If a more linear feel was what we were after, dropping a few psi out of the second chamber would be the answer. We can see how useful this item would be for really heavy or very lightweight riders too, people who often struggle to get the setup they’re after.
So is it worth investing?
At $260, the DVC is not a cheap item, especially considering the stock RockShox/FOX volume spacer system works pretty effectively as it stands. The other consideration is that most people will find a fork setup that works for them and then rarely vary it.
On the other hand, there will be plenty of people out there who love to tweak, twiddle and fiddle, trying to get the absolute best out of their suspension, and the DVC definitely makes this process both easier and more precise. Enduro or downhill racers who are looking for the edge and who find themselves faced with changing conditions will certainly fall into this category.