While all that can sound quite complicated, all that matters to most riders is how it performs on the trail.Īfter spending most of the previous two seasons on multiple non-DRCV Remedys ( they were equipped with an RP2 and a RP23), I certainly have enough experience on both types of dampers to properly compare the two. You can also see the sealed bearing upper shock mount that Trek uses to mount the DRCV damper, making things a touch smoother. DRCV shocks have all used a modified rebound circuit to deal with the shock's dual spring rate, but the new 2011 models have been tweaked to add more end stroke control while not effecting the small bump response. Getting deeper into things, the Boost Valve compression characteristics have been tuned with a Light Velocity Tune and 175 psi.
The plunger is spring loaded so that when the shock rebounds, it retracts and closes the airway once again, leaving the smaller air chamber pressurized to the same psi as before. In the early stages of the travel the shock is working solely with the main air spring, at the 50% point of the stroke the plunger comes in contact with the seal head and is pushed up, opening the airway between the two air chambers and effectively creating one large chamber. Hidden behind the Trek bike's EVO link is the plunger that opens and closes the airway between the two. This photo of a Fox Float DRCV shock cutaway clearly shows the larger air chamber below (with the damping rod running vertically in the middle of it) and the smaller secondary air chamber located above. Keep in mind that changes to the air pressure, which acts as your spring, may necessitate changes to rebound settings. Once the spring rate is in the ball park, you can adjust your rebound setting accordingly.
#FOX FLOAT RP23 DRCV PRO#
As with any shock that uses a pedal assist, be sure to have the Pro Pedal fully open while going through the setup steps. With the recommended pressure in the shock I was sitting into 25% of the travel, a bit less than I thought I would eventually end up with, but a good place to start. Anytime you make a pressure adjustment you need to be sure to repeat these steps, not doing so will hinder setup and could result in a funky ride. The first pressure will read lower than the second pressure and it is the second pressure that correlates to the initial pressure you put in. Just make sure you screw it on fully and not stop at the first reading. This is due to the two Schrader valve system that connects the different chambers to facilitate set up filling. If you look closely as your putting the pump on, you will see two pressure readings as you screw it on to re-check pressure. If you don’t have enough sag, you’ll need to take pressure out and vise versa if you have too much sag. Once this is done you’ll need to check sag with the nifty clip on sag meter that tells you what percentage of the travel you're sitting in. What you are doing is pressurizing the smaller secondary air chamber and you need to push the bike far enough into its travel so the plunger is activated and opens the airway between the two chambers. Now comes the additional step required with the DRCV shock: it is very important for you to push the bike into 50% of its travel at this point in the setup. I weigh in at 170 lbs and so I pumped until the gauge read 180 psi. You'll want to start with about 10 psi more than your body weight. The DRCV equipped Remedy that I've been putting time on came with a card that gave me a guideline as to where to start with air pressure for the spring rate, but if you don't have it handy it's also listed on the Trek website. Setting up the DRCV shock is similar to any other air shock, but an extra step is required during the process that you wouldn't have to do with a standard unit.
The goal with this technology is to be able to have your cake and eat it as well, meaning to have a lively but firm spring to push against that is provided by the main chamber, but benefit from the secondary chamber's ability to add a more linear and forgiving end to the stroke.
The plunger is referred to as the control valve, or the "CV" in DRCV. Connecting the two chambers is a plunger, or valve, that opens the airway between the two at a predetermined point in the travel. The two different air chambers provide two different rates depending on where the shock is at in its stroke. The "DR" stands for Dual Rate, and is as simple as that. The extra length at the top houses the smaller, secondary air spring chamber, which is partly where the DRCV name is derived from. Another look though and it becomes obvious that there is certainly something very different going on here. If you only had a quick glimpse at the Fox Float DRCV shock you may not notice the damper's extra length that is positioned above the upper mounting point.