Test: The Fox DPX2 and the DT Swiss R414 in comparison. Two different dampers that have one thing in common - both have a very linear characteristic curve, which should ensure very good response. The whole thing was tested in the Orange Stage 6, which is also known for a very linear characteristic. How will the two dampers fare in comparison?
Linear characteristic
The spring characteristic can be divided into three parts: the breakaway torque, the course of the spring deflection and the final progression. At best, the breakaway torque is barely perceptible, the middle part of the spring travel increases linearly - so that you don't rush through the spring travel - the final progression instead prevents noticeable bottoming out.
A linear characteristic curve ensures that the damper works evenly over the entire spring deflection. Air dampers have a stronger end progression than, for example, steel spring dampers. If you were to install a steel spring damper in a mountain bike with a linear characteristic, this would have a super smooth response, but the damper would bottom out due to the lack of end progression. However, this is not the case with a linear air shock as it offers more end progression. That's why a linear air damper can also be installed in a linear rear triangle.
further characteristics
Too high a breakaway torque results in an uncomfortable, wooden response and the wheel has no traction. Here, under certain circumstances, tuning dust wipers with less friction can help. Optimum maintenance is definitely an advantage.
If the characteristic curve is too flat in the middle section, you will rush through the spring travel and the chassis will not generate enough counter pressure. If this is the case, simply increase the compression level a few clicks.
If the final progression starts too early, you cannot use the suspension travel. If there is not enough end progression, the spring elements often bottom out. This is not only inharmonious, but also puts an unnecessarily heavy burden on man and machine. Add or remove volume spacers here.
Fox DPX2
Fox Float DPX2 - the dampers DPS and X2 were combined here, because the DPX2 should combine the best of both worlds. It should combine the downhill performance of the X2 with the easy adjustment of the trail damper DPS.
Technical information
- air spring
- Progression adjustable (via volume spacer)
- Three preset compression modes (selectable via lever on the damper)
- Open mode compression damping finely adjustable (3mm allen key)
- Rebound adjustable without tools
- Metric installation lengths available
- Trunnion mount available
Price: 739, - Euro
settings
With the DPX2, Fox uses the damping design of the X2 for the finest response. The Dual Piston System (DPS), on the other hand, comes from the Float X and thus provides the three platforms Open, Medium and Firm. The EVOL air chamber has also been revised and is intended to provide a softer response in the first 25% of the suspension travel by enlarging the negative air chamber care for.
The DPX2 can convince with additional features. On the one hand, the reservoir could be made smaller compared to the Float X. On the other hand, at 418 grams, it is a whopping 138 grams lighter than its big brother, the X2.
The new position of the rebound adjuster is a plus point. While you had to fiddle around with a tool on the Float X, the adjustment on the DPX2 is easily accessible in the form of a screw. Opposite you will find the lever for the damper platform, which as usual is divided into open, medium and firm. In open mode, the low speed and high speed compression can be adjusted very finely with 10 clicks. A 3 mm Allen key is required for this. The 3mm allen key adjusts high- and low-speed compression in open mode, so it affects both oil channels of the compression stage. The blue dial only affects low-speed compression.
Tips&Tricks Video: FOX suspension Friday – adjust air dampers correctly
-Setup
The air chamber can be opened in no time at all and provided with suitable spacers for the right puncture resistance with the right negative spring deflection. Completely deflate the damper and carefully unscrew the air chamber. This is where the volume spacer is located. Now you can increase or decrease the end progression of the damper by different strengths. Thanks to the colour-coded spacers in 0,2, 0,4, 0,6, 0,86 and 1,0 cubic inches, you have the choice.
The Fox DPX2 on the trail
Admittedly, whether a bike rocks when going uphill largely depends on the rear triangle and the single-pivot rear triangle of our Orange Stage 6 does a very good job of being inconspicuous.
Technical climbs in particular were a pleasure with the shock open, as the rear wheel was always able to follow the ground. The medium position tightens the rear end significantly with an increased low-speed compression stage and thus eliminates the remaining drive influences. The Firm setting increases the low-speed compression even more, but is still a bit away from a full lockout.
Downhill, the Fox DPX2 absorbs almost every small and large bump without further ado. Even with harder hits, the damper does not rush through the suspension travel, but offers support and sufficient feedback. For the final progression I installed a spacer of 80 inches with a rider weight of approx. 190 kilograms and 0,4 psi damper air pressure. As a result, I never had a breakdown during the test.
DT Swiss R414
The DT Swiss R414 was developed together with cross-country pro Nino Schurter. They found out that this damper is also well made for enduro use. Now the damper is also available in other sizes.
Technical information
- air spring
- Rebound adjustable without tools
- Three compression modes (via remote lever on the handlebars)
Price: 379, - Euro
settings
The DT Swiss R 414 is equipped with an air spring, which the manufacturer appropriately calls "Linè-Air". The reason for this is the linear spring characteristic, which is intended to ensure that the damper responds sensitively to small bumps, but does not rush through the spring travel and ultimately offers adequate protection against bottoming out. In order to achieve optimal response, the DT Swiss R 414 uses a generously dimensioned negative air chamber.
The scope of delivery includes the damper, a damper pump and the remote lever. The rebound of the damper can be adjusted with 40 clicks using a small wheel. Ultimately, you only move within a range of + - 5 clicks. The compression level of our model can be adjusted in three different positions with a remote lever on the handlebars. Open, Trail and Lockout.
Installation
Mounting the DT Swiss R2 is not as easy as with the Fox DPX414 damper, so I would like to go into more detail here. The damper is unusually mounted, when the damper is installed it can be easily rotated left and right. DT Swiss has special damper bushings that make this possible. The bushings are mounted in ball joints that sit in the damper eyes. In this way, the forces that arise when the frame is not perfectly dimensionally stable do not have such an extreme effect on the bearings and the damper. A bit of skill is required during assembly, as both sockets must be held, otherwise they will fall out on the other side. It is best to have a third hand ready to help you.
The DT Swiss R414 on the trail
The owner's manual states that the shock must be run with more air pressure than compared to other shocks. So I approached it with 220 psi with a driver's weight of about 80 kilograms. Maximum pressure on the damper is 333 psi. With a Fox DPX2, the maximum pressure is 275 psi, which is significantly less. Then I adjusted the air pressure again to 210 psi to get about 25% sag. I did a few laps in the bike park with it. I always rode the same route with both dampers. Many roots, stones, jumps and berms were offered on this test route.
The DT Swiss R414 responds very finely at first. The end progression felt too strong in the first laps. So I tried to ride with even less air pressure. I now had about 30%. Unlike the Fox, you can feel the impact on your foot much earlier here. With 30% sag, the shock was very easy to ride for my needs. Soft response at the beginning and plenty of bottom out protection at the end. I also didn't have the feeling that the shock would roar through mid-travel. The remote lever on the handlebars should also be interesting. This is perfect for longer tours or crossing the Alps. The three modes for the compression can be conveniently operated on the handlebars. Downhill, the DT Swiss R414 offers a lot of feedback and sometimes swallows harder hits.
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