Bike park approval, 170 millimetres of travel and up to six adjustment options - these are the common features of this test field. We conclude the third part of our mega suspension fork test with eight enduro suspension forks between € 842 and € 1760. A total of 33 different models includes.
This time our route took us to the bike park, because the massive enduro forks with air and steel springs are hungry for big chunks. But before the forks get to the food bowl - i.e. the first descent - a veritable setup orgy awaits.
First the setup marathon: spring stiffness, damping, high & low speed settings
As the suspension travel increases, not only does the downhill potential increase, but also the wealth of setup options. Most of the enduro suspension forks we tested have six parameters that have a significant influence on the riding experience.
In addition to the spring stiffness, the compression damping can be adjusted for fast and slow stroke sequences on most forks. Some manufacturers such as Fox and SR Suntour also use separate high- and low-speed adjustment for rebound damping. The rest of the field is limited to a simple rebound stage.
In addition, the end progression of almost all suspension forks with air springs can be adjusted using volume spacers. On the forks we tested, we rode the factory standard setup on so-called tokens and recorded the spring characteristics accordingly on our test bench.
Two positive air chambers
Another option for adjusting the characteristic curve and thus the driving behaviour characteristics is the Era V2 from EXT. The fork utilises two positive air chambers with two separate valves, which must be filled in the correct order. The pressure in the smaller chamber not only changes the end progression, but also the course of the characteristic curve in the middle spring travel.
Steel vs. air springs: Which is better for enduro bikes?
But you can also do it completely without air. With the Marzocchi Bomber Z1 Coil and the Formula Selva C there are two suspension forks with steel springs in the test. The sag can also be adjusted here via the preload of the coil spring, as long as the rider's weight matches the spring rate of the installed steel spring.
Marzocchi specifies a rider weight of 68 to 82 kilos for the medium spring used as standard. If you are outside the specified range, the only solution is to change the spring, which, apart from the higher weight, brings us to the main disadvantage of the steel spring.
But of course there are also arguments in favour of a steel spring: steel spring forks and dampers require fewer seals, which reduces friction and therefore improves the response behaviour. In contrast to the steel spring damper, however, the steel spring fork does not benefit from better heat dissipation because the damping works separately from the spring anyway and is not enclosed in an air chamber.
Furthermore, the steel spring works linearly over the entire course and provides constant counter support. Particularly in the early years of air suspension systems, some spring elements tended to sag, as the characteristic curves in the centre area were degressive. However, the lack of end progression is both a curse and a blessing. On the one hand, steel suspension forks with linear springs offer less protection against bottoming out, but on the other hand they do not skimp on suspension travel.
However, even in a direct comparison on the trail, it is very difficult to distinguish between steel and air forks in the enduro suspension forks in the test. Especially when it comes to sensitivity and response behaviour, modern air forks have made up a lot of ground. Thanks to ever larger and self-filling negative chambers, good air forks work with absolutely equal sensitivity.
38 mm stanchions not only provide rigidity
Even visible from the outside, a lot has happened to enduro suspension forks. Fox, Rockshox and SR Suntour rely on massive 38-millimetre stanchions for their long-travel forks to optimise stiffness. The rest of the field uses 36 mm stanchions or, in the case of Formula, even 35 mm. Our measurements from the test lab confirm the positive effect. In terms of braking stiffness, the 38 mm forks offer 25 to 50 per cent higher values compared to the slim Formula.
Series dispersion
The fact that not every suspension fork always works equally well left a somewhat bland aftertaste. As we also tested enduro bikes on the same routes following the fork test, we were able to notice differences in function even with identical fork models and the same setup.
The reason, we suspect, is series variation. On suspension forks, very small tolerances determine smooth operation. Even during assembly, the amount and distribution of grease and oil can make a significant difference. So in the end, it's not just the right setup that determines perfect function if you've got hold of a proverbial off-the-shelf model.
CONCLUSION: Enduro suspension forks with 170 millimetres in the test
The Rockshox ZEB wins this test with a narrow lead over the Fox 38. Compared to the racy 38, the ZEB offers a tick more comfort and is easier to set up. With an equally solid performance, the X-Fusion Trace secures the price/performance tip as the cheapest fork in the test. - Peter Nilges, Test Manager BIKE
Enduro forks 2023: The models in the test
DVO Onyx SC D1
The Onyx from the American manufacturer DVO offers a wealth of adjustment options. The negative spring can also be preloaded using the OTT function, which influences the response. As a result, the fork is sensitive, but sinks deep into the suspension travel with little compression. With more compression, it is firmer, but offers less overall control and traction than a Fox or Rockshox.
EXT Era V2 LT
The Italian ERA V2 is high in its travel and offers very good counterpressure for a sporty riding style. In contrast to the 130 mm version already tested, however, the long version is more aggressive even with low compression damping and lacks comfort, which leads to fatigue on long descents. Our test fork made an annoying clacking noise when rebounding. Very expensive at 1760 euros.
Formula Selva C
Alongside the Marzocchi, the Selva C is the second suspension fork with a steel spring in this test. Nevertheless, the weight is low. Due to the slim 35 mm stanchions, the Selva has a low stiffness. On the trail, however, it responds finely and filters out even fast hits with ease. Even with little compression, the support is excellent. In rough sections, the absorption capacity could be better.
Fox 38 Factory Grip 2
The Fox 38 fulfils our high expectations and delivers a head-to-head duel with the Rockshox ZEB. In direct comparison, the setup is a little more complex and the Fox rides a little racier and firmer despite the best sensitivity and is high in its travel thanks to the good damping control. Even with less compression damping at 38, the ZEB delivers a touch more comfort.
Marzocchi Bomber Z1 Coil
The Z1 Coil uses a steel spring instead of air and works very sensitively and actively. This generates a lot of traction and offers a high level of comfort. In order to maintain sufficient counter-pressure and prevent excessive bottoming out, it makes sense to use a lot of compression damping. There is no ratchet on the adjustment. In terms of weight, the fork with slim 36 mm stanchions ends up at the rear end.
Rockshox Zeb Ultimate
The ZEB Ultimate takes the test victory by a narrow margin and can hold its own against the Fox. In direct comparison, the ZEB delivers a tick more comfort and also smoothes out rough sections with aplomb and control. In addition, the setup is relatively easy, the fork weighs less than the Fox with very high stiffness and is also cheaper.
SR Suntour Durolux 38 EQ
The massive Durolux is the heaviest fork in the comparison, but also offers the highest braking stiffness. While the fork reacts very well to subtleties when riding slowly, it passes on fast impacts to the rider quite unfiltered, which leads to rapid fatigue. Our test fork had noticeable bushing play on both sides. There is no air pressure recommendation on the fork.
X-Fusion Trace 36 HLR
At 842 euros, the X-Fusion Trace is not only the cheapest suspension fork in the comparison, it is also the lightest. Despite the slim 36 mm stanchions, the stiffness is in the green zone. The Trace reacts pleasantly sensitively to small bumps and also digests quick hits. Compared to the top forks, the X-Fusion doesn't have quite as much travel.
