It's upside down, costs twice as much and was the first choice of the pro teams at this year's Cape Epic. We are talking about the RS-1, the latest fork from Rock Shox. Thanks to its upside-down carbon design, it is currently the most spectacular new product on the fork market. We were therefore eagerly awaiting this first, major comparison test to find out whether the attractive appearance is backed up by competitive functionality. Because it's not just Rock Shox that's doing something. There are some very promising innovations in the lightweight 29er suspension fork segment in particular.
We tested these 29 inch All Mountain and Cross Country suspension forks:
- ALL MOUNTAIN 29":
- Formula Thirty Three
- Fox 34 Float CTD
- Rock Shox Pike RCT3
- SR Suntour Auron RC2
- X-Fusion Trace RL2 (BIKE tip: price/performance)
- CROSS COUNTRY 29":
- Bos Dizzy XC 100
- DT Swiss OPM O.D.L (BIKE tip: price/performance)
- Formula Thirty Three
- Fox 32 Float 29 CTD
- Magura TS8 R DLO ²
- Rock Shox RS-1 (BIKE tip: test winner)
The power density has never been higher, and the test candidates have never been closer together in terms of weight. Just 80 grams separate the lightest from the heaviest race fork in the test field. In addition to Rock Shox's upside-down offensive, French suspension specialist BOS is also entering the short travel market. BOS has been an established name in the enduro and downhill sector for years, which is why we were particularly looking forward to the new Dizzy XC, which comes without a remote lever on the handlebars. An essential tool that racers sorely miss for short intermediate sprints and uphill sections. The Formula Thirty Three is not completely new, but this year it has a remote lever, even if the lever has too long a travel for quick locking. Magura, Fox and DT Swiss, who are also launching a completely revised fork with the OPM series (One Piece Magnesium), complete the test field of 100-millimetre forks. In addition to the small differences in weight, the wide price range is surprising. The gap between the Magura TS8 and the € 1658 Rock Shox RS-1 is an incredible € 909.
Within the all-mountain class, it's the other way round. The difference in price is a reasonably moderate 350 euros, but the weight is almost 500 grams - and that with an identical suspension travel of 140 millimetres. At just 1677 grams, the Formula Thirty Three with its slim 33 millimetre stanchions weighs the least. This makes it the lightest 29er all-mountain fork known to us. In combination with the super-sensitive response behaviour, it is a good choice for touring bikes where weight is also a priority. The other side of the coin is the rather low stiffness for this suspension travel and the restriction to brakes with a maximum disc diameter of 180 millimetres. Heavier riders should therefore opt for models with thicker stanchions. In contrast to the Formula, the slightly dusty Fox 34 is in a different class with its weight of well over two kilos. However, the significantly lighter successor to the 34 (see BIKE 4/15) has already been presented. When it comes to weight and stiffness, a Rock Shox Pike is of course a must. Thanks to its 35 mm stanchions, it fulfils both requirements very well and is also not overly expensive. The two cheapest forks in the test come from SR Suntour and X-Fusion. For 649 euros, the Auron is a versatile, adjustable and very stiff all-mountain fork that weighs just over two kilos. Compared to the rest of the field, however, the Auron lacks sensitivity, making it feel somewhat sluggish and lifeless overall. In contrast, the X-Fusion Trace, which is only 50 euros more expensive and 100 grams lighter, offered significantly more comfort. Only sporty riders might miss some counter-pressure in steep terrain due to the non-adjustable compression damping.
But back to the 100-millimetre class. In theory, the question of whether an upside-down fork makes sense can be justified by the higher sensitivity due to permanently lubricated seals and a lower unsprung mass. The big disadvantage is the low steering precision and the time-consuming wheel change, as the fork tubes are not connected to each other via a bridge and can twist. Rock Shox tries to increase the stiffness via a special front wheel hub, which, as the measurement shows, is only partially successful. But how much stiffness is actually necessary? On the trail, our test fork was extremely sensitive and offered perfect traction. The low torsional stiffness is noticeable both positively and negatively. In rocky sections, the fork finds its way and weaves its way through without the front wheel bouncing due to strong lateral impulses. In riding situations with a lot of weight on the front wheel, for example in compressions, the fork feels a little soft. Overall, the RS-1 still achieved the highest score in our test. However, whether this is worth € 1658 is another question. That depends very much on personal taste.
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