For a long time, the word suspension fork had only one abbreviation for racers: SID. Now things are getting tight for Rock Shox, the inventor of the legendary race fork. Although the suspension pioneers are launching two successful forks on the market with the SID and the Duke, there are alternatives to the classic.
The design of a race fork sometimes places contradictory demands on the designer: good stiffness paired with a lot of comfort and, if possible, less than 1.5 kilos. This is why heavy steel springs are not used, but an air chamber is used instead. This causes two problems: a higher breakaway torque and a flatter characteristic curve. With the first generation of air forks, a lot of force was needed to set them in motion. Once this threshold was overcome, the forks dipped deeply and wasted part of the spring travel. The last few centimetres could not be used, but felt like a blocked bellows. The current forks only show this characteristic to some extent.
The manufacturers get a good handle on the unruly air cushion: in the Skareb, a steel spring works against the air chamber, the Look overcomes the breakaway torque with the help of the lever mechanism and in the Marzocchi and Rock Shox SID, a second air chamber works against the so-called positive chamber. At Fox, the extremely precise production ensures a smooth response - a solution that is as simple as it is expensive. Only because of the high price does Fox miss out on the overall victory, the function alone impressed us.
Many manufacturers successfully combat the flat characteristic curve: We like the suspension of the Rock Shox Duke, the Manitou Skareb and the Marathon S the best. Unfortunately, this makes it quite heavy with little suspension travel. This prevents it from winning the comfort category, which we would have expected from a well-tuned model with ten centimetres of travel. The Magura Quake could not be set up comfortably: The Quake has to be pumped up so hard that it barely responds to small bumps so that half of the stanchions don't dive away at the start of a descent. The Marathon SL from Marzocchi is similar. However, with its greater suspension travel, it compensates for this shortcoming and still feels comfortable.
Only a few forks in the test have this bonus: the working range is mostly around four centimetres. With the exception of the MX Comp, which is included in the price comparison, all forks are uncompromisingly designed for racing. Be honest with yourself: Do you see your fork as an emergency buffer and are you looking for direct feedback? Or do you sometimes go on tours where you want to take it easy? BIKE tester and Transalp winner Karl Platt is in favour of more comfort: "For me, nine centimetres of travel is the minimum on a tough marathon."
Our tip: If you can cope with more weight, go for the version with more travel. This gives you more room for manoeuvre in the set-up. In the case of the Rock Shox Duke, it's not even more expensive.
The suspension forks in this test:
Headshok Fatty Ultra, Fox Float 80 RLT, Loo, LSF 2, Magura Quake Air, Manitou Skareb Super, Marzocchi Marathon S, SL and MX Comp, Rock Shox SID Team and Duke Race, RST Aerosa HT
