Marcus Klausmann on upside-down forks: "The magazines have taken this to the extreme"

He knows his way around springs, shocks and high speeds: Marcus Klausmann is a German mountain bike legend and 15-time German downhill champion. With World Cup successes and decades of experience, he is one of the most influential figures in the sport.

Today, the technology fan passes on his knowledge to the next generation as a coach and runs a suspension service Klausmann Suspension. We spoke to the tech fan about upside-down forks, zeitgeist and why stiff is not always better.

BIKE: Marcus, upside-down forks are making a comeback! Smaller labels like IntendDvo or Manitou have been selling such forks for a long time. But now a single crown prototype from suspension giant Fox has been spotted, which is soon to be presented as a series. Cause for celebration?

Marcus Klausmann: Why not? Upside-down forks are familiar from motorsport, such as MotoGP (the highest racing class within the Road Motorcycle World Championship, editor's note). The advantage: the oil is always at the seal - this improves the response behaviour. The disadvantage: slightly less stiffness. But is that really a disadvantage? In recent years in particular, it seems that many people are once again appreciating the advantages of more flex. The bike finds its line more easily and the rider's arms are spared.

>> Fox 36 & 36 SL - now almost as stiff as the big 38

The old question: is stiffer really always better?

Exactly. This was taken to extremes for a long time - even by specialist magazines like yours. Soft products were penalised. The manufacturers reacted: Fox suddenly installed the stiffer Fox 38 in enduro bikes, while the Fox 36 was demoted to an all-mountain fork. RockShox did something similar with the ZEB and the Lyrik.

In downhill racing, there is now a clear trend towards more flex. Frames, handlebars and wheels are increasingly being made from aluminium again instead of stiff carbon. The dictate of low weight has also become less important. Suddenly it is acceptable for an enduro bike to weigh over 16 kilos. Customers are also realising that light is rarely stable.

>> Is a stiff MTB frame always a better frame?

How do you explain this change?

Zeitgeist is difficult to analyse. Perhaps it is simply the experience of the buyers - for example after a week's holiday in Finale Ligure. After that, you know that a lightweight bike is usually less robust. And if you've ever seen a video of a broken carbon handlebar, you might prefer to buy aluminium next time. Back then, carbon was a must for marketing reasons, but that's no longer the case.

Back to the upside-down trend: why now?

I think the market is ready for it now. The idea is not new. The manufacturers have probably pulled old concepts out of the drawer that nobody dared to publish at the time.

As a thoroughbred racer, you're in favour of softer materials - that surprises me. Don't racers actually prefer things to be taut and stiff?

No. Commencal, for example, uses steel swingarms - and not because of high stiffness, but to reduce vibrations. In the last three or four years, hardly any new carbon downhill bikes have come onto the market - for precisely this reason. Flex brings comfort and conserves energy, even for racers.

That's another reason why bikes are getting heavier - are you relaxed about that too?
In the all-mountain, enduro, freeride and downhill sectors, the trend towards heavier bikes has been accepted - but mainly because of the increased durability.

Is there still a lot of development potential for forks?
The fork is not being reinvented, if that's what you mean. The technology is at an extremely high level. The top cartridges from Fox, Rockshox or Öhlins are all very close to each other - even if there are differences.

How did you experience the introduction of the massive Fox 38 as the new enduro fork?
I didn't understand that. It was a trend - I don't know who started it. The 36 was labelled an all-mountain fork, similar to the Lyrik from Rockshox. But it still fits well in the enduro segment. Perhaps the bulkier look of the 38 also played a role.

What role does body weight play in the choice of fork? Does it make sense to go for a Fox 38 or Rockshox ZEB from 90kg instead of a 36, Lyrik or the new upside-down fork?
A stiffer fork can make sense from 90 kilos - but it doesn't have to. In my experience, riding style has more influence than weight. Many of my customers like to experiment - and heavier riders in particular often deliberately opt for the slightly more flexible models.

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More about Marcus Klausmann

After the end of his active career in 2016, which he announced due to cardiac arrhythmia, Marcus Klausmann continued to be involved in mountain biking. Among other things, he worked as a coach and mentor for up-and-coming talent, for example as part of the "Propain Gravity Kids" project.