From the lab to the water: Freerace fork trees in a practical test - thin beats stiff

We recently presented 20 carbon and aluminium fork trees and measured them in the laboratory. This revealed clear differences in terms of bending curve, diameter and stiffness.

• Test: 20 booms for large sails in a lab test

Stiffness is often an important selling point for manufacturers. On the test bench, the differences were huge at first glance: extended to 2.10 metres and loaded with 20 kilos of weight, the softest aluminium fork moved almost 3.5 centimetres apart, the stiffest carbon model only 1.3 centimetres. Marketing specialists would advertise this as 2.6 times the stiffness without batting an eyelid. That wouldn't even be wrong, but it wouldn't be a statement as to whether this offers any advantages on the water.

The grip diameter of the test forks was between 28 and 33 millimetres including the pad - which, on the other hand, can be clearly felt by anyone, even without special sensitivity, when rigging. We therefore wanted to know how the measured values are reflected in practice: Is an ultra-stiff carbon fork really so wonderfully crisp in the hands that you can get over the thicker diameter? Or is "super-stiff" perhaps even super-meaningless in the end? Five representatives from the laboratory test should provide the answers on the water:

• Duotone Silver Mega Slim 180-240: The thinnest aluminium fork at 30 millimetres, weight: 2.86 kilos
• Goya Carbon 180-240: The stiffest fork, 31.5 millimetres in the grip area, with a solid 38-millimetre end piece, weighing 3.18 kilos
• GunSails Select 170-220: Full carbon fork with thin 29er bar and slim end piece, significantly softer than the Goya fork, 2.4 kilos light
• NeilPryde Carbon E 2.6 175-225: Freerace carbon fork with a slim 32 mm diameter throughout, weighing just 2.6 kilos
• Unifiber Alu HD 280-230: The stiffest aluminium fork, 33 millimetres in diameter, weighing 3.47 kilos.

Stalling during the practical test

On Test day, the trade winds on Tobago The 7.7 test sails can be pulled a little flatter and you can make big cheeks in the gusts. The test forks are about half extended for this sail size. So hook in, tighten up and put in some fast runs and gybes. A few pumping strokes won't do any harm either. How does the boom flex? How hard do you have to grip? After six runs, we meet up to exchange ideas.

"That the Goya Carbon is the stiffest fork on the test bench, you can feel it immediately on the water", summarises tester Tobi Frauen, "nothing moves at all, even when pumping. However, the fork feels quite bulky to me, especially when I reach far back on the very thick end piece when jibing."

The fact that aluminium forks can also be really stiff is proven by the Unifibre Alu HD. Not only are the bars noticeably stiffer here, "but also the fit of the fork with the solid head piece on the mast," says tester Manuel Vogel. "Just like the Goya carbon fork, the Unifiber Alu feels quite bulky to me, which is due to the thicker diameter of the bars and the higher weight. For racers who fully utilise the adjustment range, the priorities may be different. For freeriding, even with a camber sail, I would always focus on grip comfort and weight," concludes Manuel.

Carbon forks don't bend in crashes and landings. Stiffness is of secondary importance to me. That's why I use a thin carbon fork in my private life." (Manuel Vogel)

Aluminium forks are also stiff enough for freeriding and freeracing

It was precisely this combination of thin diameter, low weight and good stiffness that epitomised the GunSails-Select-Carbon fork. "Here you also have a thin tube when jibing, which is very comfortable. You also notice that the centrifugal mass is lower when shifting and rotating the sail. The fact that this boom is almost a kilo lighter than the stiffest models from Goya or Unifiber is much more noticeable on the water than the slight loss of stiffness," says Manuel Vogel.

Even the thinnest aluminium fork that Duotone Silver Mega Slimscored highly with our testers. "When pumping and chopping, you definitely notice that the fork flexes more than any carbon fork," says tester Frank, "but it doesn't make me ride slower or start later. The stiffness is absolutely sufficient for freeriding. Even with my customers in the shop, the stiffness of a fork usually plays a subordinate role, it's almost always about light weight and spar diameter."

In the surf shop, hardly any customers ask for the stiffest fork. It's all about the diameter and the weight." (Frank Lewisch)

The NeilPryde Carbon E 2.6 turned out to be as good a compromise as the GunSails fork in practice. In terms of price, the fork, with not quite 100 per cent carbon content, is below the high-end race forks - and also in the continuous slim diameter. It lacks the martial end piece with the arm-thick vario tubes, "which no freerider or freeracer actually needs", as tester Stephan says. "Even for our freerace tests, these forks are more than stiff enough and easy to grip."

surf conclusion: Thin beats stiff, unless ...

The differences in stiffness found in the measurement can be felt when surfing - but are often of secondary importance. Instead of a super-stiff feeling, it is the grip diameter and weight that determine how much fun you have on the water. So is "super-stiff" meaningless? Not necessarily, because if you weigh a few kilos more (than our testers between 80 and 91 kilos) and want to exhaust the adjustment range of the forks with large sails, you should definitely go for a really stiff carbon race fork.

For all those who can do without that last bit of stiffness - and that's probably most freeriders and freeracers - thin carbon forks are the ideal compromise between handling, riding fun and still very good stiffness. You can also utilise almost the full adjustment range without having to worry about bent bars. Aluminium forks remain the cheapest alternative with usually more than acceptable stiffness. However, the adjustment range should not be fully exploited with aluminium tubes: not only because aluminium forks lose significantly more stiffness in the process, but also for reasons of durability, because you may end up paying for it with a bent aluminium spar in the event of a skid.

• The laboratory values of the tested fork trees at a glance