Test 2018: Suspension fork for gravel bikes from Lauf Forks - Lauf Forks: Suspension fork for gravel bikes put to the test

"Lauf" is the Icelandic word for "leaf". A look at the design of the suspension fork of the same name shows what this has to do with it: six leaf springs connect the front wheel mounts to the fork blades. This idea is not entirely new, but the technical possibilities are new thanks to the use of modern composite materials. Benedikt Skulason, inventor of the fork, used to develop leg prostheses. This gave him access to a highly elastic, extremely break-resistant fibreglass material from which the twelve springs are made. They are said to neither fatigue nor wear out. As the mechanism also requires no bearings or seals, the fork is maintenance-free.

Lauf Forks now also offers the "Grit", a version designed for gravel bikes. For our test, importer Tehava fitted the fork to a T5G frame from US titanium manufacturer Litespeed. In the test lab, the Grit doesn't show any weakness. The measurement on the BIKE fork test bench resulted in 28 millimetres of travel. Mountain bikers will smile pityingly, but for gravel biking 28 millimetres makes a huge difference compared to a rigid fork. Although the springs look delicate, they bravely withstand lateral forces: 39 N/mm is an average value for road bike forks, which is not expected to cause any problems in practice. The weight of 940 grams is also acceptable considering the suspension.

Divided opinions

More exciting is the question of how the thing drives. Opinions are divided: The comments of the five testers range from "sensational" to "unrideable". But where do these stark differences in perception come from?
All riders confirm that the Grit responds very sensitively. As neither seals nor joints inhibit the reaction, the fork reacts much more directly to vibrations and minor bumps than telescopic forks. If the shocks are not too violent, it doesn't matter that the Grit is not damped due to its design. The limits only become apparent when the bumps become more severe or in quick succession, for example on root passages. Then the fork tends to bounce significantly and challenges the rider in a similar way to a rigid fork.

Strong influence on the steering

The fact that the fork nevertheless elicits such different reactions from the testers is probably mainly due to its influence on the steering geometry. The Grit is around 10 to 30 millimetres higher than typical large series forks. As a result, the steering angle is flatter and the bike steers more sluggishly. For the Litespeed frame, the Grit results in a steering angle of 70 degrees; the normal angle is 72 to 73 degrees. Two riders found the test bike to be downright stubborn, especially when pedalling out of the saddle, and unpleasant to ride in tight bends.

However, this is not the final verdict on the Grit. Lauf Forks recently announced a gravel bike with frame geometry adapted to the fork for 2018. The Grit is also set to become lighter and laterally stiffer. It is quite possible that the fork will only realise its full potential with specially adapted frame geometry.

PLUS Sensitive response behaviour, maintenance-free
MINUS Significant change in steering geometry

Price 829 Euro
Info www.laufforks.com

Dimensions
Steerer tube 1-1/8 x 1-1/4 inch
Overall height (thru axle-fork crown) 414 millimetres
Thru axles 12 and 15 millimetres
Brakes Flatmount
Maximum tyre width 42 millimetres