Lauf Grit fork

It's one of the most unusual looking products ever to pass through the road.cc office, but get past its radical appearance and the Lauf Grit fork offers some useful bump-absorbing benefits for off-road gravel riding. There are limitations to the design, though, and it's not cheap.

Lauf is an Icelandic company and came up with its novel fork design a couple of years ago, first for the mountain bike market and more recently adapted for gravel and cyclo-cross bikes. With the rapid growth of gravel and adventure riding in the past 12 months or so the Lauf has been popping up on more and more forum conversations about bike setups.

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The fork comprises a full carbon fibre construction from the bottom to the steerer tube, with a separate carbon section housing the dropouts, and 12 short glass fibre plates joining the two halves. The brake hose is routed externally with a few zip tie anchor points and a steerer tube bung and axle is supplied in the box.

Those glass fibre plates essentially act like a leaf spring and allow the front wheel to move up and down to the tune of 30mm. It's not a lot, but the idea is that it's enough to take the edge off harsher bumps and impacts without drastically altering the geometry of the bike by raising the front end too much. The axle-to-crown measurement is 409mm with Lauf factoring in about 6mm of sag when the bike is weighted.

I tested the 15mm version but a 12mm version is also available, and with the latter rapidly becoming standard on all new road and adventure bikes, all bases are covered. You can't switch one from the other, but most good hubs can be adapted for either axle diameter with replaceable end caps.

There's clearance for up to 42mm tyres on a 700C rim or 2.1in tyres on 650B wheels. The flat-mount disc mount supports 160mm rotors but I had to use an adapter to fit my post-mount SRAM Rival brake callipers.

It does add weight compared with a regular rigid fork. It's 1kg with an uncut steerer tube, versus about 375g for the fork it replaced on the Open UP I used as the test bed. Unless you're a weight weenie that sort of difference isn't going to be a major issue and you do have to factor in the benefits that the 30mm suspension is going to bring when tackling rough terrain versus the small weight penalty.

But 'I've already got fat tyres, that's enough suspension surely?', you might be wondering. Lauf makes the claim that when measured on a 50psi 38mm tyre, the Grit gets you roughly twice the suspension travel, so if the tyre provides 6mm of deformation, the fork gives an extra 12mm. It's more bump absorbing for you, basically.

I fitted the Lauf to the Open UP I tested for a couple of months, with the review period culminating in the Dirty Reiver 200km gravel event, a suitable test for the fork. Before that, I rode the fork everywhere, from road rides to mountain bike trails and everything in between, including plenty of local bridleways and the gravel roads of Salisbury Plain. My first observation was that it doesn't make any real discernible difference to the fit and geometry of the bike, and the handling is unchanged.

The good...

It creates a smoother ride. It works really well on smaller bumps and ripples, filtering out the vibration very noticeably compared with the rigid fork it replaced.

There's less vibration through the handlebar, and that's a good thing on longer rides. It was a real benefit on the near-200km of gravel roads that make up the Dirty Reiver.

Handling at speed and tackling fast descents is an area where the Lauf shines. It provides extra traction on fast fire road descents with a washboard surface that would see a regular rigid fork skipping about wildly. With the Lauf, the front tyre was able to maintain contact with the surface for a more predictable, and safer, ride.

You can also be less choosy about your line choice, as the fork soaks up the hits well, letting you concentrate on powering through the rough, relying on the Lauf to dissipate the bigger impacts.

There's also virtually no pedal bob, a symptom of a suspension fork and why many have lockout dials for coping with smoother trials. When you're sat in the saddle the Lauf doesn't activate unless the front wheel encounters a decent sized hole or bump, so that's good. Climbing out of the saddle does get the fork moving but it's controlled and acceptable; it certainly doesn't dive uncontrollably.

There are no moving parts and that means zero maintenance. It's also strong as hell – I've done my best to twist and overload the glass fibre springs, but despite twatting the front wheel purposely into massive potholes (it's a brave job, but someone has to do it) it hasn't shown any sign of distress. So several months of riding and zero durability or reliability concerns.

And the not so good...

There's a limitation to the impacts the Lauf can cope with. On very high-speed square edge impacts, such as hitting the edge of a pothole or piece of broken road, the Lauf will initially soak up the impact before releasing the energy with quite a jolt through the handlebar. It's a reminder that it's not actually a suspension fork and 30mm of movement isn't very much at all.

It still allows you to plough through rough terrain with more abandon than a rigid fork, but you can't be reckless like you can with a suspension fork, and so you still need to pick your line carefully at times. On one very fast descent in the Dirty Reiver, with lots of big steps, holes, rocks and slabs, I was able to drop my riding companions but I was at the limit of the Lauf's capability, and that I got through this section was more down to luck than skill.

There is also lateral movement detectable when you get out of the saddle and put loads of energy through the bar. This flex isn't so much a problem in all other scenarios. You can occasionally detect it through high-speed corners when really loading the front end, but you reach the limits of the fork's 30mm travel before you get to concern yourself with the unwanted flex.

Another drawback is an inherent flaw in the design: there's no way of tuning it. That means the Lauf has to cope with riders across a wide range of weights. I'd like a bit of a plusher ride for my 67kg weight. There's also no rebound damping and that's something it needs with the bigger high-speed impacts, a reminder that it's no suspension fork.

Conclusion

If you can get past the looks, and the price tag, and the extra weight, and are comfortable with its limitations, there's a lot to like about the Lauf Grit fork. There have certainly been times when I've been thankful for its ability to remove the harshness of impacts when riding rough gravel roads, but I know I would equally survive without the Lauf.

Verdict

Works a charm on smoother gravel roads but has it limitations – namely its looks, price and weight