The gravel trend has long since grown into a real boom and is readily fuelled by the innovative spirit of the industry. There is almost no handlebar tape, no item of clothing, no bag that is not available specifically for gravel use. Manufacturers are also being inventive when it comes to the gravel bikes themselves and their components.
Under the overarching theme of "comfort", an abundance of add-on parts are sprouting up to make off-road racing bikes even better equipped for off-road use. Special suspension forks, suspension stems, wide tyres, telescopic seat posts and flexible carbon rims are intended to close the ever-shrinking gap to the mountain bike hardtail.
In order to test what has worked on mountain bikes for decades or has already disappeared into oblivion (e.g. Girvin Flexstem), we put four promising comfort products, from suspension forks to flexing carbon rims, to the test. We also tested how wider gravel bike tyres affect riding comfort. In the tyre duel, we fitted identical wheels (Cadex AR 35) once with 40 mm tyres and once with 50 mm tyres (both Schwalbe G-One Bite). Our duels not only provide information about the function of the tyres, but also their usefulness on a gravel bike.
Suspension fork versus suspension stem
At first glance, the result of this gravel bike comfort duel seems clear-cut: what can a suspension stem do against a proper suspension fork? Even in the early years of mountain biking, the filigree suspension stems didn't stand a chance against the longer-travel suspension forks.
With the parallel-guided Freeqence stem, however, the tinkerers from the Allgäu have taken a completely new approach to the subject and, with a maximum stroke of 30 millimetres, even tease out the same suspension travel as the Gravel suspension fork from Rockshox - However, the Rockshox Rudy is also available in a 40-millimetre version.
In terms of compatibility, the point goes to the stem, which is available in three lengths (90, 105, 120 millimetres) with a steerer clamp of 1-1/8 inches. This is because the longer installation length of 425 millimetres means that the suspension fork (stem size 1.5 to 1-1/8 inches) currently collides with the vast majority of gravel bike frame geometries.
Off-road, both concepts are convincing and provide an aha experience compared to the gravel bike without suspension. Unevenness and bumps are much better compensated and kept away from the rider's hands. This not only increases comfort, but also significantly improves bike control.
As both systems have the same suspension travel and the air-sprung Rockshox fork also compresses an elastomer from half the travel, they feel very similar in direct comparison. The Vecnum stem responds even more sensitively to small vibrations than the suspension fork. On the other hand, the fork filters out roots and large bumps better on rough terrain - where you would actually be better off on a mountain bike.
CONCLUSION: Both the Rockshox Rudy suspension fork and the Vecnum stem noticeably increase riding comfort and thus ensure more safety and less fatigue on rough tracks. However, price, weight and compatibility clearly speak in favour of the Vecnum stem, which is therefore the smarter solution for gravel bikes.
Duel 2: Wide tyre versus comfort wheel
The American wheel and component manufacturer Zipp is an established name in the road bike sector. With the innovative Moto rims, Zipp has also expanded its commitment to the MTB market since 2019. With the 101-XPLR wheels, Zipp is extending its new technology to the gravel sector.
In order to create a particularly flexible rim that can withstand impacts and absorb vibrations, Zipp has dispensed with a hollow chamber in the special carbon rim. This should not only make the single-walled rim more comfortable to ride, but also reduce the risk of punctures and thus tyre and rim defects.
With an internal width of 28 millimetres, the wheels are very wide, cost just under 2000 euros as a set and weigh 1688 grams. For our comparison, we rode the wheels with Schwalbe's G-One Bite in a width of 40 millimetres. The competitor was a G-One Bite with a width of 50 millimetres on a Cadex AR 35 carbon wheel.
In order to do justice to the larger volume of the wide tyre, we reduced the tyre pressure by 0.4 to a total of 2.1 bar. In this setup, the difference between wide tyres and Zipp wheels was very small. Only when we pushed the minimum pressure to the limit (0.7 bar less) was the wide tyre able to set itself apart from the Zipp wheels with narrow tyres and more pressure. Traction and the damping of power peaks were then better.
CONCLUSION: In a direct comparison, the ten millimetre wider tyre with correspondingly lower tyre pressure is more noticeable than the flexible rim of the Zipp wheels. The wide tyres generate more traction and comfort. The optimum would certainly be a combination of both.
