Flex series - comfort for MTBs: The Vecnum freeQENCE suspension stem put to the test

In the late 80s and early 90s, when mountain bikes were still often ploughing through the terrain without suspension forks and with lifeless tyres, resourceful developers came up with the idea of integrating suspension into the stem. Various systems made up to 75 millimetres of suspension travel possible. For example, the legendary Grivin Flexstem used an elastomer to dampen vibrations from the ground. The problem with this was that the mini suspension could only react to obstacles such as roots or stones, but not to dips or grooves. It lacked the ability to rebound, or in other words, the negative suspension travel (SAG).

What's more, the handlebars on the nostalgic spring stems constantly changed their position on a vertical axis, which had an impact on the geometry and made the riding experience "difficult to get used to" at best. More sophisticated was the parallelogram suspension of the Softride Suspension Stem, which was even used to win MTB world championship titles. However, even this approach did not really prove itself in everyday use with a weight up to four times higher than a standard stem and moderate steering precision. As suspension forks improved over time, suspension stems disappeared completely from the mountain bike market.

But then a new trend emerged that breathed new life into the approach: the gravel bike. Once again, sporty cyclists with rigid forks and narrow tyres rode through the terrain. On long rides over rough ground, a lot of vibrations can reach the rider's hands and arms. Potholes and the edges of stones or roots quickly take their toll on unsprung bikes: fatigue and pain can be the result. Vecnum has addressed this issue and developed a product that takes the spirit of nostalgic flex stems to a whole new level. And why not? Renewing an old idea with modern technology can be a promising strategy. On gravel and trails, the Vecnum freeQENCE is designed to reduce stress on the body and increase comfort. We have tried it out.

What the Vecnum freeQENCE promises

So what can bikers expect from the €299 Vecnum freeQENCE?? The suspension stem from Vecnum is said to filter up to 75 per cent of vibrations from the terrain when used with a rigid fork. As a result, the Allgäu-based company promises less tingling and numb hands as well as more safety, comfort and riding fun in technical passages. According to the manufacturer, this is made possible by a total of 30 millimetres of suspension travel integrated into the stem, which is divided into 20 millimetres of positive and 10 millimetres of negative suspension travel. Vecnum promises a linear characteristic curve with strong end progression for the purely mechanical suspension. The freeQENCE contains four elastomers, which should have nothing in common with the now frowned upon plasticisers of the 90s. Even the best suspension is useless without adjustment to the rider's weight. This is why a patented spring linkage can be continuously adjusted for riders between 50 and 120 kilos using a three-millimetre Allen key.

The Flex stem is available in 90, 105 and 120 millimetre lengths. These dimensions mean that the freeQENCE is predestined for gravel use. However, Vecnum approves the part for all unsprung bikes and also allows classic MTB handlebars with 31.8 millimetre clamps. As a mountain bike magazine, we tested the suspension stem on a hardtail with a rigid fork - a type of bike that has become rare, but is ideal for bikepacking adventures and training rides. Vecnum also shows the freeQENCE riding over trails in marketing videos on gravel bikes. Even jumps should be possible with it.

Details of the Vecnum freeQENCE stem

• Price: 299 Euro
• Weight: 284 g (90 mm, BIKE measurement)
• Suspension travel: 30 mm (20 mm positive / 10 mm negative)
• Adjustment range: 50 - 120 kg
• Handlebar clamp: 31.8 mm
• Rise: 3°
• Available lengths: 90 / 105 / 120 mm
• Special features: sprung parallelogram stem, only for bikes with rigid fork, titanium hardware, made in Germany

Stem with 30 millimetres of suspension travel

The special feature of the Vecnum freeQENCE suspension stem is its parallelogram design. In principle, it is a four-joint system which, in contrast to single-joint suspension stems, is characterised by a high degree of flexibility, such as the Redshift ShockStopThis should have no influence on the riding geometry. Even with a suspension fork, the front of the bike dips when compressing. However, the parallelogram stem absorbs vertical impacts without changing the geometry. In addition, the multi-link design means that the damping and suspension properties are not influenced by the lever length. This means that the suspension system always has the same vertical stroke, regardless of how much force is applied. Unlike stems without a parallelogram system, the Vecnum freeQENCE should therefore always behave the same, regardless of how wide the handlebars or how long the stem is. The suspension also wants to be independent of the grip position.

With four bearings, the Vecnum freeQENCE is a relatively complex design. The compact design should nevertheless guarantee high torsional rigidity and implement steering movements directly. High-quality individual parts made from milled 7075 aluminium as well as titanium axles and bolts should ensure minimal tolerances. To achieve maximum manufacturing quality, Vecnum produces the suspension stem entirely in-house in Germany. Compared to a suspension fork, this solution naturally saves weight. Our 90 millimetre long test stem weighs 284 grams and therefore has a weight disadvantage of around 150 grams compared to a conventional stem.

Tested: Vecnum freeQENCE Flex stem

Unlike other suspension stems or the spring-loaded RevGripsnothing needs to be adjusted on the Vecnum freeQENCE before fitting it to the bike. The elastomers are internal and not visible from the outside. The high quality of the milled aluminium parts and titanium bolts can be felt immediately in the hand. As the suspension stem needs some room to move downwards, Vecnum includes a template which, when placed on the steerer tube, ensures that the part can move freely. This can lead to problems with wide headset caps, for example on bikes with an integrated steering stop limiter. In this case, at least one spacer must be fitted under the stem, which also requires a clamping height of at least 42 millimetres, which is not exactly small. If things go wrong, the space on the steerer tube will run out or the cockpit cannot be positioned as low as desired. Apart from that, installation works just like with any conventional stem.

Even when stationary, the suspension of the stem can be visually recognised by the movement of the parallelogram. Vecnum recommends testing the freeQENCE directly on a rough track in the factory setting. This is a good thing, because in the basic setup, the suspension effect is noticeable from the first metre on rough gravel for a rider weighing 84 kilos ready to ride. Also undeniable: the end stops up and down. If the front wheel is lifted abruptly or pushed through the mini suspension travel by the rider, the freeQENCE makes it clear when it's over. However, as Vecnum has also damped the end stops, bumps are neither harsh nor unpleasant.

We also tested the Vecnum freeQENCE under laboratory conditions and were able to measure a downward deflection of 17.5 millimetres (spring force: 44.83 N/mm) with a simulated rider weight of 80 kilos and the basic setting of six revolutions. In the hardest setting, the deflection was only 8.6 millimetres (spring force: 91.65 N/mm). Finding a setting that suits the rider's weight is therefore essential. It's a shame that Vecnum doesn't provide a setup table.

The spring stiffness of the stem is set correctly when the maximum suspension travel is utilised without reaching the end stop. In our practical test, bottoming out could be provoked even in the hardest setting, but for the most part did not occur during normal riding. Incidentally, the ride feel with the Vecnum in the hardest setting, which is supposed to work up to 120 kilos, is similar to that of the Redshift Shockstop stem in the recommended setting for 61-84 kilos. This is also confirmed by our measurements in the laboratory and makes it clear that Redshift provides a firmer and Vecnum a more comfortable setup in comparison. Both stems are fully adjustable for heavy riders. However, riders weighing less than 60 kilos may benefit less from the effects.

The adjustment screw for the spring stiffness of the Vecnum stem allows a total of 20 full turns. Five turns are preset at the factory. Unfortunately, the setting is not locked and it is not possible to see how many turns the screw is currently at. The maximum or minimum setting must therefore always be assumed during setup. Patience and attention are required. In any case, finding the optimum setting requires a few test kilometres. However, once the preferred setup has been found, the freeQENCE requires little attention. The four high-performance bearings are self-lubricating.

In terms of riding performance, the Vecnum freeQENCE can be a real game changer for rigid fork bikes. It significantly reduces impacts from the ground and protects the rider's arms from premature fatigue. As the suspension stem effectively keeps vibrations away from the rider, the hands feel less stressed on long rides. If the unsprung bike crashes through a pothole, the ten millimetres of negative suspension travel actually helps to soften the impact. Of course, the mini-travel is not enough to completely smooth out holes and edges. It's more as if the suspension rounds off the handling of a rigid fork hardtail. This is especially true on descents. The riding experience on the freeQENCE is similar to a very short, but also very sensitive, very linear suspension fork.

Visually, the massive, wide body of the Vecnum freeQENCE is of course a matter of taste. However, the solid construction scored highly in our practical test with its precise steering and pleasant stiffness. Although the stem also bounces when pedalling out of the saddle, the minimal movement is hardly noticeable. This is due to the fact that the riding position always remains the same thanks to the parallelogram geometry. Relative to the frame, the handlebars are always in exactly the same position thanks to the parallelogram geometry. On steep descents, this has the advantage that the front does not tilt despite the suspension and there is no rollover sensation. Of course, 20 millimetres of positive and ten millimetres of negative suspension travel remain very minimalistic. However, for sporty, fast bikes that are mainly ridden on gravel, forest tracks and easy trails, the Vecnum freeQENCE has what it takes to be a serious, lighter and even cheaper suspension fork alternative. The ideal place to use the suspension stem is on a gravel bike - whether with a drop or flat bar. With the latter option, the boundaries to rigid fork MTBs become blurred.

Conclusion

The advantages of the Vecnum freeQENCE can be felt from the very first metre. If you are willing to invest the money and set-up time, the suspension parallelogram stem offers real added value for your rigid fork hardtail. Thanks to vibration damping, hands and arms tire more slowly. The suspension in the stem gives rigid bikes a small but valuable bonus of reserves. The parallelogram system maintains a high level of control at all times despite the suspension. All in all, the freeQENCE is able to make otherwise unsprung mountain bikes much more versatile, even downhill. - Jan Timmermann, BIKE test editor

Pro

• Adjustable on the move
• Reduces hand and arm fatigue
• Significant performance gain for rigid fork bikes
• Processing quality made in Germany
• Price and weight compared to short-travel suspension forks

Contra

• Price and weight compared to conventional stems