Cervélo ZFS-5 - Test marathon bikes: Fun & gas with the down-country fully from Cervélo

Cervélo has only recently entered the mountain bike market. The Canadian label has made a name for itself with sporty road racers and triathlon bikes. However, as some road bike athletes are also interested in off-road cycling, Cervélo decided to develop its own MTB line. The result, in close collaboration with XCO World Cup racer Milon Vader, is this the ZHT-5 race hardtail Cervélo equips the latter with either 100 millimetres of front and rear suspension travel for top racing use or 120 millimetres for more technically demanding courses. Particularly in the marathon full-suspension sector, many well-known manufacturers, such as Cannondale, Giant/Liv or Specialised on a lightweight frame platform with a certain amount of extra suspension travel. The advantage: on the long distance, additional reserves should save valuable energy on the descent, which will be available again on the next climb. For the practical test at the Alpentour Schladming multi-day marathon, we also opted for the version with more travel, the Cervélo ZFS-5 120 GX AXS model to be precise.

However, 20 millimetres more travel is not the only difference between our test bike and the race base Cervélo ZFS-5 100. In addition to the longer suspension elements, a telescopic seatpost, wider handlebars and more heavily profiled tyres are intended to strengthen the downhill capabilities. The carbon frame with flex pivot rear triangle and two bottle cage mounts remains the same. In our marathon fully shootout at the Alpentour Schladming, we tested the Cervélo ZFS-5 in a direct comparison with the Mondraker F-Podium and the Storck Adrenalin.2. Compared to the other two candidates, the Cervélo exudes the strongest down-country vibes. Maxxis Rekon tyres without a race name suffix, 780 millimetre cockpit width and 180 millimetre dropper hub are supposed to contribute to the downhill account. Will this be at the expense of marathon suitability?

We also tested these two marathon full-suspension bikes for their suitability for racing:

>> MONDRAKER F-PODIUM RR

>> STORCK ADRENALIN.2 PRO

Battle of the giants: Cervélo ZFS-5 vs. queen stage

The proof was in the pudding Cervélo ZFS-5 on the second day of the Alpentour Schladming, the queen stage with 70 kilometres and 2760 metres of altitude. Immediately after the start in the pedestrian zone of the Alpine town, a neutralised asphalt route followed until the race release at the first gravel climb. In the tumult of the 400 starting racers, the Cervélo swims a little further back here. The higher wheel weight and the heavier rolling tyres, especially compared to the Storck, are clearly noticeable on the first few metres of road. On flat terrain, the ZFS-5 pulls away more comfortably than the Mondraker. In this comparison, it is clearly the slowest bike for flat sections. With the 32 t chainring, the maximum gear ratio of the Cervélo is barely enough to keep up with the high initial pace of the race. However, I will be extremely grateful for this later in the day.

Meanwhile, the riding position on the Cervélo Race-Fully is balanced. Despite the same frame size, it is nowhere near the length of the Mondraker and the 60 millimetre short stem puts the rider in a less stretched, more comfortable position. I lowered the cockpit for a little more race feeling. In the second half of the queen stage of the race, I realise for myself that the seat angle of 74 degrees is the slackest in the test. On the steep ramps of the Schladming mountains, the ZFS-5 lacks a little pressure on the pedals compared to the 2.4 and 2.5 degree steeper competition. As the front wheel rears up towards the sky at a twenty per cent gradient, I sit at the very front of the saddle and still struggle to convert my dwindling power into efficient propulsion. Panting, I shift into the easiest, most power-saving gear. The Sram GX Eagle AXS Transmission shifts gears smoothly and better than the drivetrains on the Storck and Mondraker, even under load.

Cervélo ZFS-5 120 GX AXS: Good deal, but suspension with weaknesses

In general, Cervélo has put together an attractive equipment package with the ZFS-5 120 GX AXS. In addition to the wireless drivetrain, the brakes and suspension also come from the mid-range component giant Sram/Rockshox. Race Face wheels and cockpit may not shine on the scales, but they leave nothing to be desired in terms of quality. Although marathon racers will not break out into cries of joy at the 12 kilos (frame size XL, without pedals), the complete bike weight of the Cervélo is absolutely fine in view of the equipment. The basis for this is the slim carbon frame, which at 1965 grams without shock and in size XL is by far the lightest in our comparison. Not necessarily to be expected in view of Cervélo's high-end road bikes and therefore particularly exciting: the Canadians have currently reduced the price of the ZFS-5 120 GX AXS from 6799 to 5799 euros. This makes it the cheapest bike in the test shootout and offers more equipment quality for the money than the competition.

Despite its fat tyres and moderate seat angle, the Cérvelo is by no means a bad climber. It's the comparison that counts. Compared to the down-country concepts of other manufacturers, which approach the discipline more from the trail bike side, the ZFS-5 pedals competently uphill. Compared to Storck and Mondraker, however, the Cérvelo in this configuration also falls behind on steep climbs due to its suspension. When pedalling, the rear suspension bobs constantly in open mode. Even with the compression lever closed, the shock can't be kept completely still when pedalling. Stupid in a race where any loss of power is painful. Just like the Storck, the ZFS-5 lacks a handlebar remote for suspension control. In the heat of battle, this is a clear disadvantage compared to Mondraker.

What the Cervélo lacks in pedalling efficiency, it makes up for in traction. On the second day of the Tour of the Alps in particular, there are many metres of elevation gain on trails. Here, the rear tyre clutches noticeably into the ground and the chassis sticks to the ground. Root edges can sometimes disrupt the flow, especially when your legs are tired. Not so on the ZFS-5, where the rear suspension willingly takes on Uphil obstacles without getting stuck. Although I succumb to exhaustion in the midday heat on this day, I don't have to concentrate as much on line choice on the Cervélo. It is also the only one of the three test bikes that has a classic bottle cage mount on both the seat tube and down tube, making hydration particularly uncomplicated. However, just like the competition, only a small bottle fits in the second holder.

How the Cervélo Down-Country Fully performs on the marathon trails

The strengths of the Cervélo ZFS-5 are distributed more in favour of downhill performance in our test trim. The grip of the Maxxis Rekon tyres is much more generous compared to the Rekon Race on the Mondraker and even more so compared to the Continental Race King on the Storck. The Cervélo is the only candidate to use Sram Level Stealth brakes with four pistons. Unfortunately, the additional power is of little value in racing practice. On the long, steep trail descent from the Türlwandhütte, the riders in front of me are so constantly on the brakes that I too am trapped in continuous braking mode. Overtaking? Unthinkable. The result? Cramped brake fingers and red-hot discs. There is no clear advantage over the old Sram Level on the Storck or the new Level Stealth with two pistons on the Mondraker in marathon use.

The suspension of the Cervélo ZFS-5 works confidently, taking on everything the marathon trails have to offer, but is no comfort miracle. The feedback from the Flex-Pivot rear suspension indicates that the fully was developed for fast cross-country racers. The Canadian is rather high in its suspension travel and is really fun with an active, fast XC-style riding style. The uncomplicated handling also matches this. Neither too long nor too short, I am wonderfully centred in the bike and only need a little effort to make the Cervélo follow my directional instructions. The telescopic dropper post and the saddle with a slightly shorter nose than on the Storck and Mondraker create a lot of freedom of movement over the top tube. The short stem and wide handlebars make the ZFS-5 easy to control even when your pulse is pounding.

At the Alpentour in Schladming, it is a tradition that the last descent of the day takes place on a track in the local bike park. Compared to other race bikes, the handling of the Cervélo ZFS-5 is first class here. Although I barely have an ounce of body tension left, I push the bike over the table jumps and through the crushed sand berms with ease. However, the hundreds of braking bumps are pure torture for my battered body. The stiff suspension, the thin silicone grips on thick aluminium handlebars... Comfort is different. Finally, the bike park descent spits me directly under the finish arch and I am relieved. With the Cervélo on the energy-sapping queen stage, I achieve my worst result of the day: 39th place in the Sport Men III class.

The Cervélo ZFS-5 in the BIKE test: data and points

• Front suspension travel: 120 mm
• Rear suspension travel: 120 mm
• Frame material: Carbon
• Wheel size: 29 inch
• Area of application: Down Country / Cross Country / Marathon
• Price: 6799 Euro >> e.g. available here at a reduced price
• Available from: Specialist retailers
• Guarantee: for life

Equipment

• Fork: Rockshox SID Select+
• Shock absorber: Rockshox SIDLuxe Select+
• Gear system: Sram GX Eagle AXS Transmission, 1 x 12
• Gear ratio / bandwidth: 32; 10-52 / 520%
• Brakes: Sram Level Bronze four-piston Stealth, 180 / 160 mm
• Telescopic support/stroke: One Up V2 / 180 mm
• Wheels: Race Face Arc27 Offset
• Tyres: Maxxis Rekon 3C Maxxterra Exo TR, 29 x 2.4"

Measured values

• Total weight: 12 kg (without pedals)
• Frame weight: 1965 g (without shock absorber)
• Weight damper: 268 g
• Weight of wheels: 4559 g
• Impeller inertia: 3478 kg x cm²

Grading

Driving behaviour (65 %): 2.7

• Uphill riding behaviour: 2.50
• Uphill efficiency chassis: 4.00
• Downhill riding behaviour: 2.00
• Downhill suspension: 2.25

Laboratory (10 %): 2.7

• Weight: 2.75
• Wheel acceleration: 2.50

Equipment (25 %): 1.7

• Equipment quality: 2.18
• Usability/added value: 3.75
• Transport volume bottle cage: 1.25
• Saddle retractability: 0.50
• Quality/processing: 1.00

Final grade: 2.2

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Conclusion from BIKE Test editor Jan Timmermann

With its lightweight chassis, a rock-solid equipment package and uncomplicated handling, the Cervélo ZFS-5 120 GX AXS is an attractive bike for sporty riders who prefer to stay off the beaten track both uphill and downhill. In marathon use, the high wheel weight and the bobbing suspension put the brakes on ambitions. More of a versatile, fast touring bike than an uncompromisingly efficient racing bike. Racers are better off choosing the ZFS-5 100.

Pro

• Balanced handling and plenty of tele-stroke for fun on the descent
• High touring expertise
• High tyre grip
• Light frame weight

Contra

• Sluggish on tarmac and on flat terrain
• Suspension not fully lockable, no handlebar remote
• little comfort on rough downhills