FIRST LOOK: Cervelo ZFS-5 120 XO AXS mountain bike
Cervelo have jumped into the mountain bike arena, which is no surprise with Paris 2024 on the horizon.
Some say XC is dead, but those people probablty haven't stood 3 deep on the tape at a World Cup, with ear plugs in to help manage the noise. If 2023 taught us anything, it showed that global mountain bike coverage is a big thing for the growth of mountain biking, and some disciplines suit it better than others. RIP EWS EDR.
Last year there was plenty of noise about Cervelo releasing a mountain bike for their road professionals who were racing World Cups with an eye on qualifying for the Paris 2024 Olympics. Given few other cycling brands epitomise racing like Cervelo, it should be no surprise that the ZFS is targeted at cross-country and marathon use. Don't expect to see a trail bike or party hardtail from this crew anytime soon.
Cervelo offer the ZFS in 100mm and 120mm variants, with changes to the build kit depending on the travel. You can also buy a frame set for $5800 – that's far from cheap but about right when you look at other premium full-carbon cross-country frame sets on the market.
The Cervelo ZFS-5 at a glance
The Cervelo ZFS uses a flexstay swing arm and toptube slung rocker, providing quite an open main triangle – enough so there are bosses for bottle cages on both the downtube and seat tube.
The frame is full carbon, with a threaded bottom bracket shell and a mount for the rear brake, a pleasant move away from a flat mount, meaning you can fit 4-piston brakes, like our test bike has.
The routing is internal, and it does come in through the headset. The cover is very neat, with plugs for ports not being used, which should go someway in actually keeping water out of the headset. This is something many bikes using headset cable/hose routing suffer with.
The main pivot is taking up about as much width as possible, to deliver precision suspension action and hopefully a stiff platform when out of the saddle.
Geometry is modern XC – to a point. On our large 120mm test bike the reach is a modest 457mm, which is nearly 30mm shorter than something like a Norco Revolver or Specialized Epic. But it is very close to a Factor Lando XC – funnily enough another recent XC bike release from a road bike company. Reach isn't everything, and if you quizzed World Cup racers they would probably be asking for low weight, high stiffness, agility, low bar height and a forward pedalling position.
The right geometry for any bike is about finding the right mix, and the reach is paired with 1 66.6 degree head angle on the 120mm travel build, along with a 114mm head tube on the large. The seat tube angle is 75 degrees on large, with a 437mm chain stay length. The stays get a bit longer on larger sizes, and the seat angle changes minor amounts as well.
The result is a bike that has the rider in a very centred position. With a 44mm offset fork and a moderate seat angle, the shorter reach should keep weight on the front wheel enough when climbing to prevent any wander. And that slack head angle (for XC) keeps an even hand on the tiller in janky chutes and webs of muddy, wet roots.
Cervelo ZFS-5 models
Cervelo offer six different models. The 100mm variants are available in build kits with SRAM XX SL AXS, GX AXS or GX Eagle. They have remote lock out RockShox suspension, wheels with 27mm or 28mm internal widths, 2.4" tyres, fixed posts and 4-piston brakes.
The three 120mm models come in SRAM XO AXS (on test here), GX AXS or GX Eagle. Our test bike is the only model with Fox suspension, via a Fox 34 SC Performance Elite fork and Fox Float shock. These are non-remote, with a 3 position fork and 2 position shock. Wheels are the same with 27mm or 28mm internal widths, tyres are chonkier models but still 2.4", and brake remain at 4-piston – but there are dropper posts.
The cockpit also moves to a flat stem and riser bar, compared to a 6 degree with low rise on the 100mm options. Pricing starts at $990 and runs up to $17000. Our test bike is $12000. This is no small change but it compares well with the Specialized Epic or Epic EVO range, and is potentially better value for some models – depending on what spec you are looking at.
First rides on the Cervelo ZFS-5 120 XO AXS
120mm XC bikes are my jam, there is no doubt about it. Even back in 2007 I was riding and racing a high end Scott Spark, with about 120mm of travel in the back end, albeit 100mm of Fox Terralogic fork travel. It was the style at the time.
A lot of manufacturers are offering bikes in 100mm and 120mm variants, or 100 and 120/115mm – it just depends on the frame design. Smaller riders may not want the extra travel and bar height, and riders who primarily have smoother hard pack trails may also prefer less travel. Personally, I see few disadvantages with a 120mm setup. I'm not flexible enough to need a lower bar height than what is possible by moving spacers, and the extra travel can offer a bit more all-round versatility.
Compared to my own Factor Lando XC, the Cervelo ZFS-5 has an all over neater look thanks to the SRAM Transmission group set and wireless dropper. It is quiter with better internal routing, and is more upright given the flat stem and riser bar.
On my first ride, I have been really impressed with how well it pedals when the shock is open. I've only ridden some trails on it but it feels really stable in the midstroke – but quite XC. My preference is for remote lock out, even on a 120mm setup – but I don't think I would reach for the lockout on this bike unless I was on a long road climb.
The position is very centred, and certainly one that feels like it is ready to change direction at a moments notice. It is shorter overall than any of my previous bikes, but that means it does stick to the ground around climbing switchbacks, and pop around on the trail with ease.
Kudos to Cervelo for stocking an excellent set of wheels on the Cervelo ZFS. Yes, you should expect that on a bike for $12000, but it isn't a given. The Reserve 28mm wheels on DT Swiss 350 hubs are a sweet combination for ease of servicing and performance. The stock Maxxis Rekon 2.4" tyres are 60tpi which are always Tonka Tuff – but there are a lot of gains in this area if you're after some race spec tuning. We've got 10 XC treads on test right now, if that sparks your interest.
Cervelo have delivered what feels to be a balanced platform targeted at racers. With some XC bikes being stretched out and overbuilt to edge into downcountry builds, don't expect the Cervelo to fall into that category. Few brands epitomise the saying 'life is a race' better than Cervelo, and I truly expect this bike to be a rocketship. And for a bike being built for the World Cup with an Olympics coming up and a longer World Cup calendar than in previous years – that is exactly as it should be. Stay tuned for my full review in a coming issue.