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Cervelo P5X: A Real-Life Tron Bike That’s Crazy but Also… Practical?

This Cervelo P5X looks like a bike from the future, but it was actually designed nearly 10 years ago. Despite the wild looks, it was made to make riding and racing simpler for serious triathletes. Let's dive deeper into this bike's clever, untraditional design.

Written by: Bruce Lin

Published on:

Posted in:Bikes

I used to draw a lot of bikes when I was a kid and if my art skills could capture what my 8-year-old self imagined the ultimate bike to look like, it probably would have looked like this crazy Cervelo P5X. 

I’m no triathlete, so I generally don’t take much interest in triathlon bikes. But with a wild frame design, a tricked out build, and eye-searing colors, this bike simply can’t be ignored. So why does it look the way it does? 

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Why the Crazy Frame Shape? 

Cervelo p5X FrameSince the invention of the modern bicycle, it has used a traditional diamond-shaped frame. It makes a lot of sense because a diamond frame is composed of two triangles — one of the strongest shapes in nature.

When building a bike frame from steel tubes, it is the simplest shape that provides the rigidity needed for cycling without excess weight. The arrival of carbon fiber, however, gave bike builders more freedom to experiment with frame design.  

Lotus Sport 110

This 1995 Lotus Sport 110 is one of the OG non-traditional frames. It's one of the stars of our vintage museum

One of the most famous bikes to eschew the traditional diamond shape might be the Lotus Sport 108 & 110. This bikes used a radical carbon “Z-shaped” frame designed to maximize aerodynamic efficiency. The Lotus was famously ridden by Chris Boardman, who won gold and set a new world record in the 4000m pursuit at the 1992 Olympics and set a new World Hour Record at 56.375 km before UCI rule changes nullified the result. 


Ultimately, road racing bikes today still use the traditional diamond shape because of rules set by the UCI, cycling’s governing body. Radical aero designs like the Lotus Sport have been outlawed and frame shapes and dimensions are bound by strict guidelines. 

Kristian Blummenfelt CadexOlympic triathlon gold medalist and Ironman world champ Kristian Blummenfelt races a non-traditional Cadex frame. Photo: Glen Murray / Red Bull Content Pool

There is one place, however, where UCI rules don’t matter — triathlon. Triathlon has its own governing body and bike design is more like the Wild West with everyone just trying to build the fastest bike possible. Around 10 years ago, triathlon bikes started utilizing non-traditional frame shapes started gaining popularity. 

Ventum Dimon Tri bikeThe Ventum One (left) and Dimond Brilliant (right).

Ventum and Dimond are perhaps two of the most well-known brands specializing in non-traditional triathlon frames, but they are far from the biggest brands in triathlon. Cervelo, in comparison, is a giant. It’s our top TT/Tri brand, and it consistently leads bike counts at the biggest triathlon races. 

The original 1995 Cervelo Barrachi concept came 20 years before the P5X.

Cervelo’s entry into the non-traditional Tri bike arena, the P5X, was first released in 2016. It actually looks quite similar to the original Barrachi concept bike that Cervelo founders Phil White and Gérard Vroomen made in 1995. Like the Barrachi, the P5X was designed to have unbeatable aerodynamics without sacrificing weight or stiffness. To accomplish this, Cervelo partnered with HED to build a full carbon monocoque frame in Minnesota as one complete piece. 

Cervélo engineers also spent an estimated 180 hours in the wind tunnel. In their own testing, the P5X tested faster than Cervelo’s flagship P5 time trial bike at nearly every yaw angle. This was especially true with outfitted with all the extra gear riders carry for long-course triathlon (i.e. Ironman) events (more on that in a bit). 

The frame was also one of the earliest TT/Tri bikes to be designed around disc brakes, which improves safety (TT/Tri bikes are notoriously bad on the brakes) without sacrificing aerodynamics. This was a bold move because disc brakes were far from standard in 2016, and some Ironman events at the time even banned them. 

Zipp Softride

Some older riders might note that the P5X looks like the “beam” bikes (like Softride) of the late '90s and early '00s. Unlike those beam-style bikes though, the floating seatpost/top tube isn’t designed to provide extra compliance. Stiffness and efficiency were key design goals, and the seatpost/top tube is so stiff that it deflects less than 1 mm under a 75 kg rider. 

To me, when placed side-by-side with similar offerings from Ventum and Dimond, it just looks a cut above. The sculpted monocoque frame has been meticulously designed specifically for the specific demands of triathlon, and it literally looks like a bike from the future. 

The P5X Went Beyond Aero 

Cervelo P5XJust like with the Lotus Sport and Barrachi, aerodynamics was a big focus of the P5X’s frame design. But it wasn’t the ONLY focus. Cervelo began developing the P5X three years before it was released, and it started by studying racers at major events. 

Cervelo engineers took thousands of photos of riders on course to see how they set their bikes up with aftermarket accessories and talked to them one-on-one about their needs and wants. 

This led to 7 key design goals for the P5X (in order of importance): 

  1. Modular, integrated storage that’s easy to access
  2. Compatible with round bottles
  3. Easy to fit the athlete to the bike
  4. Easy to adjust the athlete’s position after initial setup
  5. More aero than P5 on race day
  6. Same stiffness as the P5
  7. Easy and safe to pack

Interestingly, aerodynamics is number 5 on this list, while storage and fit were bigger priorities. During its research, Cervelo found that many riders were using third-party components or improvised solutions (like taping gels to the top tube) to carry the supplies needed on the bike. Not only was this inconvenient, it could also negatively affect the aerodynamics of the frame. 

So the P5X placed a lot of focus on ample storage that was easy to access. The bike comes with 3 integrated storage solutions:

  • Smartpak - On the top tube - for nutrition
  • Speedcase - On top of down tube - for extra gear 
  • Stealthbox - Under the down tube - for tools and spares

These three removable storage boxes are neatly integrated into the shape of the frame, and because the frame itself is hollow, there is enough space to carry everything needed for extra-long rides (like a 112-mile Ironman bike leg). There are even thoughtful details like a pill tray in the Smartpak to keep things like salt pills in place and easy to reach.

The frame is also specifically designed to carry regular round water bottles without impacting the aerodynamics. Bottles can be mounted on the top tube, behind the aerobars, on top of the Speedcase, on the down tube itself when the Speedcase is removed, and behind the saddle on an included adjustable mount. 

This makes life easy because round bottles are cheaper and more common. Riders using aero bottles also often need to transfer water into their aero bottles rather than just swapping bottles after a neutral bottle hand up. 

Cervelo P5X ENVE CockpitFinally, the cockpit (and fork) was made by ENVE, and it is designed to be super easy to adjust. The extensions use a wedge system, similar to a seatpost, that provides a huge range of height adjustment just by loosening a single 4mm bolt. No finicky spacers are required.

Cervelo P5X bike bagThe Cervelo P5X packed for travel. Photo: Tri247

The bars have another clever trick up their sleeve. By undoing the 4 bolts in the center, they can actually fold in half. This makes the P5X extremely easy to pack for travel, especially when used with the protective Biknd case which was designed specifically for it. 

With an original retail price of $11,000-15,000, the P5X was certainly a halo bike, but unlike many superbikes, the thoughtful design probably makes it one of the more practical triathlon bikes you could buy. 

Who Should Buy This Thing? 

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At $7,500, this P5X is one of the most expensive Certified Pre-Owned bikes currently at TPC. That’s understandable considering the frame and the super-blingy build. The standout component might be the HED Vanquish RC8 Pro / RCD Pro wheelset which matches the frame’s color scheme. 

Cervelo P5X drivetrainThe disc wheel is driven by a SRAM 1x drivetrain with a Red power meter crank with a 50t aero chainring. The rear derailleur is a wireless SRAM XX1 Eagle AXS mountain bike derailleur upgraded with a CeramicSpeed OSPW system. It shifts on a 9-46t e*Thirteen cassette with SRAM wireless blips. 

One nice feature of this particular frame is that the previous owner left the seatpost uncut. The P5X can be ridden with the seatpost sticking out from the bottom of the top tube, but it’s designed so it can be cut flush for a cleaner look and better aerodynamics. This means any new owner will be able to set this seat post up perfectly. 

Overall, this is probably one of the fastest used triathlon bikes someone could buy. The original aerodynamic claims from Cervelo stated that the P5X should save around 3-7 watts over the standard P5. This equates to around 15 seconds over 40k or around 1 minute during an Ironman. Whether that’s worth $7,500 is up to you and your wallet to decide. It's discontinued now, so it's a rare bike too.

Zwift Concept Z1 Tron bikeLook familiar?

My feeling is that anyone who would actually purchase this bike will be buying more with their heart than their head. Beyond the marginal gains in performance or the rarity, the real reason to own this bike is because it’s cool.   

The first thing I thought of when I saw this bike was Zwift’s Concept Z1 “Tron” bike. I mean, just look at the photos. This P5X seems to glow. But the radical frame shape makes this real-life bike look even crazier than a fake video game bike. When we first saw it, my manager Ellie said, “Dude, WTF.” 

Cervelo P5X Dude WTFThe level of novelty with the Cervelo P5X might be unmatched. I’m probably never going to do a triathlon (I’d need to learn to swim first), but I would love rolling up to a race on this thing. It’s basically triathlete catnip, and for an attention-hungry rider like me, that’s perfect. 

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