Aero & All-Round Race Bikes

This category covers Cervélo's top-tier race bikes designed for speed, low weight, and responsive handling. Sizing is consistent across their modern aero, all-rounder, and climbing platforms. These bikes feature aggressive, long, and low geometry intended for riders with good flexibility who prioritize outright speed.

Endurance Road Bikes

Designed for long days and imperfect roads, these bikes offer a more relaxed, stable geometry for all-day comfort. The sizing below is based on the current Caledonia models, which feature a higher front end (stack) and more stable handling than the pure race bikes.

Time Trial & Triathlon Bikes

Cervélo's legendary triathlon and time trial bikes are optimized for aerodynamics. Fit is extremely personal and depends heavily on the rider's target discipline (e.g., UCI-legal TT vs. long-course triathlon) and flexibility. These charts are a starting point for a mandatory professional bike fit.

P5 (Elite Time Trial)

P-Series & PX-Series (Triathlon)

Off-Road Bikes

This category includes Cervélo's gravel, cyclocross, and cross-country mountain bikes, designed for performance on varied and challenging terrain.

Gravel & Cyclocross

Mountain Bikes

Beyond the Charts: A Deep Dive into Cervélo Fit Philosophy

While the height charts provide a solid foundation, understanding the concepts behind Cervélo's sizing can empower you to make a more nuanced choice. A perfect fit is a blend of science and personal preference, and knowing the language of bike geometry is key. This section will guide you through measuring yourself accurately, understanding critical geometry terms, and appreciating the specific fit characteristics of Cervélo's core models.

How to Accurately Measure Yourself at Home

To get the best results from any size chart, you need accurate data. Your two most important measurements are overall height and inseam. For these, you'll need a tape measure, a wall, and a hardcover book.

• Measuring Height: Stand with your shoes off, heels and back flat against a wall. Look straight ahead. Place a hardcover book flat on your head, pressing it back against the wall to ensure it's level. Mark the spot on the wall under the book. Measure from the floor to the mark.
• Measuring Inseam: This is the single most critical measurement for bike fit. Stand with your back against the wall, feet about 15cm (6 inches) apart. Place a medium-sized hardcover book between your legs and pull it up firmly into your crotch, simulating the pressure of a saddle. Make sure the book is level with the floor. Measure from the top edge of the book to the floor. This measurement determines your standover height and is a better indicator of leg length than your trouser size.
• Considering Your 'Ape Index': If you find yourself right on the cusp between two sizes, your body proportions can be a tie-breaker. Your 'ape index' is your arm span minus your height. If you have a positive index (your arm span is greater than your height), you have relatively long arms and may be more comfortable on the larger size. If you have a negative index, your shorter reach might be better suited to the smaller size.

Demystifying Geometry: The Importance of Stack & Reach

Modern bike sizing has moved beyond simple seat tube lengths. The two most important metrics on any geometry chart today are Stack and Reach. Understanding them will tell you almost everything you need to know about how a bike will feel.

• Stack: This is the vertical distance from the center of the bottom bracket (where the cranks spin) to the top of the head tube (where the handlebars attach). Think of it as the handlebar height. A higher stack number means a more upright, relaxed riding position, which is great for comfort and endurance (e.g., Caledonia). A lower stack number means a lower, more aggressive, and aerodynamic position (e.g., S5).
• Reach: This is the horizontal distance from the center of the bottom bracket to the top of the head tube. Think of it as the length of the cockpit when you're standing up to pedal. A longer reach means a more stretched-out, stable feel, while a shorter reach results in a more upright, nimble-feeling bike.

Cervélo's Model-Specific Geometries: A Comparative Look

Not all size 54 frames are created equal. Cervélo tailors the geometry of each model for its intended purpose, which results in a vastly different ride feel, even for the same size rider.

• S5 (Aero Race): The S5 is built for one thing: cheating the wind. It has the lowest stack and longest reach in Cervélo's road lineup. This forces the rider into a powerful, flat-backed position. Sizing for an S5 is about finding the most aggressive position you can comfortably hold. Its unique V-stem also limits adjustability, making an initial professional fit even more critical.
• Soloist (All-Round Race): The Soloist is the versatile workhorse. Its geometry sits between the S5 and R5. It's still an aggressive race fit, but with a slightly higher stack than the S5, offering a touch more comfort without sacrificing much aerodynamic advantage. It's a perfect choice for racers who want one bike for all courses.
• R5 (Climbing/All-Round Race): While still a pure race bike, the R5 prioritizes handling and comfort on long climbs. Compared to the S5, it has a noticeably higher stack and slightly shorter reach. This opens up the rider's chest for easier breathing on climbs and provides a less demanding position for long mountain stages.
• Caledonia (Endurance): The Caledonia is the comfort-oriented outlier. It has a significantly higher stack and shorter reach than any of the race bikes. This creates a much more upright riding position that relieves pressure on the back, neck, and shoulders. Furthermore, it has a longer wheelbase and slacker head tube angle, which makes it incredibly stable and confidence-inspiring on rough roads and long descents.
• Áspero (Gravel Race): The Áspero is designed for high-speed gravel racing. Its geometry is aggressive for a gravel bike, with a focus on stability over rough surfaces at speed. A key feature is the "Trail Mixer" flip chip in the fork, which allows you to adjust the bike's handling to compensate for different wheel and tyre sizes, ensuring consistent responsiveness.

Fine-Tuning Your Fit: Post-Purchase Adjustments

Once you've chosen your frame size, the process isn't over. Dialing in your contact points is what turns a correct size into a perfect fit. These are the key adjustments you and your bike fitter will make.

• Saddle Height: This is the most fundamental adjustment. The goal is to have a slight bend in your knee (around 25-30 degrees) at the bottom of the pedal stroke. Too high, and you'll rock your hips; too low, and you'll lose power and risk knee pain.
• Saddle Fore/Aft Position: Sliding your saddle forwards or backwards on its rails affects your weight distribution and relationship to the pedals. A common starting point is the KOPS (Knee Over Pedal Spindle) method, where a plumb line from the front of your kneecap drops through the center of the pedal axle when your cranks are horizontal.
• Stem Length and Angle: The stem has a huge impact on reach and handling. A longer stem will stretch you out more, while a shorter stem provides a more upright position and quicker steering. Most Cervélo race bikes come with a standard -6 degree stem, but swapping to a different length or angle is a common fit adjustment.
• Handlebar Width and Rotation: Road handlebar width should generally match the width of your shoulders to promote open breathing and stable handling. Rotating the bars slightly up or down can change the angle of your wrists on the hoods and your position in the drops.

Cervélo Sizing FAQ

Why is a professional bike fit so important for a Cervélo?

Cervélo frames are engineered with specific performance goals. An aero bike like the S5 requires a very different body position than an endurance bike like the Caledonia. A professional fitter uses your body measurements, flexibility, and riding goals to not just select the right size, but also to adjust the stem, handlebars, and saddle for optimal power, comfort, and aerodynamics. This is a crucial step for getting the most out of your investment and preventing injury. A fitter can see things about your posture and pedal stroke that you can't, ensuring your high-performance machine is perfectly integrated with your body.

I'm between sizes. What's the deciding factor?

If you're between two sizes, consider your flexibility, riding style, and body proportions (ape index). A more flexible rider aiming for a low, aggressive "pro" position might opt for the smaller size and use a longer stem. A rider prioritizing comfort or with less flexibility may prefer the larger size for its inherently higher stack, which creates a slightly more upright posture. When in doubt, it is often easier to make a smaller frame fit "larger" with a longer stem than it is to make a large frame fit "smaller," as reducing reach on a large frame can compromise handling.

How does the geometry of an S5 differ from a Caledonia?

The primary difference is in the bike's "Stack" and "Reach" measurements, which define its intended purpose. The S5 (Aero Race) has a very low Stack and long Reach, stretching the rider out into a flat, powerful, aerodynamic position. The Caledonia (Endurance) has a much higher Stack and shorter Reach. In a size 56, for example, the Caledonia's stack is about 30mm taller than the S5's. This allows for a more upright, comfortable position that reduces strain on the back, shoulders, and neck over long distances, making it ideal for gran fondos and riding on less-than-perfect roads.

Do Cervélo bikes generally run large or small?

This is a common question, but the answer is nuanced. Cervélo's race bikes (S, R, and Soloist series) are designed with a "long and low" geometry that is true to their racing heritage. Compared to some endurance-focused brands, a Cervélo of the same nominal size (e.g., a 56cm) might feel longer and more aggressive. They don't necessarily "run large"; rather, they are sized for a performance-oriented riding position. The Caledonia is the exception, with its geometry being more in line with other major brands' endurance platforms. It is always best to compare the specific Stack and Reach numbers rather than relying on the frame size alone.

How does the unique V-Stem on the S5 affect sizing and adjustments?

The iconic V-Stem on the new Cervélo S5 is a critical part of its aerodynamic system, but it does have fit implications. Unlike a standard stem, its height is only adjustable with proprietary spacers in 5mm increments, and making adjustments is more labor-intensive. The available stem "lengths" are also fixed (80, 90, 100, 110, 120, 130mm). This reduced adjustability means it is extremely important to determine your ideal position during a pre-purchase bike fit, as making significant changes later can be complex and expensive. The size you choose must be one where your ideal handlebar position falls within the V-stem's adjustment range.

I have back pain on my current bike. Will a different size Cervélo fix it?

It might, but the frame size is only one part of the equation. Back pain is often caused by a position that is too long or too low, forcing your spine into excessive flexion. If you are on a race bike like an R5 or S5, switching to an endurance model like a Caledonia in the same size could provide significant relief due to its much higher stack height, allowing for a more upright posture. However, back pain can also be caused by incorrect saddle height, saddle tilt, or even a lack of core strength. The best course of action is to consult a professional bike fitter who can diagnose the root cause of your pain and recommend the right bike and setup for your body.

Can I use my measurements from another brand (e.g., Trek, Specialized) to choose a Cervélo size?

You can use them as a starting point, but you should never assume a size 56 from one brand is identical to a size 56 from another. The most reliable way to compare is to ignore the size sticker and look at the geometry charts, specifically the Stack and Reach numbers. Find the Stack and Reach of your current, well-fitting bike. Then, look at the Cervélo geometry charts to find the size that most closely matches those numbers. This data-driven approach removes guesswork and accounts for the fact that every manufacturer has a unique fit philosophy for their frames.