Bike Fitting

Podcast Version
​(With NotebookLM)

Buying and setting up the right bike, in the right way:
​A Comprehensive Guide

Buying and setting up your bike correctly is crucial for comfort, efficiency, and injury prevention. Whether you ride a road bike or a triathlon bike, following these steps will help you achieve a better fit. Here’s a step-by-step guide inspired by professional bike mechanics and bike fitters.

Purchasing Bike and Shoes

Some elements of your bike can’t just easily be adjusted. These are things you need to consider when you purchase your bike:

• The size of the frame will depend on your height, as well as the sport and bike type you are looking for. The frames size defines the top tube length, stack, seat tube length and reach.
• Different brands also have slightly different ratios and angles of their frames, so sizes might not coincide with other brands, if you are looking to switch to a new model.
• Triathlon bikes typically have a smaller frame than road bikes for a given height, as they are more aggressively tuned.
• Also consider the width of the handlebars as these should be based on your shoulder width.

Most brands have clear guidelines for sizing based on average body types. If you are in the middle of those categories, there should be not much to worry about. However, if you tend to cross different size patterns, you might want to try them out before purchasing, if possible. One option could be to rent for a day.  Also, the frame size depends on the type of rider you are, whether you are looking for comfort or competitiveness.

Although bikes are considered key, the shoe size and width are critical for defining your comfort too. People with wider feet, often struggle with pain over longer races, this leads to loss of pedal efficiency or a more difficult transition to running.

​Draw your foot length and width on a piece of cardboard and compare it with your insole. If there is a significant difference (5-7mm), you might want to consider a change in size or brand.

DIY Setup

When buying a new bike, we always recommend asking for a basic manual setup by the bike store mechanic, this is for ease of use and the ability to comfortably bike immediately. How you go from there is up to you, your budget and whether you are a competitive age grouper, or just enjoy the rides and the sport. If you buy your bike online, or want to keep finetuning your setup, below are initial DIY guidelines you can start with, but also consider a professional bike fitting for optimal performance.

There is a logic to the madness of bike fitting: from the feet to the knees, hip, shoulders and grip, setting up the cleats, saddle and handlebars.

Cleats: an important part of your setup is the position of your cleats as this is really the connection between you and your bike. If this is not optimal, it does not matter how strong you are or how light your bike is, you will lose speed.

• The simplest way to see if the cleats are positioned correctly is to mark on the outside of the shoe, the boney part at the base of your little toe (fifth metatarsal head). This is also the widest part to the foot.
• Transfer this mark to the sole of the shoe. Most cleats have a notch indicating the center of the pedal axle. Align this notch just in front of your mark.
• Keep it basic! Leave the rotation or lateral movement of the cleats to the professionals

Saddle: The saddle might be the most important part of your comfort on the bike as it carries your weight, affecting the split to your handlebars and driving your pedals. IF your saddle is too high, your hips will rock as you pedal. If the saddle is too low, you put extra pressure on your thigh muscles and create less efficient propulsion.

• Height:
  • You can start with a more formulaic approach to 0.883x your inside leg (Lemond Method).
    • To find your inside leg length, the best bet is to stand without shoes facing a wall and push a book firmly up between your legs until it rests hard against your seat bones. Make sure the edge of the book is flat against the wall and mark the position of the top of the book on the wall with a pencil. Then just measure the height of the pencil mark off the floor. It’s worth repeating a few times to make sure that you’ve measured correctly.
    • Multiply that number by 0.883 to find your saddle height as the distance between the center of the crank axle and the top of the saddle at its midline, following the line of the seat post.
  • You can check the feeling of the saddle by placing your heel on the pedal at the bottom of the stroke. The knee should then be fully extended.
  • As of this position you can gradually adjust and finetune. Professionals like Jan Frodeno recommend frequent small adjustments rather than major changes. This helps your body adapt gradually, reducing the risk of injury.

• Setback:
  • The setback defines the optimal activation and balance of hamstrings and quads. Ideally your knee should be right above your pedal axel or cleat connection when in the most forward position (3 o’clock)
  • Have somebody help you or film yourself from the side.

• Tilt:
  • Always start with a horizontal position and adjust up or down based on the saddle type (long versus short nose), saddle width, the experienced pressure (non-cutout versus cutout) and your level of comfort and sought after competitiveness.

​​Handlebars: The position of the road bike handlebars will affect the angle of your upper body, strain on the shoulders and pressure on your handlebars, affecting comfort on longer rides.

• Reach: Make sure you can reach the handlebars with relaxed shoulders and slightly bent elbows (15 degrees). Your shoulders should be at a 90-degree angle with your torso.
• Drop (Height): You can adjust the height by adding or removing spacers under the stem, so your back is about 45 degrees from horizontal, between 

Aerobars: For triathletes the aerobars might be more important than the handlebars. Don’t forget that for triathletes the position is slightly less aero and aggressive than for pure time trial performance. This extra comfort improves the transition to running. It is up to the athlete to determine the right mix of aero and comfort for optimal total performance.

• Stack height is the height from the bottom of the handlebars to the top of the aero bars. This is largely influenced by the length of your upper arms and the aggressive angle of your upper body. Typically, this is between 5 – 10 cm.
• Aero Bar Angle: the angle depends on the brand, but more recently high angles have been seen in the professional scene.
• Aero Bar Spacing is the space between your two aerobars and is mainly affected by shoulder width, shoulder mobility and comfort. Typically, they are between 3 and 12cm.
• Aero Bar Length is the distance from the front of your handlebars to the end of your aerobars and depends on the length of your forearms. Typically, they are below 30cm.

Remember that if you are adding setup aerobars on a road bike, your saddle height and setback might have to be adjusted to be comfortable. Ideally, the angle between your shoulders and upper arm should be 85-90 degrees (maximum 2cm behind the elbows) when resting your elbows in the aerobar pads.

Note that the setup of handlebars and aero bars can significantly depend on your core strength, allowing you to have a more competitive position.

Professional setup

Of course it is always better to have a professional setup your bike, but this can set you back a few hundred euros or dollars. There are a lot of options, so we will give you some guidance below:
​

1. Retül Fit is probably the most well known and utilizes advanced 3D motion capture technology to analyze rider's movements dynamically and in real-time. It provides a comprehensive and detailed fitting report that helps in optimizing bike fit. The system is very precise, leading to improved rider comfort and performance, but can take a lot of time to execute the protocol and is quite expensive.
2. BG Fit (Body Geometry Fit) uses a more holistic approach to bike fitting by incorporating a physical assessment of the rider’s flexibility, strength, and overall physical condition. It may not provide as much quantitative data as some other systems, relying more on the fitter’s expertise and experience.
3. Guru Fit System is fully automated, allowing for easy and quick adjustments during the fitting process. It is highly customizable and user-friendly, making it accessible for both fitters and riders. It is quite expensive and limited to specific fit bikes, which might not cover all rider needs.
4. F.I.S.T. (Fit Institute Slow Twitch) is specifically designed for triathletes and time-trialists, focusing on achieving optimal aerodynamic positioning. It provides detailed protocols and guidelines that help in achieving a precise and effective fit for these specific disciplines. However, because the system is so specialized it is not for most general road cyclists or mountain bikers. 

Conclusion

Setting up your bike at home can be a rewarding process that enhances your cycling experience. While professional bike fitting is always recommended for precision, following these steps can get you started on the right track. Remember, the key is to make small adjustments and listen to your body’s feedback.

For more in-depth tips and personalized advice, don't hesitate to consult with your coach or a professional bike fitter.

Don’t forget. It is the small daily steps that turn into positive habits, patterns, and beliefs ingrained in body and mind. Enjoy the journey!

BONUS TIPS COACH GLENN:

When starting to compete in sprint and olympic distance triathlons, a basic setup of your road bike by the mechanic at the bike store might be the right way to go. The time on the bike is shorter and does not involve aerobars. However, as soon as you evolve to half and full distance triathlons, I highly recommend a professional fitting. The expense is worth it and will make your life so much more comfortable, not only on the bike in training and racing, but also off the bike and into the run.

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