Improving a bike – body relationship involves developing a deep understanding of all three aspects: the bike, the body, and how they interact and relate.
Let’s focus on the body. Whether it is a pre-purchase sizing or an in-depth bike fit, having a structured approach to assessing the rider’s body can save you time and help marshal your thoughts to guide you to effective recommendations.
The 4 perspectives of body assessment are:
4. Pre Existing Conditions
Each cyclist is different in many ways, and without a structured approach to assessment, it is easy to overlook a significant contributor to an appropriate bike fit. To build up a holistic understanding of our bike fitting client, it helps to consider the parts that make up the whole from a number of different perspectives:
The skeletal layer is the framework on which all other layers are added and function. It provides a baseline of information as to what is possible and viable, or not. It’s more than inseam or height, it is about both absolute and relative proportions. Long legs, short legs? Long arms? Short arms? Sit bone width? Shoulder width? Skeletal measurement information provides valuable data to help with recommending a bike size and to solve fit problems.
How to assess skeletal measurements?
The Fit Kit System measuring devices provide reliable data quickly and simply. Some other companies also supply manual measurement tools, as well as digital tools based on body scanning or 3D cameras, such as that in the Guru system. The advantage of a physical, manual method is that you (or the rider) are physically locating the measurement points, the rider is actively engaged in the process, and it can lead to additional information and insights.
Skeletal, anatomical measurement information defines what relationship between the bike contact points is biomechanically viable based on that person’s structure. Frame size and geometry, seat height, reach and drop are all going to be defined in the first instance by what is skeletally achievable.
What’s achievable may not be desirable or optimal, so let’s add another perspective:
The muscles (and associated connective tissue) move the bones of the skeleton. A rider with well conditioned muscles, a good range of motion and highly functional movement patterns can move the skeleton into sustainable riding positions that are not an option for a rider with weaker muscles, tightness or imbalance.
How to assess muscles?
There are a number of approaches to gaining information about the person’s muscles as relevant to riding. From quick and simple to longer and involved assessments, the method you use will depend on the depth of information you need and your training and experience in applying these:
• Basic flexibility assessment
• Posture and gait assessment
• Passive range of motion tests
• Active mobility and stability tests
• Functional Movement Screen
• On bike observation, including posture, muscle engagement, joint angles
• Asking questions about soft tissue aches and pains
The strength and flexibility of the muscles and associated connective tissue (tendons and ligaments) are going to determine the effective movement of the skeleton.
Take the same skeleton. Apply a different muscle assessment, for example, tighter hamstrings. This may result in a lower saddle height, and shorter reach and drop.
The role of the muscles is also going to change by how adapted the person is to cycling.
Adaptation modifies the muscle functioning and fatigue resistance.
As bike fitters we generally want to adjust the bike rather than force the body to adapt. However putting a body on a bike requires the body to make some adaptations. Adaptation is going to be influenced by:
• Time on the bike (cycling history and experience)
• Training, exertion
• Bike type and riding style
• Participation level / Event type
How to assess adaptation?
Ask questions to gain information. Questions like:
• How long have you been riding, how often, how far, how hard?
• What type of bike do you ride or will be riding?
• Have you changed out any equipment (shoes, stem, saddle, bike)
• Have you made any adjustments to your bike set up recently?
Someone who is new to cycling, or returning after a long period off the bike, or changing from say a mountain bike to a road bike, is going to be less adapted than someone with a long history on the same style of bike.
A novice is likely to be happier with a more relaxed riding position than an experienced rider, as their body has not adapted to the position and muscular requirements of cycling. A more experienced rider will probably prefer a higher seat height and a longer and lower reach.
A highly adapted rider may be resistant, both psychologically and neurologically, to changes in their fit position, requiring graduated change over time.
4/ PRE-EXISTING CONDITIONS
Take all of the above and add a final layer. Body issues and history that are very specific to the individual will often require consideration and accommodation. These are most commonly from injuries or surgery. The event may have been recent, but sometimes so long ago they have forgotten about it. Examples include broken bones, sprained ankles, fractured vertebrae, whiplash, leg length differences, disc degeneration, hip replacement.
How to assess pre-existing conditions?
Ask questions in a pre purchase or pre-fit interview, like:
• Have you had any accidents, injuries or surgeries that would affect your position and comfort on a bike?
• Do you have any spinal problems? Repetitive stress injuries?
• Are you seeing a medical professional or therapist for any sports related issues?
It’s not uncommon for a rider to not volunteer or forget to mention something of relevance. If you observe an odd movement pattern or asymmetry when they are on a bike, ask again. Are you sure you have never broken a bone? Suddenly the person might remember they broke an arm as a 12 year old, or tore an ACL skiing.
Is a condition going to affect their position, and if so how? What has to be done to accommodate that?
This is going to depend on the situation, but may have implications for cleat shimming or wedging, seat height, reach and drop, the placement of the controls.
The body is an incredibly complex unit, and riding a bike adds complexity. Having a simple structured approach to building up information about a rider’s body is a useful tool to navigate through the complexity. It helps in creating a strong and respectful relationship with the cyclist, and to offer fact based observations and recommendations that will benefit their bike choice, fit position and riding experience. It’s an intrinsic part of the Fit Kit System and can be a 5 – 10 minute process for a pre purchase sizing or a 45 minute process in a detailed bike fit session.