By Julie Young Preface: Fitting road, cyclo-cross and mountain bikes follows a similar formula; TT and Triathlon bikes depart from this formula. For this article, we will focus on the road bike.
In part I we outlined the instrumental, investigative process, including the interview and physical assessment that takes place prior to the actual on-bike fit.
On the Bike
Once we have gathered the off-bike information, we can finally jump on to the bike.
One of the most important starting points of the fit, is ensuring the width of the saddle supports the individual’s sit bone width. Often, people purchase saddles because they like the look – which may provide the right saddle one out of ten times. Fit clients will also argue that “I love my saddle, it feels fine.” Yet when we reference the client’s sit bone width to the current saddle, we discover the sit bones rest off the side of the saddle, placing the body weight on the soft tissues rather than on the bones.
Ensuring that the main contact point – the saddle is appropriately fitted to the client, not only ensures that soft tissues remain healthy (blood flow and unobstructed nerves), it also ensures that the bony land marks (sit bones) are squarely established on the saddle, to provide proper upper and lower body alignment.
A couple examples of repercussions of incorrect saddle sizing are
- Often when a saddle is too narrow for sit bone width, the cyclist sits crooked sit on the saddle, resulting in one knee coming in to the top tube, while the other one drifts out.
- Improper support at the saddle, often also results in bearing too much weight on the handlebars.
- Loss of blood flow to soft tissues and nerve damage.
We have three contact points on the bike and need to make sure we disperse the pressure appropriately across those three contact points, and within each contact point avoid peak pressure.
Traditionally the cleat was placed in the fore/aft position so that the first metatarsal lined up with the pedal spindle. Now, we are moving the cleat, as far back as most shoes will allow, placing the foot farther forward. This achieves a few things –
- It reduces the compression and resulting collapse on the metatarsal, thus helping to reduce the innervation of nerves in to the toes.
- Cleats placed forward equates to pedaling with the toes and heavy reliance on the quads. Bringing the cleat back allows us to share the load and better recruit the glutes in the pedal stroke.
- It creates a more rigid lever in the foot and more effective power translation in to the pedals.
We set the rotational aspect of the cleat placement based on how the athlete’s foot naturally hangs. We then ensure that the natural is the rider’s neutral and there is a little float on either side.
We have two fits we offer – optimal and accommodated. The optimal fit places the rider in system-determined neutral range of flexion. For example with the knee extension at the bottom of the pedal stroke – we place the rider in approximately 30 degrees of flexion, knowing that the safe window of knee flexion is 27-37. We recognize that cycling is dynamic and for example, as we climb we may push back on the saddle, reducing the knee flexion, and as we move forward on the saddle, across the flats we increase this flexion. This being the case, when the rider is seated on the saddle, where they spend a majority of their riding time, at either end of this safe, knee-flexion range.
In an accommodated fit, these ranges are modified in order to accommodate an individual’s current pain or restrictions in range of motion. So for example if a fit client comes in with a knee replacement, we might consider moving them slightly farther back than the deemed neutral fore/aft position to help alleviate the femur to patella compression.
Reach - Proof is in the Posture
Once the saddle height and fore/aft have been established, then we dial in the reach. The saddle height and fore/aft has more tightly determined rules in order to protect the knee and optimize muscle recruitment. But the reach is where we can accommodate issues of inflexibility, injury and pain with varying degrees of stem slope and length. But ultimately reach rests on the ability to establish the sit bones, find neutral pelvis and spine and engage with tummy up and in, and maintain that neutral while hinging at the hips to reach the bars. The saddle provides the support, but the trunk and pelvis provide the stability so the arms and hands remain light.
It has been interesting to me to realize, more and more, the absolute importance of posture in the bike fit and optimizing power output. As cyclists we fixate on the legs, but it must start with pelvic and spinal posture. In fitting one of the greatest complaints is lower back pain. In nine out of ten times this is a result of sitting on the bike with a posteriorly tilted pelvis and curved spine. This not only leads to pain and over-use injuries, it greatly inhibits power production from the hips in to the pedals. The key to resolving lower back issues and improving power is finding neutral pelvis and spine, and hinging at the hips to reach the bars.
In part III, we will conclude the series with a discussion on the value-added aspects of the Silver Sage bike fit, including off-bike activation, stability and mobility exercises to improve position and power production, as well as share our insights on maximizing pedaling technique.
If you have questions about bike fitting or are just looking for advice, email us at firstname.lastname@example.org.