The number of bike fitting services has exploded in recent years, but is the cyclist now any better served by the shop ‘expert’ with a freshly printed certificate from a day-long training course than he was by the club know-all with his plumb line and a thousand homespun theories? Cycling is infinitely measurable, both in the equipment required and the human inputs and outputs; mechanics and physiology can both be quantified by lengths and angles. The position of the hips and the activation of certain, powerful muscle groups has a direct relationship to the angle of the seat-tube; so too, leg extension and power output, cleat position and knee alignment, and myriad other variables that informed sources will notice at a glance.
Given that two directly related, but fundamentally different components combine in the act of riding a bicycle – physiological and mechanical – might it not be useful to create a bike fit with input from parties experienced in both? Navigate your way through the achingly hip thoroughfares of London’s Shoreditch and press the buzzer at the contrastingly unprepossessing doorway to London’s Le Beau Velo, and you will find just such a service.
David Rudisha, circadian rhythms, and enjoying the bike
Mal Pires and Jo McRae are, respectively, vendor of sophisticated (often bespoke) carbon bicycles, and exercise professional with a decade of experience and first class degree in Physical Education and Sports Science from Loughborough University. They share the banter of close colleagues (McRae’s injuries from a recent cycling accident – thankfully minor – provide Pires with all the ammunition he requires on the day of our visit; McRae, as any who know her will attest, is more than capable of defending herself) but practice their art with impressive seriousness. The atmosphere in the mirrored fitting room of Le Beau’s basement premises is light, but purposeful.
Their bike fitting philosophies are holistic and founded in serious concerns for human health in what might, in the broadest terms, be described as western civilisation in the early 21st century. On the day of our visit, the mesmerising form of the athlete David Rudisha and Kenyan dominance of middle and long distance running provides a jumping off point for an engrossing conversation on diet, exercise, movement, and the human body’s response to environment and infrastructure.
Rudisha’s grace, while exceptional, is not freakish, they believe. He is not a ‘once-in-a-generation’ talent, a phrase beloved of western sports journalists to describe the likes of Lionel Messi or Peter Sagan. He is, by contrast, the product of his environment, though admittedly one in which his talent was spotted early and nurtured. For Pires, Rudisha’s teeth and the shape of his face are as revealing as his split times; McRae describes the runner as “a beautiful man”, noting his appearance in the same dispassionate tone in which you might list his medal success. To both, it is blindingly obvious that Rudisha has arrived on the international stage from a culture in which physical activity and natural, unprocessed foods are the norm.
Few bike fitters, perhaps, will consider circadian rhythms and their clients’ sleep patterns when making recommendations, but their ‘holistic’ approach means exactly that. McRae offers the example of a paramedic client struggling physically with shift work. As well as prescribing a series of stretches, she also discussed circadian rhythms, how irregular rest periods might be improved by sleeping in a darkened room with blackout blinds, and the importance of avoiding stimulants like caffeine, likely only to worsen matters. The same client recently returned for a TT fit and has since taken a pay cut to guarantee a more regular shift pattern. The result? “A stone and a half lighter and enjoying the bike a lot more,” McRae says.
Learning the numbers
The turbo trainer serves a variety of purposes, but its use to the bike fitter is perhaps one of the more obscure. With his subject steady, but in motion, Pires is afforded an extended opportunity to observe the positional challenges that must be overcome. The universal goal, of benefit to any and all riders, is optimal positioning of the pelvis, specifically its angle or ‘tilt’.
“There’s a couple of measures that we’ll take around the hip,” Pires explains. “At the front it’s called the ASI joint, at the rear the PSI: anterior, posterior. We measure the tip between those two points. Understanding that allows us to know that you’re firing the major muscles – your glutes – in the leg. Those are the muscles that we want to target; those are the most durable.”
Positioned at too shallow an angle, and the rider will utilise their quadriceps instead: a muscle group that Pires explains will fatigue more quickly than the glutes. It is not only the position of the hips, however, that concerns him: the movement of the knees and ankles will also inform his recommendations.
Measure, measure, measure. Then measure again. Lengths, height, weight, angles, distances, proportions. Pires sets to work with tape, spirit level, and scale, marking positions on skin and shoes as he goes, and taking notes. This is the raw data with which he will begin his analysis and from which he will ultimately form a recommendation, or in the case of a customer seeking a bespoke frame, provide the lengths and angles for a custom geometry. Pires works quickly, but is unhurried. There is no sense of rush; rather, he approaches the task with relish. He will have formed an early opinion from observations made of position and pedal stroke on the static bike, which the hard numbers may confirm or refute.
“For a successful bike fit, we need to have a good understanding of your limb proportions, so I’m going to start with they key body measurements: height, sternum, inside leg, hip, knee, shoulder, weight, shoe size,” Pires says. His measures are taken to divide the body into a series of constituent parts, the better to understand how the whole is constructed. He measures the height of the sternum, for example, to ascertain how much of his subject’s height is accounted for by length of torso and head. Similarly, he measures the inside leg, dividing it at the knee to deduce the length of the femur. “It’s being able to breakdown the proportions and have a think about what will suit someone,” Pires says. “Before I get them anywhere near the fitting jig, I want to look at the numbers in isolation.”
Pires begins with an inspection of his subject’s footwear. The cycle shoe market is a crowded environment, with variations in a host of constituent parts, from closure mechanism to sole thickness, but his primary concerns are condition and fit, both of which are essential to providing the rider with the necessary foot support. Cycling shoes are not decorative items, he says; they are functional. “If they’re not supporting your feet, instability will move upwards, through the knee and into the spine and cause instability around the hips and the back. There’s a knock-on effect: a chain. If one element of the chain is unstable, it will cause a ripple effect through the other links.” Time and usage may have weakened the upper, so that the movement of the foot is no longer controlled. Relegating a pair of worn shoes to training rides, rather than disposing of them altogether, can be a fundamental miscalculation, given that the vast majority of mileage for all but the professional is accomplished outside of race day.
Cleat position, unsurprisingly, provides another vital component of Pires’ analysis, what is sometimes called the kinetic chain. Positioning the centre of the cleat directly below the ball of the foot, and directly above the centre of the pedal spindle is essential to managing the force of the pedal stroke; what Pires describes as its ‘emphasis’. “We want the ball of the foot, when the pedal is in the horizontal position, to be directly above, or as close to, the pedal spindle as possible, rather than fore or aft,” he explains.
Shoulder width is measured to ensure an appropriate bar width, and the rider is weighed to gain a general impression of movement and flexibility (factors assessed in greater detail by McRae), and in the case of heavy riders seeking bespoke machinery, where a custom frame might be reinforced.
Changing the changeable
The act of cycling, as we have discussed, is the outcome of a relationship between anatomy and mechanics. While Pires’ work is informed by his subject’s physiology, he is also concerned by the mechanical component: designing a geometry to accommodate those physical needs. McRae, however, is a specialist in the physical: what might be described as the ‘bio’ component of the bio-mechanical nature of riding a bicycle. “Mal looks at the body in terms of what can’t change – height, limb length, leg length, upper leg to lower leg etc,” she explains, “but what I look at it is what can change: flexibility, mobility, range of motion. We put those things together to make the rider comfortable and effective on the bike.”
McRae works in the same purposeful manner as Pires. While their tasks are performed separately at this stage (only later will they make a joint observation, as we will discover), their engagement with the subject is surprisingly similar. Both, for example, begin by taking a series of detailed measurements, and McRae’s assertion that she is concerned by factors that can be changed, rather than those that are fixed, is immediately borne out.
She sets to work with specialist tools, goniometer and inclinometer, gathering hard numbers to compare with ‘norms’. The subject plays a greater role in this part of the Le Beau bike fit: bending, stretching, reaching, raising arms and legs from standing and prone positions. Her findings are detailed and, occasionally, counter intuitive.
Measurement of the curves of the upper and lower back are made by asking the subject to bend forwards and backwards, and assessment made of the range of motion, measured in degrees. Similar measures are taken of leg extension. McRae compares the readings against values she considers to be ideal. Your correspondent’s fall a long way short, and are typical, McRae says, of cyclists who are also ‘seated workers’. Stiffness in the lower back, detected from measurement of a shallow range of movement that McRae describes as ‘flatness’, can lead to problems, she says: improving flexibility here might be considered a preventative measure. Flatness of less than 20 degrees can increase the risk of lumbar disc injury in a host of everyday tasks, like bending, lifting, and carrying – injuries serious enough to keep you from the bike for an extended period.
While increasing the ability to bend backwards might seem counter-intuitive to obtaining a more efficient cycling position, McRae identifies limited backwards movement as an indicator of a more general dysfunction and a sign that the rider is becoming progressively more ‘fixed’, placing him at risk from the injuries described above.
The interdependent nature of human motion is often described as a kinetic chain. Tightness in the hamstring, typical of the office worker, whose hamstrings are shortened by long periods sitting in chairs and so with knees bent, can pull on the back of the pelvis. Its effect is to reduce the angle of the hips, and as a consequence, increase roundness in the upper back. While the flat-backed position of the elite cyclist (see Wiggins, B) is typically lauded for its aerodynamic advantages, it also provides what McRae describes as “a more powerful pelvic position”; the same sought by Pires in his positioning of the rider for its ability to “fire the glutes”.
The nervous type
The importance to the cyclist of core strength is increasingly understood, not least by professionals who now consider it fundamental to performance. McRae cautions against the notion that unfocussed work to strengthen the torso will have a transformative effect, however. What might be described as ‘general’ work is not enough. Exercises, she believes, must be tailored to specific measurements. Key to her working method is the introduction of specific exercises at the point of fit. Once we have been measured and our range of movement assessed, McRae demonstrates two key exercises that she believes will address tightness in the hamstrings and a limited movement in the lower back: the McKenzie press up and the hamstring stretch with strap.
The nervous system provides the body with a sophisticated mechanism for injury prevention, what McRae describes as ‘down regulation’ of power. Just as the body will not allow you to take a firm grip on a weight so heavy that it believes injury will result from lifting it, so it will shut down the muscles used for cycling when it senses a risk of damage. McRae offers an extreme example to illustrate the point: tightness in the buttock caused by the piriformis muscle, buried deep inside the glute, impinging on the sciatic nerve.
“Let’s say you got out for three hours and you’ve got this problem on your left side,” she explains. “The longer you go, the imbalance will start to creep in. As you start to get tired, the outer glute will shut down and the tight muscles will start to tighten up more. If that piriformis starts to pinch on the sciatic nerve, that immediately will down regulate the power in that leg – it just won’t let you produce the power. You could end up feeling like you have 80 per cent power on one leg and 20 per cent power on the other, and actually you have – it’s the nervous system down regulating power to prevent injury.”
This is not abstract theory, but an understanding of anatomy with direct application to bike fitting. In devising your correspondent’s position, Pires and McRae set the reach of the pedal stroke outside their ‘norms’ to prevent injury as a result of very tight hamstrings. Measured with the goniometer, McRae noted a range of extension between 135 and 140 degrees, where the norm is from 145 to 155. What the body interprets as a comfortable position is one that reduces risk of injury. Setting up the bike in a way that stretches muscles to the end of their range of movement only creates inefficiency, McRae argues. “Think of the highly repetitious nature of cycling,” she says, miming the pedal stroke with her hand. “If you’re stretching that muscle to its end range every time, that’s risk of injury, risk of injury, risk of injury. The body just won’t allow it.”
This leads to another important concept – and hope for the desk bound cyclist with short hamstrings (me). Regular, targeted stretching can increase the range of movement and with it efficiency and performance on the bike. Your first bike fit might not be your last, and your position may adapt with time. What is obvious even to the untrained observer about the position adopted by the professional cyclist – typically, low and flat – is its efficiency. This is underscored, however, by a concomitant flexibility and range of movement in the rider: what the French describe as souplesse and what we call ‘form’. One does not work without the other. What is good for the professional may cause injury in the amateur. The ‘pro’ position is not always the right position.
Fitting the rider
With both Pires and McRae having taken their separate measures, it’s time to climb aboard the fitting jig and allow them the opportunity for a joint assessment. This is where the ‘fine tuning’ occurs. The jig offers a comprehensive range of adjustment for key areas: saddle and bar height, stem length, and even seat-tube and headtube angle. All can be adjusted in pursuit of a position in which the hips are at an angle to activate the glutes and the back is sufficiently elongated to induce a smooth curve along the upper and lower sections of the spine.
For Pires, the importance of the seat-tube angle cannot be overstated. “The seat angle is the most important measure,” he says. “If I can get the saddle in the right place, then everything else will work. If it isn’t correct, the fitting will never come right.”
Minor adjustments are made to the position configured by the pair from their separate measurements, but my pedal stroke on the jig instantly feels more efficient than on the static bike where we began the session. Pires concurs. “In the starting set up, you did look to be sitting ‘on top’ of the bike with a stretch at the lower leg, resulting in a ‘toey’ pedaling action – the toe pointing downwards. Additionally, the upper torso was relatively upright with an absence of a smooth curve from the spine.”
His assessment is confirmed by the numbers. The new position has lowered my saddle height by nearly 2cm (McRae: “That’s a lot”), and their recommended top-tube length is 170mm longer than my usual steed. Both are a response to the measurements of limb and body proportions which revealed my arms and upper torso as disproportionately long. My unconscious response to a cramped position had been to raise the saddle to avoid feeling ‘crumpled’ – an action that only created a sizable saddle to bar ‘drop’ and the unintended side effect of a ‘toey’ pedal stroke. The new position adds a centimetre to stem length and raises the handlebar, which, in conjunction with the lowered saddle, reduces the ‘drop’ by nearly a centimetre. The net effect, as observed by Pires? “Overall this was a more stable, comfortable and powerful position which kept you within a safe range of movement,” he concludes. “It looked much better!”
In an age where bicycles routinely demand an investment of several thousand pounds, the idea of leaving to chance its interface with the rider seems absurd. The cycle industry has responded with a host of ‘off-the-shelf’ fitting packages, but this proliferation has placed new emphasis on the skill of the fitter. Accurate measurements are essential, of course, but it is by interpreting them as a comfortable and efficient riding position that the fitter’s talent is expressed. An approximation might be found in the work of the tailor, and Le Beau Velo, far removed, physically and professionally, from the pile ‘em high philosophy of the chain store, fits the analogy well.