Opinion: 10 bike fit myths

Persistent bike fit myths are repeated at all levels of the cycling industry, from shop staff to coaches, to bike fitters themselves. These are damaging to the performance and enjoyment of cyclists everywhere. Phil Burt Innovations calls out the worst offenders…

Bike fitting is often described as an art as well as a science, but good, solid scientific research should inform everything our eye and our instinct sees in a rider. Some myths about bike fitting have been around so long no one can tell you or how or why they started, their strength is increased every time they are repeated, and they continue to prevent riders from achieving their most comfortable position or best possible performance. Phil Burt Innovations is about using a tried, tested and scientific process to identify bike fit issues as quickly and efficiently as possible and to solve them effectively. Unhelpful outdated myths are a hindrance in this process, it’s time to put them behind us.

1: Cyclist’s hip flexors are short because of pulling up on the pedals

On a road bike, as you press down on one pedal the other pedal is pushed up. There is negative torque in the upstroke. The hip flexor muscle group is tiny compared to the glutes and the quads, their work is merely to try and get the limb out of the way as quickly as possible. The bulk of the power is coming from the quads and glutes on the opposing leg. EMG and inverse dynamic studies have proven having active hip flexion to pedal is not necessary for road cycling and only really relevant to the very first revolution in a standing team sprint track start. The only reason cyclist’s hip flexors become tight is due to the relatively closed hip position cycling requires you to sustain. In merely standing up off a bike your hip angle opens up and the hip flexor muscle may extend up to a third in length. It’s easy to see why after a two-hour ride the hip flexor may complain a little when it has to lengthen again.

2: Pedalling Technique can be taught

Attempts to teach people to pedal actually decreases overall pedalling efficiency. Studies have proven that asking someone to pull up to decrease the negative torque seen on the returning pedalling leg are counterproductive, and result in an overall loss in efficiency. It’s not to say there isn’t a better or worse way to pedal – just that merely coaching from the outside with instruction in technique – push harder or pull up, makes no difference. You can, however, manipulate bike fit parameters such as saddle height and set back to help certain key muscle groups, such as your glutes, contribute more to your pedalling and this may be over all more beneficial.

3: Crank length is important for torque and power production

Research has been around for some time – see Jim Martins body of work – to firmly establish that crank length makes no difference to your power output. It merely changes your gearing. You would have to go to a crank as small as 80mm or as large as 320mm to see your crank length adversely affect your power output. This is great news as crank length is an important fit parameter for considerations other than pedalling efficiency (for example, hip closure) and riding smaller cranks can open your hip angle up slightly without changing any other fit coordinate.

4: Cycling is bad for your knees

In some ways you could say cycling is bad for knees, this is certainly amongst the most common of cycling injuries, but in the context of other sports or lifestyle cycling is great for your knees! Cycling is the first thing anyone with knee injury does in rehab because there are less eccentric contractions. Cycling places far less destructive loading on your joints. Consider the knee in cycling versus running, for example. Huge forces have to be controlled every time we land and propel off to run. Cycling is a closed system of relatively much lower and predictable forces in two rather than three planes. If you think cycling is bad for your knees pitch up to your local running club and ask them how their knees are or how many of them are carrying injuries, you might find many of them are already cycling due to persistent knee problems.

5: Numb hands are normal

This is the sort of ‘myth’ you might hear from other riders, not coaches or bike fitters; the idea that having numb hands is part of being a cyclist. Numb hands are not normal. You may occasionally have hand numbness on longer than usual rides but it should be transient and quickly alleviated by stopping cycling. If you have constant hand pain, there is something wrong. Its normally a sign that the bike position that has been adopted has too much weight on the riders upper body through a low handlebar/high seat height set up for example. Believing it to be normal is perpetuating the myth that cycling is uncomfortable and that riders should be willing to ‘suffer’. Bike fitting to address position and equipment choice is the first step in solving this.

6: A numb penis is normal

Again, another one you might hear from riders. A numb Penis is not normal; it may be normal for you but you don’t have to put up with it. Saddles and position knowledge can change that. Gap saddles have been designed to relieve pressure on the pudendal nerve, which runs through the middle of the base of the penis and perineum. Pressure here can lead to numbness and erectile dysfunction. Saddle choice, therefore, is very individual as all our of our bodies are unique. Subtle improvements can put an end to these problems. This point is a persistent myth often used to denigrate or embarrass male cyclists. It is an emotive topic and a persistently numb penis is enough for some riders to give up the sport. So it is really important that we shout about solutions and keep riders happy and comfortable on their bikes.

7: If you are not aero you are wasting your power

This myth is motivated by fashion as much as anything. Aero has been the buzzword of the cycling industry for the last couple of years with a broad range of aero bikes hitting the market. Riders love to slam their stems and a quick perusal of social media will tell you how much stick a rider can get for an excess of spacer stack beneath their stem. When it comes to finding your own personal aero position there is a sweet spot, you have to weigh up your comfort versus your aerodynamics. You will lose more power from being uncomfortable than you are losing from not having an aero position. The one caveat on this is that your body is adaptable, over time with the right work and training it may be possible for you to shift the balance more towards aero as you become more comfortable in that position

8: Cadences above 100rpm are more efficient

Popularised by Lance Armstrong, pedalling on the road at cadences above 100rpm became widely accepted as the most efficient way to pedal. If only it was this simple. It may well have been for Lance, but to suggest this works for everyone is to ignore the many components that make up pedalling efficiency. Cadence is affected by crank length and gear selection, for example. Research shows that scientifically the optimal cadence metabolically (in terms of energy expended for work done) is 60rpm. Yet studies show that most people’s preferred cadence is around 90rpm. This is probably a trade-off between metabolic efficiency and force production, and where the balance of those two lies is different for every individual. Interestingly, as power increases, so does your optimal cadence for holding it. Elite cyclists can hold 100rpm relatively easily, because they are well-trained. When it comes to the most metabolically efficient cadence for you, research has shown that it is your preferred cadence. Forcing a rider to pedal slower, or faster, than feels natural to them is actually detrimental.
Saddle

9: Decreasing saddle height increases glute activation

This is another classic piece of off-the-cuff advice, frequently offered rider to rider. Dropping your saddle height does not increase your glute activation or allow you to produce more power, unless your saddle position is currently set too high. Saddle height cannot be addressed in isolation without looking at saddle setback. Finding the optimal sweet-spot between activating the glutes, quadriceps and hamstrings is the objective when setting saddle height. Simply dropping or raising the saddle isn’t enough.

10: Saddle sores are caused by badly fitting saddles

Saddle choice plays a role in saddle sores, undoubtedly, but it is not the only factor. Saddle sores can be caused by position, how and where you sit on the saddle and where your weight is. They can also be caused by excessive movement in the saddle from poor core control, sensitive or irritable skin, poor personal hygiene, lack of or the wrong choice of chamois cream, badly fitting shorts, an inadequate chamois, or changes to duration and intensity of training. It’s a long list and every factor needs addressing, not just saddles. Spending a lot of money on trying different saddles may never bring a rider close to the solution if that is the only aspect they focus on. Riders need to identify what normal is for them, regular saddle sore sufferers would be wise to add a daily note into their training diary on the condition of their skin and saddle soreness as this can help identify and manage the many factors.

Phil Burt, former head physiotherapist at British Cycling, has launched Phil Burt Innovation – offering his elite level expertise and bike fitting services to riders of all abilities. For more information click here.