You don’t have to watch many cyclists to see that there is quite a range of pedalling techniques.
There’s cadence for a start, which is the first thing that most people notice, but then there are the relationships between cadence and speed, cadence and power, cadence and gradient, and cadence and aerodynamics. Furthermore, as speed, power, gradient and aerodynamics are all independent those relationships expand again.
What about foot angle? Some people pedal with their toes down, some with their feet flat and some with their heels down. Some people pedal with very little ankle flex, some with a lot. And those who pedal with a lot have the flex in different places. Again, ankle movement sometimes varies with speed, cadence, power, gradient…
They all ‘work’ because ultimately the bike does the right thing. Because the pedals are fixed to the cranks they go round in absolutely perfect circles. Unlike swimming and running, where poor technique prevents you from moving fast from the instant that you start, the effects of poor cycling technique can take time to become apparent. Maybe minutes, maybe hours, maybe days, months, years…
The bicycle is a truly amazing machine. On our own the best we can do is running (or walking), which we can do for a handful of miles at a speed so slow that it’s almost impossible to ride at. In the same time, and with less effort, the bike allows us to travel tens of miles. It does this by recruiting, and then leveraging, the most powerful muscles, and allowing the others to stay relatively relaxed.
Of course it only does this really well with a good setup and good pedaling technique.
So what is good pedalling technique?
Theoretically, from a mechanical perspective, good pedalling involves maximising tangential force and minimising radial force (here is a piece I wrote in 2002).
From a bio-mechanical perspective it means using just the big muscles – the gluteals, quadriceps and calves – while minimising the amount of work any other muscles are doing.
In reality it has a lot to do with circumstance.
I wrote at the top that you don’t have to watch many cyclists to see a range of techniques. I might have added that those few cyclists could be a breakaway group in the Tour de France. In other words, different techniques can work extremely well.
But while those professional cyclists might have different techniques they have a few pretty obvious things in common: high power, low mass, light bikes, and extremely high levels of fitness and VO2. And they’re normally travelling at high speed, even uphill: If they stop pedalling they hardly slow down, so it doesn’t matter if they stop pushing the pedals for a few milliseconds and coast for a bit during every revolution. Everyone can ride like that under helpful conditions – think slight downhill or tail wind. We don’t go as fast as they do because during the milliseconds that we’re not coasting we don’t apply as much power.
With less momentum, i.e. less speed, or more resistance, we lose speed as soon as we stop pedalling. On really steep hills we lose enough speed to make balancing a problem! Under these circumstances a ‘dead-spot’ in the pedal cycle is a bigger problem. Good technique means something slightly different for those without professional power, fitness and speed.
Perfect pedalling might be something to do with minimising the dead spot, the period of time during the revolution when neither leg is applying any tangential force. One approach is to keep the cadence high, the other is to use the ankles change the direction of force (a third is the Rotor approach – to modify the equipment).
Every coach and cycling textbook advocates a high cadence. But a higher cadence comes with a cost – it’s harder work on the cardiovascular system however good at it you are.
I think that the best cyclists understand how to adjust their technique under different circumstances. They understand the benefits and they understand the costs. That understanding might be intuitive or it might be a learned skill – consciously learned or subconsciously learned. I sometimes think that those who don’t, or can’t, adjust their technique get found out – even at the highest level. Power to weight ratios don’t always explain why some riders seem to be better on hills than others, or why a small change in gradient can make so much more difference to some riders than others.