It’s very difficult to actually estimate or even measure how many additional watts correct or perfect pedalling technique would give you, mainly because a pedal rotation is not a fixed constant; you will inevitably pedal with slightly different amounts of power every spin. But what experts tend to agree on is that if you pedal with the same power but with a more efficient technique it will save you energy.
As both a British Cycling & Wattbike coach I have been taught two ways that a rider should be pedalling. Both ways have their merits. The British Cycling technique relies on a coach viewing the riders’ form on their bike and then giving feedback based on what the coach can see. So you can already see a slight problem with it; it relies on the coach being well trained, and having good sight and understanding of correct pedalling technique.
The Wattbike way is more scientific. You can view the force curve of the pedal rotation and actually see lost efficiency on a monitor displayed in front of you. Once you know how the pedal movement should look you can start to test ways to make it better. It does take some understanding; you need to be aware that a single pedal rotation with only one foot will look almost egg like, you will have more power through the downward and bottom sections of the movement and then less power as the foot then comes back up and over the top. You put the two together and you get, if you’re efficient, a sausage shaped picture. If you’re inefficient you get a peanut shaped or figure of eight, in both these pictures the lost efficiency occurs where the line starts to meet in the middle.
The Wattbike method of improving pedalling efficiency is to drop the ankle at the top of the pedal stroke, i.e. just before you apply force, and then drag through at the bottom of the stroke, i.e. like you are scraping something of the bottom of your shoe. The lost efficiency occurs in the point between after applying force on one leg and starting on the other. When you apply the Wattbike technique this reduces this loss.
The British Cycling method is basically an extension on the one from Wattbike. You would still have the dropping of the ankle at the top of the stroke and the dragging through the bottom but you also add in the pulling up of the pedal, i.e. at the same time as applying force downwards on your left leg you are pulling up with your right. This method requires that you keep your ankle very loose throughout the pedal rotation.
I prefer the Wattbike way. That’s not to say that British Cycling are wrong, and some people would argue that their way is more powerful. But when you have the data in front of you it is very hard to dismiss it. Applying correct technique on the road is a different matter. Without the screen in front of you analysing your technique it’s difficult not to slip back into bad habits. And I’m sure, as most cyclists know, that the first thing to go out the window when tired is pedalling technique. One thing’s for certain; unless you’re a pro, or you own a Wattbike, you could probably do better…