Tuesday, 15 May 2012

Climbing - Part 1 - back to basics

Riding bikes up hills is the thing most cyclists find difficult and it is especially difficult for novices. Most people end up learning to climb without much help or advice and often end up finding it much harder than they ought to.

To understand why riding up hills is hard here's a little bit of science (skip the green bit if you don't like science):

The Science Bit

When Albert Einstein worked out one of the best known pieces of science he probably did it because he realised how important it is for cyclists wanting to ride faster or climb hills.

e = mc(2)

In words the formula reads "energy equals mass x constant squared"

The formula is used to show how much energy is required to move an object. But what does it really mean?

"Energy" most of us understand, although it comes in a variety of forms, and when riding a bike the energy is provided by the engine (the rider) except when heading downhill when something called potential energy comes into play.

"Mass" is a bit like weight in that it is a measure of the amount of material in something (the weight of an object varies depending on its location but mass is always the same - think of how light things are on the moon)

The "Constant" is a way of measuring the things that affect the movement of the object like gravity, friction etc.

When riding a bike on a level surface the constant is mainly made up mainly of air resistance (the coefficient of drag, the CD value car makers used to publish in the 80s, multiplied by the speed of the bike) and the mechanical efficiency of the bike and the drag from the road surface (these last two are relatively minor). The squared bit at the end of the formula means that to double the speed of the bike requires four times the energy.

Riding up a hill the constant includes a measure of the gravitational pull of the earth (itself a constant  called g) as well as the factors applying on the flat. As speed is much lower going up hills the air resistance becomes less significant and the energy requirement to ride against the gravitational pull of the earth becomes the most significant factor.

What does it mean in simple non scientific terms?

So does that mean that the lighter you are the better you can climb? Not necessarily classic climbers like Lucien Van Impe, Robert Millar or Marco Pantani were all very slightly built but what about Eddy Merckx, Bernard Hinault and Big Mig Indurain who all climbed brilliantly and were much heavier riders (with much more mass). The bigger climbers simply needed more energy to climb at the same speed as the lighter ones and in the examples given they had sufficiently powerful engines to be able to produce that amount of energy.

The important factor to be able to climb really fast is to have lots of power compared to how much you weigh (a high power to weight ratio).

There are two main reasons why climbing is harder than it should be for many riders and these are:

a) power to weight ratio is too low
b) technique needs improving

In the following two posts Climbing - Part 2 and Part 3 - I'll take a look at how to use training to tackle the power to weight issue and how to improve technique to climb more effectively.

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