Weight vs Speed

Weight vs Speed

Is that 1kg lighter bike worth it?

If you have been cycling for a while, you likely know that there is an inherent pressure on cyclists is to be as light and strong as possible. This not only includes the strength and weight of your body, but it also includes the strength and weight of your bike. After all it’s a simple concept, the more or less you weigh, the more or less energy it will take to pedal your bike. This is how we are conditioned in this world of KOM’s and comparing ourselves to our fellow riders.  It seems we are conditioned to define how good a cyclist we are by how quick we can climb a hill. Now forgive me but there is more to riding a bike than climbing a hill. Let’s look at cycling a route that is the true sense of cycling, sure climbing is a big part of it, but so is descending or pushing out a flat sustained effort into a headwind, take into consideration the terrain you ride in and what you are training for; a flat TT for example, a hill climb event, a rolling route. 

Of course, it is in your best interest to increase you power to weight ratio, the higher the power to weight ratio the faster you will go… while this statement is true and makes total sense there is also an element of consideration to be had.  Bear with me, and here is an example, we have 2 riders with the same power to weight ration let’s say they both have 3.5w/kg made up of Rider 1 with an FTP of 300w and a weight of 85kg. Rider 2 has an FTP of 225w and a weight of 64kg. It doesn’t take a rocket scientist to appreciate rider 2 will generally climb a hill a lot quicker, however if the terrain changes and the riders drop onto a flat road or a slight descent then Power in this scenario is king. Rider 1 has more power (a higher FTP) and therefore will be quicker on the flats and descents as the rider can sustain a higher power output. What I’m trying to illustrate here is before you start thinking about the only way to increase your speed on a bike is to lose weight you really need to consider the type of riding you are doing.

Another key point is to think about weight as a cumulative thing you and your bike and your equipment. An example here is a bike that weights 9kg and is1kg heavier than say an 8kg will feel quite a difference in weight when comparing the bikes weight (approx. 13% heavier), however if you compare this including a rider weight of say 85kg, the total weight including the bike of 94kg from 93kg, the weight increase is 1.1% which is minimal. So, when buying a bike, a point to consider is should I spend an extra 1k on a lighter frame or spend 1k on better group set or wheels given the weight difference of 1kg is circa 1% of the total rider and bike weight. For me I would look to consider getting better wheels.

Rather than simply looking at weight loss please take a focus to your strength, the greater your strength compared to your weight (W/kg), generally the faster you are going to be on the bike. Two important aspects of this equation are the loss of body fat while maintaining or increasing lean muscle mass and strength. There is a definite tipping point in weight loss and loss of lean muscle mass. This can be generated when drastic weight loss happens to quickly. If you goal is to lose a few pounds in body fat this can lead to a big difference in your power to weight ratio especially when combined with strength and conditioning work and a balance healthy diet. 

So, to summaries there is a lot to gain as a cyclist by reducing your weight including be able to climb faster and even more to gain by simultaneously getting stronger with off bike and smart focused training sessions. Just remember to consider what your goal is.  For example, if you are a flat TT rider or endurance rider where the key is sustained power over undulating roads then the goal would likely to be power driven and sustain a high-power output and not weight driven. If you’re a hill climber, then hitting that ideal weight vs. strength composition is key.