Wigginspirational Science!

By Becky Holmes

 

This week I have been addicted to two things, the Olympics and preparing for my next triathlon.

This got me thinking tonight as I watched Bradley cycle over the finish to claim Team GB’s second gold and I glimpsed Bradley’s amazing bike; how does that work? Surely science must play a huge part in the design of his bike and I wondered if there was anything I could use to speed up my rusty old bike.

Let’s start by looking at his bike.


The back wheel has no spokes.

The spokes on a normal bike cause turbulence as they go through the air and result in air resistance slowing the rider down. The solid design of Bradley’s bike wheels mean there is less turbulence and in turn less air resistance. They are also make of carbon fibre making them extremely light, requiring less energy to make them move.

Where you put the spokes and the mass on the bike wheels also affects its inertia. Objects that have a low inertia, have the mass close to the centre and are easy to spin. Normal bikes are the opposite with all the mass near the rim of the wheel and these have a high inertia. They are hard to spin.

By having a solid wheel and spreading the mass around you lower the inertia and make it easier to spin the wheel. Less effort for Bradley, fantastic! The phenomena is similar to an ice skater spinning. She lowers her inertia by bringing her arms close to her body allowing her to go much faster.

One of these solid carbon fibre wheels will set you back about £1000… and remember you will need one for the front as well!

 

 

Central rest bar on the handle bars.

These are called aero-bars, they allow the rider to rest their body on the centre of the handlebars. Teamed with the high seat and low handlebars they force the rider into a certain position. In this position their body will be very streamlined reducing the air resistance.

You can buy these aero-bars and attach them to any bike. A set of carbon aero-bars will set you back about £450.

 

 

Bradley’s shaved legs.

One theory is that it makes the rider more aerodynamic. At last, one I can copy on a limited budget! Another theory is that if you injure yourself and have shaved legs it will be easier to care for the wounds. Hairy legs will get in the cut as it heals, harbour germs and dirt, and generally just get in the way of healing.

Many dispute the above facts and attribute cyclists shaving to habit and tradition.

Cost of a standard razor? Around £1.19 for a pack of four.

 

 

Personally after considering the science, and comparing the associated costs, I am a firm believer that shaving is worth a try first, and am prepared to try anything to go that little bit faster!

 

Why not check out our ‘Science of Sport‘ shows to learn more about inertia, and our ‘Bloodhound‘ Super Sonic Car show to learn more about air resistance and carbon f

Posted in Physics