Speed Banking!

 

Hi

My friends Carole and John up the road have been passing their "New Scientist" magazines on to me, and a question that came up in the Back Pages section intrigued me. The question and some of the replies received is shown in the pic - to me the replies don't answer things from a scientific (ie nerdy recumbent cyclist) point of view.

The question is "Cycling on hilly roads, what is the best option to save energy: go as fast as possible downhill to gain momentum for the next climb, or stop pedalling to have a rest and regain some strength?"

Here is my answer!

The question really ends at the word "energy". "Go as fast as possible downhill to save energy for the next climb" can be done in a few ways, and it needs to be considered that there are 2 categories of things that make bikes go faster. These are: reduce things that hold a bike back (Chris Daniel mentions aerodynamic forces as well as rolling resistance, mechanical friction and inertia and gravity forces) and increase things that push a bike forward (pedalling, electric assist).  

On most bikes we can control wind resistance through posture  - being very vertical on a bike increases wind resistance, crouching low over the handlebars decreases wind resistance. However the aerodynamic low crouch which decreases frontal area can be painful for some riders. Unlike pedalling harder, this is a way of going faster that does not use extra energy, however it can come at the cost of comfort so is not always used.

However in cycling, and even in road going cycling, there are cycles which have decreased wind resistance compared to most bicycles. These are called recumbent cycles, and the best ones improve aerodynamics in both of the possible ways, that is by decreasing frontal area, and improving the aerodynamic shape (reducing the drag coefficient) without significantly increasing weight or causing physical discomfort. The result of inherently improved aerodynamics is to make downhill descents faster and to gain momentum for the next climb without extra exertion or discomfort.

 

So why don't we see more recumbents on the road? That is a question as old as the recumbent bicycle itself (1930's) and the sets of answers to that question are almost as old. Answers - and disputable answers  - also date from the 1930's, and The Player's cigarette card series (1939) pictures renowned cyclist Evelyn Hamilton on a recumbent but has the following to say against recumbents: riders tire more quickly due to greater exertion due to use of back muscles, and due to the low position, riders gather more dust.

The quick answer (to why don't we see more recumbents on the road) might be that although they commonly reduce effort and physical exertion and anguish, they induce mental anguish in many people! Recumbents are a minority set of vehicles amongst the minority transport option of cycling, and it is almost unimaginable that a Tour De France devotee would mention to his or her bicycle racing mates that recumbents are faster.

 As a recumbent cyclist I advocate for recumbent cycling and think of the great Mark Seymour / Vika and Linda song, When will you come to your senses? (When will you come to your senses, when will you fall for me?) in regard to recumbent cycling, that is, it would be great if you could change peoples' minds but unfortunately you can't!