BMJ Christmas 2010: Bicycle Weight and Commuting Time

Dr. Jeremy Groves
Dr. Jeremy Groves

Each year, the British Medical Journal publishes a 2-week Christmas Edition over the holidays:

We publish a special two-week issue of the BMJ over Christmas and New Year. We are pleased to consider all kinds of articles, including reports of original research, for this issue and particularly welcome colour illustrations.

The articles accepted for publication in the special holiday issue are typically tongue-in-cheek, and it’s been described as their “left brain issue”. Here are a few articles from past years:

  • Rugby (the religion of Wales) and its influence on the Catholic church: should Pope Benedict XVI be worried?
  • Frankincense: systematic review
  • Billy Bunter and the obesogenic environment
  • Coca-Cola douches and contraception
  • Head and neck injury risks in heavy metal: head bangers stuck between rock and a hard bass
  • Not becoming a communist doctor
  • Back to the future: emergency departments and ancient Greek warfare
  • Bumf: increasing exponentially
  • The cult of the conference bag
  • How to safeguard your ring in theatre
  • Texting shows recovery after faint

With the above in mind, I was excited to see Dr. Jeremy Groves’ “study” on lightweight bicycles and their affect on commute times in this year’s edition. To approach his paper with the proper levity, consider this comment from the introduction: “I toyed with the idea of blinding it but, in the interest of self preservation and other road users, decided against it.”

Here’s the abstract:

Objective – To determine whether the author’s 20.9 lb (9.5 kg) carbon frame bicycle reduced commuting time compared with his 29.75 lb (13.5 kg) steel frame bicycle.

Design – Randomised trial.

Setting – Sheffield and Chesterfield, United Kingdom, between mid-January 2010 and mid-July 2010.

Participants – One consultant in anaesthesia and intensive care.

Main outcome measure – Total time to complete the 27 mile (43.5 kilometre) journey from Sheffield to Chesterfield Royal Hospital and back.

Results – The total distance travelled on the steel frame bicycle during the study period was 809 miles (1302 km) and on the carbon frame bicycle was 711 miles (1144 km). The difference in the mean journey time between the steel and carbon bicycles was 00:00:32 (hr:min:sec; 95% CI —00:03:34 to 00:02:30; P=0.72).

Conclusions – A lighter bicycle did not lead to a detectable difference in commuting time. Cyclists may find it more cost effective to reduce their own weight rather than to purchase a lighter bicycle.

This entertaining paper was clearly all for fun, though there’s certainly much more than a modicum of truth in the conclusion.

Read the full study at the BMJ

11 Responses to “BMJ Christmas 2010: Bicycle Weight and Commuting Time”

  • charles says:

    These findings are very similar to my own experiences. I’ve done similar tests with several different bicycle styles over the last few years and have come to the conclusion that the long wheelbase, drop bar, steel touring style bike with wider, lower pressure tires is the most comfortable (overall) style of bicycle including recumbents unless you are on very smooth roads or your recumbent has suspension. The touring bike is definitely the most practical style bike when is comes to varied terrain, load carrying, maintenance cost and use in traffic. Commute speed seems to be more affected by conditions and rider energy output than any other factor. Certainly bike weight can make a difference when climbing but as the article implied, the harsh ride gives your body a beating making your performance suffer so……….its a no brainer to me.

  • Ryan says:

    LOL that was too funny, I will remember that the next time I get my doors blown off by a fellow commuter on a carbon fiber ultralite ;-)

  • MohjhoRyder says:

    I would think that a good solid randoneer bike would make an excellent serious commuter. High volume tires, a rack, low maintenance build with a comfortable and relaxed riding position would get you to work safely with less stress and strain on your body.

  • David says:

    Surely a better bike would be a 9.5kg steel framed, large tyred, comfortable bike. My steel Surly pacer with 15 year old Dura ace cost less and weighs less than my wife’s Carbon Giant. Good fun overtaking “proper” roadies uphill while riding steel and wearing sandals…

  • D'Arcy says:

    Excellent article. I ride a steel commuter bike and a few of my carbon road bike friends have commented after lifting it, that it’s really heavy. I point out to them that if you took off the panniers that hold my Abus lock, steel locking cable, rain gear, extra mitts and the two books I’m taking to the library the bike is really not that much heavier.

    When you ride an ultra light bike up a steep hill without anything on it you can really feel the performance enhancement. However, add a couple of loaded panniers to it and it fells about the same as my steel frame bike, with of course a more uncomfortable seat.

  • Brian says:

    I’ve decided to lower the weight on my commuter this year. I’m starting with the heaviest equipment on it: the motor. Seriously, at 240 lbs, a few grams off of my frame really aren’t going to make much difference, are they.

  • Lee Trampleasure says:

    I always figure that part of the reason to ride is exercise, so a few extra ounces/pounds on the bike may help me shed a few extra ounces/pounds off the rider :-)

  • Adam says:

    If anyone is interested Grant Peterson also shared his thoughts on the subject.

    http://www.rivbike.com/blogs/knothole_post/310

    Best,
    Adam

  • John Riley says:

    So do you take Grant’s comments as a validation of interval training?

  • Alan says:

    Somehow, John, I think you may have missed the point… ;-)

  • Bicycle Commuting – Part 4 « Find Your Bug says:

    […] And unless your commute its crazy long already, you wont really notice too much of a difference on time. You may lose a few minutes, but if you practice riding more slowly, you can ride without breaking […]

 
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