Bicycle drag vital statistix

[Kingsley]

A guy posted this the "Phreds" Bicycle touring list today, He doesn't cite
the source, but I thought I'd post it here for chewing on.

<quote>
This was done by a physicist and is several years old. I cut and pasted
it into my cycling file. He studied cat 1 and cat 2 racers in actual race
conditions so they were probably on tubulars which have a little more
rolling resistance than clinchers and from what I remember there were many
hills:

Bicycle Drag losses:

60 % Rider Drag.

12 % Rolling Resistance.

10 % Wheel Drag of both kinds-this is aero drag both kinds spinning and
progression, rolling resistance is above.

8 % Bike drag includes entire bike and all components except for wheels.

8 % Inertia of all kinds including rolling inertia of wheels. The wheel
inertia is actually only about 1% of this overall figure and is almost
negligible.

2 % bearing friction and flex losses. etc.
<end-quote>

cheers,
-kt

--
Kingsley Turner,
http://MadDogsBreakfast.com/ABFAQ - news:aus.bicycle Frequenly Asked Questions

[Darryl C]

In article m.au>,
Kingsley > wrote:

> A guy posted this the "Phreds" Bicycle touring list today, He doesn't cite
> the source, but I thought I'd post it here for chewing on.
>
> <quote>
> This was done by a physicist and is several years old. I cut and pasted
> it into my cycling file. He studied cat 1 and cat 2 racers in actual race
> conditions so they were probably on tubulars which have a little more
> rolling resistance than clinchers and from what I remember there were many
> hills:
>
> Bicycle Drag losses:
>
> 60 % Rider Drag.
>
> 12 % Rolling Resistance.
>
> 10 % Wheel Drag of both kinds-this is aero drag both kinds spinning and
> progression, rolling resistance is above.
>
> 8 % Bike drag includes entire bike and all components except for wheels.
>
> 8 % Inertia of all kinds including rolling inertia of wheels. The wheel
> inertia is actually only about 1% of this overall figure and is almost
> negligible.
>
> 2 % bearing friction and flex losses. etc.
> <end-quote>
>
> cheers,
> -kt

Well, there are a large number of variables to consider for each of
these gross generalisations, and that is not intended to be rude to you.
The average rider on the average bike riding on an average road with
average daytime temperature will produce vastly differing results to
Lance Armstrong on a time trial bike or Tony Lockett on a Huffy.

A website that discusses all sorts of energy issues to do with cycling
is the following, but save it for a day when you have a lot of time to
spend on it:

<http://www.analyticcycling.com/>

There is another interesting article from Johns Hopkins University
regarding transfer of power from leg to rear wheel:

<http://www.jhu.edu/news_info/news/home99/aug99/bike.html>

cheers,
Darryl

[TimC]

On 2007-05-24, Kingsley (aka Bruce)
was almost, but not quite, entirely unlike tea:
> A guy posted this the "Phreds" Bicycle touring list today, He doesn't cite
> the source, but I thought I'd post it here for chewing on.
....
> <quote>
> 8 % Inertia of all kinds including rolling inertia of wheels. The wheel
> inertia is actually only about 1% of this overall figure and is almost
> negligible.
> <end-quote>

Er, um... ok. What does this supposed physicist mean by this?

--
TimC
"No, no, you're not thinking; you're just being logical." -- Niels Bohr

[gplama[_117_]]

You also have to take into account the drag of your uber flowing locks
Timc! :)


--
gplama

[TimC]

On 2007-05-24, gplama (aka Bruce)
was almost, but not quite, entirely unlike tea:
>
> You also have to take into account the drag of your uber flowing locks
> Timc! :)

I think a study found they were worth 10km/h, didn't it?

-- Ti "conveniently ignoring laminar flow" mC.