Bicycle Science
From this page you will find links
to:
- Results of Damian's efforts
to calculate the required pedal power for his Marin ('Palisades
Trail') Mountain Bike; Versions are: original OpenOffice.org Calc spreadsheet, saved to Excel, or exported to PDF. The method used was the 'coastdown' technique, as described in the PDF document "Bicycle and rider drag coefficients for all", as linked from Tony Hadland's 'Bicycle Science'
web page. However, in my case I tried to use SI units as much as
possible! The upshot is that (on the flat) I calculate that I would
need to supply
around 100W of pedal power to go at 14mph, and 700W to go at 27mph.
Stop Press - Based on some new types of tests I've been doing I now
think this 14mph pedal power number is too low, perhaps by up to a
factor of 2x, and that the true value is more like 150-200W. The error
is probably due to inaccuracies in measuring the slope of the hill I was coasting down. More details
of the new tests later.........
- Here's an interesting MSc
thesis by Frederik Van De Walle on the subject of 'The Velomobile as a
Vehicle for more Sustainable Transportation' (PDF).
I particularly liked Chapter 3 on the history of bicycle technology,
and Chapter 4 on the velomobile story. It seems that the combination of
the recumbent cycling position and aerodynamically-designed fairings
really can add a lot to the efficiency of human powered machines
(allowing 27mph with a lot less than 700W of pedal power!). But don't
expect such a vehicle to be permitted for the Tour de France any time
soon................(it would be too good)
- A to B magazine are great proponents of a bicycling future (plus walking, scooters, trains, buses etc.). Damian now subscribes.............
- Back issues of Human Power magazine, for more information on the science of cycling.
- For how long can a healthy human
cycle at a given power before becoming exhausted? I guess this is
something best tested by each person individually with a well-calibrated static exercise bike. But
this link
(scroll to the bottom) gives some curves which suggest over 5 hours at
100W, over 2 hours at 150W, and over 1 hour at 200W. But add some
electric assist, and your 'virtual stamina' can increase
significantly..............
Back to Alison and
Damian's home page
This page was last
updated
on
2006-09-22