View Full Version : Re: bicycle cranks/pedals for measuring power output

Martha Jack
04-07-1996, 10:58 AM
Yes, such a device exists. They are dual-piezoelectric force pedals and
are an integral part of the USOC cycling biomechanics program. As stated
in the Spring 1996 issue of Cycling Science in the article by Jeffrey
Broker, "Cycling Biomechanics: The Olympic Program," These pedals were
developed at UCLA in the late 1980s and refined for Olympic cycling use in
1991. Each pedal contains two piezoelectric transducers, which measure
applied forces in the normal, medial-lateral and shear directions.
Additionally, the location of the applied load and any torque developed
between the cycling shoe and the pedal are measured. Attached to the base
of each pedal is a digital encoder for measuring pedal orientation with
respect to the crank. A third encoder measures crank orientation with
respect to the bicycle. Each pedal has an interface plate that acccepts
either a Look/Shimano, Time or toe-clip-style pedal platform.
An SRM (Schoberer Resistance Measurement) bicycle instrumentation system
was acquired in 1993 by the USOC to expand biomechanical and physiological
testing capabilities. The SRM system, designed and fabricated by a
mecaanical engineer in Germany, measures and stores bicycle speed,
cadence, power output and the cyclist's heart rate.
Data are downloaded through a serial cable to a computer. Data processing
and display are performed by custom software provided with the system.

__________________________________________________ ____________________
Martha Jack, Ph.D. :) E-mail: mjack@beta.tricity.wsu.edu
Biomechanical Engineer :) Voice: 509/ 943-0043
___o P.O. Box 776 :) FAX: 509/ 943-4642 ___o
_ \ to measure forces exerted by the rider and/or power output. If such a
> device exists, I would appreciate advice in regards to where such an instrument
> can be purchased. Also, can the data retrieved be stored and somehow
> downloaded to a computer?
> Your help and advice would be greatly appreciated.
> Thank you very much.
> Sincerely,
> Shane
> --
> Shane K. Best phone: (423) 525-3926
> Biomechanical Engineering email: skb@utk.edu (kimber@utkux.utcc.utk.edu)
> University of Tennessee URL: http://funnelweb.utcc.utk.edu/~kimber/
> __O __O __O
> _-\