Information for cyclists who train and race with powermeters




General information and help


FAQ for power-based training


Tom Compton’s is quite possibly the coolest power-related site ever!  Here you can gain a real understanding of interrelationships of power, force, and speed while riding a bicycle.  A similar calculator is available at from 2Peak Training System.


Still have a question?  The Wattage Forum (Google membership required) can provide ready help and advice from that list’s many members, as can the power training section, of, while TrainingPeaks WKO+ software offers a dedicated forum for its users (more about WKO+ below).


More baffled than ever?  Perhaps it’s time to contact a coach from the directory of power-based coaches



Books and comprehensive articles (PDF files require Adobe Acrobat Reader, a free software download)


Empower your training, by Charles Howe, is a brief, introductory article (PDF, 315 KB).


Power: the Ultimate Training Metric (PDF, 1.4 MB) is rider-journalist J. P. Partland’s guide available through the Competitive Cyclist site. 


Training and racing using a powermeter: an introduction (PDF, 452 KB), by Andrew Coggan, Ph.D., was originally written for the USA Cycling coaches’ manual (backup sites: 1 and 2).






Training and Racing with a Powermeter (2nd edition), by Hunter Allen and Andrew Coggan, Ph.D., is a 344 page mass-market paperback book available through Amazon and Velogear.


See Alex Simmons’s review of the first edition here (scroll down to pg. 12), and Stephen Cheung’s review of the second edition here.


The Road Cyclist’s Guide to Training with Power, by Charles Howe

    Part 1  (PDF, 1.15 MB)

    Part 2  (TBA)





They may be commercial in purpose, but the TrainingPeaks WKO+, FasCat Coaching, Velodynamics, and PowerTap sites have numerous useful articles.


Although primarily concerned with component testing, sometimes ventures into the realm of power-based training, with insightful results.


A compilation of power-related personal web sites can be found at the Wattage Forum’s blog page.  The pick of the lot are those by Robert Chung (old site here), Alex Simmons, and Andrew Coggan/Hunter Allen.



Powermeter product information and troubleshooting help

Robert Chung did what is likely the first simultaneous test of several powermeters, and Kraig Willett followed that with a similar test and comprehensive review (backup here) of three systems (Polar, PowerTap, and SRM).  Here are links to product information and help sites:

The SRM (introduced 1986; history here) is a torque-measuring crank that replaces your present model (also see The Bike Age site for troubleshooting help and other usage tips).


The Saris/CycleOps PowerTap (1998) is a torque-measuring hub that builds into a wheel.


In 2001, suffering pangs of guilt for inflicting the heart rate monitor on endurance training, Polar introduced a unique power-measuring system that uses a vibration sensor mounted on the right chainstay to determine chain tension (a force), then multiplies this by chain speed, as determined by a sensor on the rear derailleur.  Presently, they offer three models, the S720i, S-725X, and CS600.  Check out this review of the CS600, and Sandiway Fong’s set-up instructions for the original model, the S710.


The Ergomo (2002) is a torque-measuring bottom bracket available in ISO square-taper or Shimano OctaLink.  Ergomo went into liquidation in 2008; service is still available through, and an Ergomo user’s group can provide help with issues such as installation, calibration, maintenance, etc.


Like the Ergomo, the Bush & Muller PowerReport (2005?) was a bottom bracket that measured torque and angular velocity, but it was never available in the U. S.


MicroSport’s REVOLUTION Power System (announced 2006, due out in 2008) was to have used force-sensing insoles and estimate cadence from the pattern of pulses detected by the insoles, but the project was abandoned before being brought to market.


Brim Brothers has announced plans to market a similar system in late 2009 or 2010.


The iBike Pro, introduced in June 2006, takes a novel approach: instead of measuring total strain at a single point (e.g., the hub, crankset, bottom bracket, chain, or shoes), it attempts to quantify each force separately.  First, values for effective frontal area of rider/bike, as well as for tire rolling resistance, are obtained via a coast-down test, and entered into the system’s handlebar-mounted data processing/display unit, along with rider/bike mass.  Then, using a pressure sensor to obtain air resistance, plus an accelerometer for road gradient and changes in kinetic energy, power output is calculated as the product of road speed and the sum of all forces resisting forward motion.  iBike’s initial problems with accuracy on rough roads, which seemed to interfere with the accelerometer, are said to have been solved with a firmware update, however, some remain skeptical about its performance when rider position changes from the coast-down test.  To learn more, see this discussion group for iBike users (old list here), and check out these reviews at nyvelocity from 2006 and 2009.


The Quarq CinQo (announced August 2007, introduced July 2008) is a spider with 10 strain gages that is compatible with (i.e., bolts on to) several crankarms currently on the market, then transmits data via wireless digital RF using ANT+ protocol to a handlebar-mounted computer.  Presently, Quarq owners must use a compatible computer either by Garmin or iBike, but a unit with many advanced features, called the Qranium, is planned.  Here are reviews by PezCycling News and EnduranceFactor, plus an interview with Quarq founder Jim Meyer.


Note: contrary to occasional claims, Ciclosport models do not actually measure power, rather, they only give a rough estimate based on speed, total mass, and elevation change (as measured by changes in barometric pressure).  This may be accurate enough on steeper grades, but is useless on flat terrain, particularly in group rides or if any wind is present.


Last but certainly not least, TrainingPeaks WKO+ is aftermarket software for analyzing power data, with many advanced tools that make it superior to that provided with SRM, PowerTap, and Polar systems, while Golden Cheetah is a flexible download software that works with several operating systems such as FreeBSD, Linux, Mac OS X, and Windows, and is available under an open source license.