Stages Power meter

Stages power meter on the left crank.

If you ride in more than two centuries a year or simply like long distance rides or tough climbs then you will benefit from using a power meter.It helps me manage a ride. I would coast along on the flats sometimes and overdo it on steep hills at other times. With a constant display of what power I am putting out, I can step it up on the flats and tackle hills more intelligently.
The Stages Power Meter is probably the most significant upgrade that I have made in years. While it is the most expensive single component on my bike at $650, it has more than made up that cost. It helps me manage a bike ride. I hesitated to buy a power meter for years, especially since they cost so much.

Major Power Meters
SRM	$1,800 - $3,700
PowerTap	$2,000 - $3,600
Quarq	$1,600
Garmin Vector	$1,500
Garmin Vector S	$899
Stages	$650

Before Stages was introduced two years ago, it seemed like only racers and triathletes had power meters. Now that reliable power meters have fallen below $1,000, I think that more people will buy them and ultimately prices will come down further. Power meters like the Polar’s CS600 with Power or the iBike Newton were below $1,000 but were not very accurate. The Polar CS600 measured chain tension and chain speed. The iBike Newton uses forward acceleration and the opposing air pressure and other factors to calculate power. The ones listed above use strain gauges measuring deflection to calculate power.