Tuesday, January 12, 2010

Power Meters

We get lots of questions about powertaps these days so we figured a little write up was in order. If you don't know what we are talking about, perhaps checking here for background info is a good idea.

In short, power meters offer cyclists a way to measure there performance consistently. There are many variables when you go out to ride. Tire pressure, tire size, wheels, road surface, temperature, and wind all are determiners in your ride. Power meters tell you exactly the effort you are making.

Currently there is only 1 type of power meter we encourage our customers to look at. It is the Cyclops Powertap. For as low as $600, you have a computer that tells you your cadence, power, torque, kljs, mph, everything! Get a wireless PT hub with ant+ and you can hook it straight into your garmin edge 500 or 705 so you get altitude as well as maps/gps.

If you are a competitive cyclist, thinking about power, but thinking you don't want to make the weight sacrifice, please read on. The Pro+ hub weighs in at 460 grams and the SL+ is 412 grams. A standard hub on any road wheel will weigh around 300 grams. We are talking about a 112-160 gram(1/3 of a lb.) weight penalty at the center of the wheel(the place where rotating weight does not effect the wheel speed as much the outer part of the rim). Now, look at the size of this hub, this thing has to be built huge to keep the computer inside it, so the flanges for the spokes are bigger too, thus making the wheel way stiffer than a standard hub.

You can get these hubs in almost any spoke combo for any wheel. 20 hole to 32 hole. zipp 404 to a mavic open pro.

I personally prefer a 24h kinlin 30mm aluminum rim. They are 460 grams and cost $55, so no worries if I crash. Other rims such as the open pro or dt swiss 1.1 make great clincher training wheels, but can also be raced as well.

I honestly do not like to use my powertap for racing, in fact, I don't like using any computers for racing, so I have a powertap for training only and do not care if there is a boat anchor on the back of my bike.

Training with power is a whole other story. The first two weeks felt like my legs hit a brick wall. It was extremely hard to get used to holding watt numbers and watching my heart rate go sky high, but eventually I adapted and got way faster. They definitely work and i am a subscriber.

Crank Power meters, means you do not have to worry about switching wheels, the power is measured through the cranks.
SRM, which retail for around $3000, we do not sell these.

Quarq, makes a sram power meter in both bb30 and regular gxp. Retail is $1900 but do not come with a computer, anything ant+ would work with it. We can order these in for you. The weight penalty is more with the quarq than with the pt hub. I recall 874 grams for a bb30 crank and 650 for a standard bb30 crank...so more than 200 grams.

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