# Tagged Questions

Power meters and all related data analysis. Power meters measure direct force applied to one of the pedals, crankarm, crankset, rear hub, or other methods. They use cadence in conjunction with the force to measure the power or wattage.

3answers
2k views

### How can one estimate drag for a bicycle?

I am curious how to estimate drag for a bicycle. This has two different framings: Find the amount of power required to ride at a certain speed. That is, when one is traveling at a constant speed, ...
3answers
15k views

### How do bicycle power meters work?

What exactly are they measuring? How do they measure it? What are the implications of the different approaches on accuracy / speed of getting a good measure? It would be helpful if someone could ...
3answers
2k views

### What is a power meter and why do I need one?

So I've been looking to become a triathlete soon and I'm hearing all this talk about power meters. Now, upon googling I found vague information which is why I came here. Exhibit A. That article gives ...
5answers
2k views

### What are the 'easiest' ways to determine functional threshold power?

I recently picked up a powertap and have done a fair bit of riding around and a few races now with it on, so I've started to get familiar with some of the numbers. I would like to figure out what my ...
4answers
17k views

### How do I calculate the power required to climb a hill at a given cadence?

Suppose I ride at a cadence of 50RPM for 10 minutes with a 39x23 gear ratio on a hill with 10% grade. Is there a simple formula to calculate the power output required?