If someone gave one to me I'd use it. It reminds me of one of BikeSnobNYC's posts where he devised his own $25 power meter. Everytime you looked at it it read out: YOU SUCK

I'm afraid that's all the useful information my power meter would give me.

This page gives a very good explanation.

Under identically the same conditions your power would be almost identical since all your power is being used to fight friction, wind resistance and any changes in elevation.

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George, I love your enthusiasm for cycling and your willingness to learn and try new things. Understanding power and training with power can really up your game. How your use the power and endurance is up to you. Choosing to train with power is like deciding if you should take the blue pill and return to the matrix or take the red pill and see how deep the rabbit hole really goes.

The simulator in the link works pretty well for climbing and no wind. I found that entering wind velocity results in totally bogus answers. In general, most of the simulators are pretty accurate and indicative of the sustained power it takes to do a climb. The reason is the speeds are lower and aero effects are minimized. For climbs, the power calculation is about lifting a known mass up a hill at a constant speed. That is physics 101. It is highly unlikely (99.99%) that you did 414 watts for a sustained effort. A typical sustainable power for a recreational cyclist is 120 to 160 watts. So if you weigh 170 pounds, climb a 6% grade at the rate of 6mph for an hour, you will need about 160 watts continuously for that hour. 160 watts will move a rider on the flat with no wind with hands on the hoods about 17 mph. In general, it takes me about 185 watts to travel 20mph on the flat with hands on the hoods and no wind with a good road surface.

200 watts of sustainable power is very good and 300 watts of sustainable power is a monster. One can see that 400+ watts of sustainable power is achieved by a few of the top riders in the world. The key is sustainable. And that standard is sustainable for an hour. Sustaining anything for an hour is not easy. So if you could climb a 6 mile, 6% grade hill at 6 mph weighing 170 pounds, your functional threshold power FTP would be 160 watts.

If 160 watts is your FTP, that amount of power is hard to make after a few minutes. Talking becomes difficult but possible and breathing is deep but not gasping. You should feel that you could keep this up for another 50 minutes but it was going to be painful That is what FTP feels like.

Once you know what your FTP (zone 4 or z4) is, all power training is based on that value. z5 or VO2 max intervals are done at a power great than 106% of FTP for 2 to 5 minutes. Zone 1 or recovery is 45% of FTP. Heart rate becomes irrelevant and many that train with power do not record HR.

A rider with a 160 watt FTP can surge for a few seconds to 450 watts or so. However, the larger the surge and the greater the duration the more impact it has on the body which you pay for in the future with fatigue and a lessoned ability to surge again.

So what a power meter and power training does is quantify the workout and allow post ride review of the effort. Hence, one can train harder and recover better. The punch line is if you want to train harder and/ or more effective, a power meter will assist you in achieving that goal.

Everyone reading this has a power meter available. It is called a stretch of flattish road, a hill and a timing piece. Climb the hill and record your time. Climb it again and again and each time record your time. If the time is the same on each climb the average power will be about the same for each climb. If you climb it faster, your average power increases. The same is true for a flat stretch of road. The power meter is a way to capture all the information, display your power at any moment in time and take into account wind, road surface and body position. Before power meters, all we had was distance, slope and time.

NOW What, I'm a failure, what can I do, what can I do. Anyhow now that I'm done with that, I wonder if I get that Garmin 500 edge, can I download any software to give me a more accurate reading for Watts or power used. I know a lot of guys on the road forum use the same link that I've been using, but that's not saying much either. I can't get a power meter right now and I really don't think I need it, for the kind of riding I do. I was basically using that web site to find out how many calories I used for the ride. If the watts are off that would mean the Calorie readout would be wrong as well. I guess all I can do is check how far I've gone and the average speed. The thing that comes to mind now is, what did riders do before the power meter came out?

I think the HRM comes in handy and now that I know my maximum HR is, which is 169, I have a my different Zones figured out. So that does help, but I would still like to get something to figure watts out, beside a meter. Anyhow thanks for setting me straight on that web site. You wouldn't happen to know a better one would you Rich. Thanks for the reply.

George-a cycling buddy of mine was a regional distributor of iBike. You might check it out:

https://www.ibikesports.com/

Oh, that's good.

Thanks Joe, that really looks like what I need. I'll read more about it tomorrow.

Careful with Ibike. Ibike may be a solution for time trialists. I know of at least 2 racers who use it on their TT bike. Ibike relies on a calibration of the coefficient of drag via a coast down test. So for TT riders who are in the same position on generally smooth roads by themselves on the course I think it may be good. For riding in various positions (tops, hoods and drops), in a pack, rough roads and etc, Ibike IMO is not accurate enough to justify the cost. It is still expensive and comparable to a wired power tap.

George, I use that web site also and think it is pretty good. It has its limitations. There is a new power meter that may hit the market in the next quarter this is included in a Speedplay pedal. The target price is about $800 and includes the pedals. You can move the pedals from bike to bike. The company is Metrogear. We will have to see.

Thanks again Rich, I'll just wait until something comes along. I got a feeling power meters will come down, just like everything else. If they want to keep moving them and newer models come out. What comes to mind is the calculator. Remember when they came out.

I saw a picture of that and thought it was not real - it will be great if it really comes out and it mat be the thing that puts me over the top on the justification for a power meter.

I wonder if they ungraded the ibike? It gets some good reviews.
https://www.ibikesports.com/documents...ing_Dec_09.pdf

Had to read this a couple of times...

To play devil's advocate:

HRM make sense to me for recreational riders if they use it to slow their rides down. It's a strong tendency even for duffers to speed up during a nice ride and push too hard when you shouldn't.

But wattage calculations seem pointless to me.

My nemesis is hills, of which there are a bountiful supply in my area. When I'm going up one, feeling the searing pain in my legs, seeing blood trickle out of my ears, and developing tunnel vision with a figure dressed in Gleaming White calling out my name and entreating me to come Home, I can't imagine knowing that that happened at 250W instead of 245W like the last ride being useful information.

I glad to hear you made it home from a ride like that. Now tell me what your getting your readings from.

They are derived from my Ascent program, which is why I have no idea whether they're the least bit accurate.

I dunno, forgive me for saying so, but sitting around and comparing wattage is like having us argue about the sizes of our respective, um, um, aw never mind.......

Power meters are a racers training tool, so that during training a racer can increase his power output, to drive taller gears and therefore go faster. During a race the power meter itself probably adds too much weight and takes too much parasitic power itself to be used. HRM are useful for physical training, especially for those who might going up heart attack ridge, exceed their Max HR and keel over. Useful for overweight and out of shape riders, wanting to fix either.

Crank length? I think mine is pretty average, 170mm. However I have never had anyone comment about my crank length nor has anyone ever complained about the width. I do know that I would never try to ride if my crank was not stiff.

Second base.

https://www.youtube.com/watch?v=vev3NHU_Olk

It sounds like I should just stick with my first idea. Garmin 500 Edge

For a recreational cyclist using a power meter is the equivalent of a runner using a watch to time his runs or a golfer keeping score. Lots of people just want to improve their power/speed/score and a power meter is the easiest way to measure that on a bike.

For context:



Human power output. From D.G. Wilson, Bicycling Science, Third Edition. 2004.

Based on my calculations, I am pretty much a 100w kind of guy.

fify
IMHO, a power meter is about 4 or 5 levels of complexity higher than the comparative tools/sports.

Floyd's epic climb (clean or not) was around 450 or 470 watts, not 750 - still prodigious!

Energy is the amount of work you do to accomplish a specific task. If you bike from Ann Arbor, MI to Chelsea, MI at a certain average speed, you use a certain amount of energy measured in joules, watt-hours (watts times hours), or calories. If you bike from Ann Arbor to Chelsea and back all at the same speed, you use twice the amount of energy.

Power is the rate at which energy is expended. It's equal to force times velocity, and the tricky part is taht on a bike the force is proportional to the square of velocity, being dominated by aero drag, at speed. Power is equal to energy divided by the time over which it is expended. If you expend the same amount of energy in half the time, that's twice the power, and also needed twice the force.

If you bike from Ann Arbor round trip to Chelsea one week in two hours, you consume a certain amount of energy at a certain rate, aka power. If you bike the same route in one hour the next week, had half the time and hence twice the speed. Twice the speed means you applied four times the force. The power in the faster ride was 8 times the power in the slower ride.

It's really hard to go a lot faster than you do.

Based on what I've read, the iBike is still not a broadly useful power meter.