DaveLeeNC

Just a quick comment. I recently purchased a pair of Garmin Vector pedals that I installed on my often used spinner bike. I wanted feedback regarding 'performance' that you don't get from just the spinner resistance thingey and HRM. 'Real performance feedback' came from rides on my real bike.

I am just AMAZED at the performance data that you can get from a power meter. I suddenly find that rides on my spinner bike tell me WAY more than rides on a real bike. And this is enough to entice me to either install some kind of power device on my Bianchi or get really good at swapping my Garmin Vector pedals between the spinner and Bianchi.

I would never have guessed at how valuable/useful power info is (at least to a 'numbers nerd' like me).

dave

chaadster

Yes, a PM changes the way you think and train, bringing a level of consistency to evaluating your efforts that nothing else can touch.

Ragriz

I'm very interested in getting a PM. Just waiting until my bank account will allow for it. I was initially eyeballing the Vector, but I use Speedplays...
Now I'm eyeballing the Brim Brothers. Just waiting for some actual reviews to come out!

no sweat

I've been playing around with inRide virtual power on my KKRM trainer this Winter. It's useful, and saves my trainer sessions from being a total mystery as well as crushingly dull. I'm resisting the urge to buy a "real" power meter for the road bike now... I don't think I really need it.

RomansFiveEight

All I have to use is "Virtual Power" with TrainerRoad. It probably isn't accurate; but it probably is consistent. The consistency is what's important for me. Knowing how much more (or less) power I'm outputting compared to a previous effort is such a big motivator. I'd love to, down the road, have a power meter on my bike. I really wish I knew, for example, how much power I need to put out on some of the tough hills to maintain a certain speed; so I could focus more on training for longer, sustainable outputs at that power level.

no sweat

Fun factoid: 1 W/kg yields 20 feet per minute climb rate (love those mixed units!).

Cyclist performance/power calculator: An interactive, model-based calculator of cycling power vs. speed

Carbonfiberboy 

That comports well with Strava's power and VAM calculations. So if Strava shows a VAM of 750 for a segment, that's 2 watts/kg. Kinda humbling, that thought. Does that calculation include some assumed bike, water, and gear weights?

no sweat

It's just back of the envelope physics. A kg weighs 9.8 Newtons, a Watt is a Newton-meter per second. So one watt of power acting on a kg of mass can raise it against gravity at 1/9.8 meters per second, which is is 20.0816 feet per minute. It's clever to know since racers and trainers speak in W/kg terms. See the calculator I linked for sharper estimates incorporating real world stuff like weight of the bike, rolling and wind resistance. The defaults there are roughly "riding on the hoods, with touring tires".

indjke

Yes, you shouldn't forget that you're not climbing absolutely vertical
The steeper the slope, the closer actual VAM to 20 feet per minute. But in reality at slopes between 5-10% this number is closer to 15 fpm.

gregf83 

Pros riding at 6W/kg are doing around 1600VAM up fairly steep hills (7.8%).

Carbonfiberboy 

Interesting. Going by Strava estimated watts for our tandem on a long, steep, even climb at about that 6W RPE, we are getting our fraction of that VAM for the same fraction of their watts/kg, starkers. My Strava input weight for our tandem and personal equipment, going down the road, is fairly precise.