Question for the Coaches: Power meter use and pedal technique, what say you? (Page 4)

Hmmm. Well, perhaps I misunderstood what you were implying. Would you please re-state it?

Well, I didn't write that particular chapter but Andy wrote up the original QA explanation as an expansion on something I did write. As an aside, I split the quadrants in a different way than he does.

We should all find that disquieting.

This made my day.

And as a follow-up, I just read your blog about the power-cadence relationship and how trying to predict a sweet-spot is futile. In contrast, I'm not implying that you could find a sweet-spot, but instead that you could find dead spots where your power is down because either cadence or torque were to low to reach the power that you are trying to maintain.

I haven't had my pt long enough to collect a good range of data, but I am interested to see what is going on at different cadences during constant effort rides. I have my pt on my 700c roadie, but my tt bike is an older 650c with old components (53/42 and 12-22 8 speed cog). I have a hard time in the hills with the lowest gear on my tt bike trying to maintain the same speeds that I can with my roadie. The data may show that it is worthwhile to change the small cog down to a 39 or change the cassette to give me a lower gear for climbing. However, they may show that I can generate the same power at the low cadence which brings up the question of effort and efficiency which is interesting to me, but off topic.

The bolded part already answers your question - you don't need to analyze PT data to get your answer.  Those are monster gears, and there are few people who have any business riding that gearing.

Doh...didn't consider the 650's - although a 22 is still a bit nutty unless you live in Florida.

This thread is huge already and I only read the first page, so forgive me for coming late.

The idea that "power is only measured once" is right, in that it's only power applied to the BB (or rear hub, or chain, or what have you) that gets put to the road.  Whether that's down force on the pedals, or up force, or forward force...doesn't matter. 

I have a kind of unique perspective on pedal technique.  I think there is an important technique, but don't think it has anything to do with pedaling circles per se.

Obviously good cyclists who ride a lot improve their 'technique' (whatever that means).  They do it by necessity.  In those times on group rides when I've been getting my butt whipped by the strong riders on a climb, an attack, a chase...all those race type things that get thrown in, I give 100% effort, am falling behind, but MUST find a way to go faster...that's when I will happen to find wasted energy in my stroke and with time, make that normal.

Is there a short cut to improved technique for novice riders that can improve their FTP without improving their fitness?  Maybe.  I don't know.  I'm not sure past attempts at doing this via spin scan analysis were feasible for one very simple reason.  We never know how the force of the rider's muscles was being applied to the pedals.  They can be pushing 200 watts (with their right leg) at an angle 45 degrees off from orthogonal and it will read as 100 watts.

Pedal based power meters won't do us any good until they measure the angle of force application and compare it to the angle and direction of the crank arms.  My guess is that this measurement, on novice riders, will show force being applied downward to the rear rising pedal.  And that it will show down force being applied to a downward pedal at bottom dead center long after it should be.

I know from personal experience (and this is certainly anecdotal, but informs my theory) that I can be riding at something like 80% RPE, remind myself to relax the rising leg, remind myself to get off the downstroke about 4:30 in the rotation and my RPE drops to 65% without a change in power output.

Absolutely true.  But I would love to see a display on my head unit while training inside all winter that continually tells me how well I'm doing in that regard.  The software solution to evaluate the direction of force and provide feedback wouldn't be trivial but with a pedal-based system telling me that continuously while I train mindlessly for hours on end it could really create a fast-track to improvement.  Direct bio-feedback. 

I think I'll patent the idea so Garmin has to pay me royalties when they awaken to the possibilities.

Yeah I know that lol. The idea was only brought up in context of the OP question about potential application of power and pedaling technique. In reality though, you're absolutely correct. There is a reason bikes have gears.

Tell me about it... If I hadn't spent so much money on a dang powermeter, I could have bought a whole new set of components and a used 700c frame. My TT bike is pretty ancient, but to me it made more since to invest in a training tool at this point. I'll eventually get a new small ring to keep the tighter spacing in the back.