Do you mean what role did tire inflation have to play in the apparent discrepancy?

Based on Robert's plot above, unless you jumped off the rollers immediately at the end of your effort and inflated the tires prior to warming down at ~20 km/hr...then I'd have to say "nothing."

BTW, you know you could fairly easily directly answer the tire inflation vs. roller power yourself in a quick session, right?

edit: BTW, based on your own regression estimates above in post #251, according to your average speed on 11-11-08, you most likely actually averaged closer to 325W for that hour, which is better in line with your data on either side of that session.

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http://bikeblather.blogspot.com/

Yeah, at this point, it's probably easiest for me to do a bunch of 10-minute tests to find the relationship between tire pressure and the power:speed ratio. It may be a while, but I'll post my data and findings. (I ride the rollers less now since I can ride outdoors more, and don't want to irritate the neighbors with the noise.)

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Here is what I find unexplainable about this data.

time/speed/watts/cadence/hrate/distance/torque

Note that then the cadence is zero, that the speed immediately drops to zero and the distance stops ticking over even though the wheel speed could not have suddenly gone from 17.3 to zero then just as suddenly back to 14.4. Obviously, a discrepancy when coasting down here. Suggests to me something is not right with this PM but what could it have to do with whether the power, when pedaling, is proper or not?

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Frank,
An original Ironman and the Inventor of PowerCranks

What evidence would you have that 390-405 W is your functional threshold? I've been doing this for 8 or so years now and have collected a huge sum of data over the years on myself and others and can weed out those anomalous incidents as well as one-off performances. But you can't count on those one-off performances. You have to depend on performance that is repeatable. What data do you have which suggests that 390-405 for close to an hour is repeatable? This isn't a knock against you as you are still learning the ins and outs of power. Have you read up on the "7 deadly sins" for estimating functional threshold? Check http://alex-cycle.blogspot.com/...ven-deadly-sins.html

Is the data at http://freepdfhosting.com/d4dffffb72.pdf yours? If so, I would say your functional threshold is in the 350-360 W range. Still very good, and you probably still have room for improvement over the next few years. If that data is yours and you saw it, what would you deduce from it? If 400+ were truly your functional threshold, does it make sense that your typical power is 10% or more lower? You should be able to hit that power routinely, not once in a blue moon. As an example, see the graph below -

This is one hour normalized power (don't have a plot of average handy). I consider that one point on the right side of the plot an outlier. I don't consider it an indicator of my true functional threshold. Rather, 270-275 W would appear to be the right value, and it's backed up by repeatable data. Looking at the 40 minute data from the above link, the same process would indicate a lower power for you.

Or take a look at this plot

which shows my top 20 rides averaged together to form the basis of what I would consider my repeatable power.

Look at data as many ways possible. Do things like the above, look at shorter duration power and do a critical power analysis, look at the distribution of power from races and look for those dropoffs from one bin to another. Don't rely solely on a single method or data point.

It would appear that in your race files, the meter is set to not include zeroes. Is this correct?

I was looking at normalized power from a couple races and hard efforts last Spring to conclude that FTP range. It may well be optimistic (i.e. that could easily represent something 5% over my actial FTP), and at this point, out of date compared to my current condition. I'll look at my 2009 data again in light of this and come to a new conclusion.

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Can you clarify on "race files"? I generally use a yellow PowerTap head with a PowerTap for indoor workouts, and an Edge 705 with the CinQo or PowerTap for outdoor workouts. In either case, I don't know with certainty which setting I used on a given day. I think I changed my "record zeros" setting at some point. Sorry.

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It is not possible to know for certain. All we can say is you incorporated them into your training and you did X. Now, I think that most who use them tend to see bigger improvements than they otherwise would see but with n=1 data it is, as you know, impossible to know for sure. Surely, if you have gone from an FTP of 270 watts to one of 350-400 watts in one year, that is a greater improvement than is typically seen in that time period. Most at this site would be happy to achieve an FTP of 270, let alone see that improvement, whatever it is.

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Frank,
An original Ironman and the Inventor of PowerCranks

Just out of curiosity, was the 400 watt file in question done with PowerCranks on the bike or regular cranks?

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Frank,
An original Ironman and the Inventor of PowerCranks

I was looking specifically at the files from 4/12, 4/18, and 5/30. The data from all of those dates are really suspect.

Yes, I did the 2008-11-11 ride with PowerCranks, as well as most of the others in that time frame.

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I'm not sure if it's really "worth it" unless it's to satisfy your own personal curiosity...RChung's plot above is compelling evidence that the PT didn't have it's torque zeroed correctly on that day.

But, if that's what it would take to convince you of that...well, have at it :-)

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Which filenames are you looking at? I just want to be clear since this affects which setup I was using.

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200904121423, 20090418-dartmouth-crit, 200905301007

All three of those used the CinQo/705 setup. I believe I had the 705 set to my typical race settings: include zeros, record every second. I zeroed the CinQo at the line for every race. If you're interested in the original .tcx files from the 705, let me know and I'll look into posting them.

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But that doesn't stop you from taking credit for the whole ball of wax now does it?

You REALLY don't get it do you? 270 W is what, 3.3 W/kg for him? I'm sure most on this site would be unhappy with that.

And a 30-50% increase in one year (alas, even a few months) is more than possible with or without your cranks for someone of his initial fitness.

OK, I'm sorry to mention this--but here goes: I think any analysis you're doing r.e. plotting your power is going to have to exclude the data from the Edge/Quarq combo.

Please note, I'm not suggestion the issue is the Quarq--it could be the head unit. However, the data are totally f'ed.

Here's what I mean:

Crazy Artifact:
Duration: 0:53
Work: 9 kJ
TSS: 0.3 (intensity factor 0.477)
Norm Power: n/a
VI: n/a
Pw:HR: -21.14%
Pa:HR: -15%
Distance: 0.333 mi
Elevation Gain: 0 ft
Elevation Loss: 86 ft
Grade: -5.4 % (-94 ft)
Min Max Avg
Power: 179 179 179 watts
Heart Rate: 99 137 117 bpm
Cadence: n/a n/a n/a rpm
Speed: 18.3 32.5 24.1 mph
Pace 1:51 3:16 2:29 min/mi
Altitude: 88 174 130 ft
Crank Torque: 0 0 0 lb-in

Another Crazy Artifact:
Duration: 0:27
Work: 10 kJ
TSS: n/a
Norm Power: n/a
VI: n/a
Pw:HR: -6.22%
Pa:HR: 80.16%
Distance: 201 ft
Elevation Gain: 1 ft
Elevation Loss: 3 ft
Grade: -1.5 % (-3 ft)
Min Max Avg
Power: 354 354 354 watts
Heart Rate: 104 112 108 bpm
Cadence: 3 3 3 rpm
Speed: 0.4 16.7 7.3 mph
Pace 3:36 137:57 8:13 min/mi
Altitude: 46 49 47 ft
Crank Torque: 0 905 181 lb-in

And Yet Again:
Duration: 0:41
Work: 15 kJ
TSS: 1 (intensity factor 0.949)
Norm Power: n/a
VI: n/a
Pw:HR: -11.43%
Pa:HR: -48.92%
Distance: 0.293 mi
Elevation Gain: 0 ft
Elevation Loss: 68 ft
Grade: -4.7 % (-73 ft)
Min Max Avg
Power: 356 356 356 watts
Heart Rate: 124 146 135 bpm
Cadence: 3 5 4 rpm
Speed: 18.3 31.6 25.8 mph
Pace 1:54 3:16 2:19 min/mi
Altitude: 124 193 161 ft
Crank Torque: 0 961 171 lb-in



All of your Quarq/Edge files are rife with these. In looking at raw data of the files, you were coasting at these times. I'm way more familiar with the Power Tap and SRM, so I'm going to defer to Tom for some help on the cause of the error. Regardless, these files look pretty useless for establishing anything. I know this is a bummer, but best to figure it out now.

And in the follow up post:
http://alex-cycle.blogspot.com/...s-testing-ftp-2.html
I think I should add Sin of Sins #11 - that of repeatability (although I mention it in SOS #5).

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Training Plans -- Power Meter Hire -- SRM Sales Australia -- cyclecoach.com -- My Blog -- Sydney Turbo Studio

One thing to consider when evaluating these files, especially when comparing those ridden on the road with regular cranks to those on the PowerCranks is some users find that their power is higher on the PowerCranks than when riding regular cranks. Probably because they revert back to older patterns when on regular cranks, not being sufficiently "indoctrinated" yet. That was the experience of Greg Taylor who was seeing a 30 watt difference. That difference convinced him to race on the PC's. While he DNF'd at Kona, he just set an age group record in Arizona doing a 10:09 as a 55 yo, racing on PowerCranks. This is about 18 minutes off the old record.

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Frank,
An original Ironman and the Inventor of PowerCranks

And, what initial fitness is that? Didn't he ride across the country the year before he got the PC's.

Ugh, all we say is our average user sees x amount of improvement in a certain amount of time. Nowhere will you see that we attribute all of that improvement to the PowerCranks. People seem to assume we say that but nowhere do we ever say that and I have never said that. I don't know how much extra the PowerCranks offer. All I know is what we see overall, on average. What is wrong with that? Further, many who have plateaued see substantial improvement so we suspect all of that is due to the PowerCranks. You just didn't happen to be one of them but, then again, you didn't use them as we recommended.

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Frank,
An original Ironman and the Inventor of PowerCranks

Actually, I suspect most at this site would be more than happy with that. Look at the average bike speed at an IM and calculate what power number that probably represents and look at the average weight of the average participant. If that calculated to be 3.3 w/kg I would be very surprised. Maybe that is a poll Dan could take. Unfortunately, most of the people here don't own power meters so they don't know how good or bad they really are so we would only be getting the numbers from those who have the PM's.

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Frank,
An original Ironman and the Inventor of PowerCranks

'

I don't know which file you pulled this from, but clearly the zero offset wasn't set correctly. That is apparent from the fact that torque doesn't go to zero when cadence does.

This would happen with Garmin 705s that had older firmware versions (typically v2.1, v2.6 and v2.8). The Garmin would interpret other Quarq CinQo messages (battery state, device ID, etc) as power messages while coasting. They have since fixed that with the current firmware v2.9. The rest of the data should be okay if he excludes the faulty recordings from when he was coasting.

Mieke
Quarq Technology

And what does that have to do with anything? If I walk across the country can I run a 3 hour marathon? Heck, if I jog at a 10 min/mile pace across the country can I run a 3 hour marathon? Volume alone doesn't get you fit.

And neither did Marco Pinotti, yet you seem to take credit for a supposed 15 W gain. I know, I know - see an increase you used them correctly. If you didn't, well, it's just cause your an idiot and don't know how to ride the darn things hard or long enough.

What is the "recommended" way of using them? Your users manual doesn't say much, but does say to work on endurance and your aerobic base. Well, given aerobic base includes things like 75-100% of functional threshold, I'd say I used them as recommended. And if you say, "You didn't use them exclusively." That is correct - in the first 4 months or so of using them I did use normal cranks 1 time a week. But your users manual does not say exclusive use is recommended and that gains can be seen in 4-6 weeks (which I never saw in that time frame or longer), though there is this golden nugget:
Doesn't stop you from making claims about Mr. Soltren. You can't have it both ways.

Well, given IM participants don't ride a 112 mile leg at functional threshold, this sounds like a completely pointless exercise in wild ass assumptions using analyticcycling.com, your preferred way of determining power, be it outdoors or on a trainer :)