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-   Clydesdales/Athenas (200+ lb / 91+ kg) (http://www.bikeforums.net/clydesdales-athenas-200-lb-91-kg/)
-   -   Powercal for Clyde? No. (http://www.bikeforums.net/clydesdales-athenas-200-lb-91-kg/900399-powercal-clyde-no.html)

mtalinm 07-09-13 10:42 AM

Powercal for Clyde? No.
 
I bought a Powercal HR-based power meter a few months ago. I think it is crap for someone like me who is in the high 200s. The reviews say it calibrates well with a regular PowerTap meter, but I think that is for someone in the 150-200# range. There's no way I'm only putting out 200w when hauling my fat up a 10% grade.

now I don't have the equipment to do the comparison myself, but if anyone else has tried I would be curious. I have changed my weight on the Garmin head unit, and the power generated is still similar, so I assume it is insensitive to that.

I'm thinking of trying the Stages STageOne crank-based power meter. $700 vs. probably more for a new wheel built with a PowerTap, plus, my current wheel is great (no spoke problems yet) and for me a custom wheel would probably be $1000+. so I am thinking of going that way.

wombat94 07-09-13 10:57 AM

A good question... and I'd love to hear if anyone has tried it as well.

I'm currently about 240 and am just starting to look into the PowerCal. I'm not a serious enough cyclist to justify spending $700 - $1000 on a power meter, so I've been intrigued by the PowerCal.

Based on reviews that I've read, I don't think I would get too hung up on the actual wattage measurement from the PowerCal... I'm mostly interested in using it to track relative performance for myself over time... which it seems to do well from what I've read, but I'd love to hear if there are any Clydes with both a PowerCal and a hub- or crank-based power meter and how they compare with one another.

CommuteCommando 07-09-13 11:10 AM

A fairly simple approximation can be calculated if you know how much you have climbed, and in how much time. I use a Strava segment to get this information. P=w/t, where w (work) is total weight(you and bike) times elevation gained. In English units this will give an answer in ft*lb/sec. One horsepower is 550 ft*lb/sec. one hp = 746 W. This is just an approximation, and does not take into account rolling resistance, inertia you may be carrying into the bottom of the hill, or air resistance (which for a Clyde going up 10% ain't gonna be that much). I have found that the non-power meter power calculated by Strava is on the low side, by almost 1/2.

A real power meter is just not in the budget right now, but would obviously be better.

teufelhunden222 07-09-13 12:20 PM

see power can be trick when climbing for a clyde. You have to remember that rpm is a factor in the equation, as well as the torque required. lower gearing =less torque required. usually when I am gearing down, it is becuase my legs are thrashed on the hill and I know I am not putting out huge power. untill you get super strong and have a good balance with cadence you will not be putting out huge power. Its all about precieved effort vs acctual effort. In the end power is just a number. Don't focus on the actual number, focus on the % gain. I mean today if you do 200 watts and in a week you do 210 watts that is a 5% gain which is pretty huge. Its only a tool, not a difinitive factor in how strong you are.

mtalinm 07-09-13 12:51 PM

well this is very intelligent. if I climbed quickly then I could probably argue that I am putting out massive watts. but I do not climb quickly.

ok maybe this thread is all wrong sorry

Quote:

Originally Posted by teufelhunden222 (Post 15831259)
see power can be trick when climbing for a clyde. You have to remember that rpm is a factor in the equation, as well as the torque required. lower gearing =less torque required. usually when I am gearing down, it is becuase my legs are thrashed on the hill and I know I am not putting out huge power. untill you get super strong and have a good balance with cadence you will not be putting out huge power. Its all about precieved effort vs acctual effort. In the end power is just a number. Don't focus on the actual number, focus on the % gain. I mean today if you do 200 watts and in a week you do 210 watts that is a 5% gain which is pretty huge. Its only a tool, not a difinitive factor in how strong you are.


TrojanHorse 07-09-13 03:45 PM

1 Attachment(s)
Obviously you're not me and you may be significantly stronger on the bike than I am but here's my power going up a local mountain road that averages about 6 or 7%

http://bikeforums.net/attachment.php...hmentid=328232

Pretty much low 200s. For me at least the limiting factor seems to be HR on steep hills. I feel like I can put out more power on flats or downhills and that's based on looking at power numbers - I always assumed I'd put more out on a hill until I tried. :lol:

IBOHUNT 07-10-13 06:49 AM

Quote:

Originally Posted by TrojanHorse (Post 15832077)
Obviously you're not me and you may be significantly stronger on the bike than I am but here's my power going up a local mountain road that averages about 6 or 7%

http://bikeforums.net/attachment.php...hmentid=328232

Pretty much low 200s. For me at least the limiting factor seems to be HR on steep hills. I feel like I can put out more power on flats or downhills and that's based on looking at power numbers - I always assumed I'd put more out on a hill until I tried. :lol:


Was that walking up that hill? :lol:

TrojanHorse 07-10-13 09:32 AM

Quote:

Originally Posted by IBOHUNT (Post 15833830)
Was that walking up that hill? :lol:

Dude, I was flying up that hill! (the "for me" is assumed of course).

IBOHUNT 07-10-13 10:08 AM

It's quite possible that you're only putting out ~200W.
When it comes to climbing I go into survival mode not attacking the hill. I don't want to cross train...

Here are some results from Strava while I was using a Powertap hub. These were not all out efforts, but a Tempo HR zone.

Distance 0.6mi
Avg Grade 9.2%
Elev Difference 290ft
Elev Gain 290ft

Elapsed Time 00:06:17
Resting Time 00:00:00
Average Speed 5.7mi/h
VAM 844
Average HR 155bpm
Power 256W Powermeter


Distance 1.8mi
Avg Grade 6.3%
Elev Difference 608ft
Elev Gain 608ft

Elapsed Time 00:12:22
Resting Time 00:00:00
Average Speed 8.9mi/h
VAM 900
Average HR 154bpm
Power 292W Powermeter


And here is a segment that came at 94 miles into a ride. Low VAM, low HR and low power.

[TABLE="class: stats"]
[TR]
[TD]Distance[/TD]
[TD="class: segmentDistance"]6.4mi[/TD]
[/TR]
[TR]
[TD]Avg Grade[/TD]
[TD="class: segmentAvgGrade"]6.4%[/TD]
[/TR]
[TR]
[TD]Elev Difference[/TD]
[TD="class: segmentElevDifference"]2,165ft[/TD]
[/TR]
[TR]
[TD]Elev Gain[/TD]
[TD="class: segmentElevGain"]2,248ft[/TD]
[/TR]
[TR="class: spacer border"]
[TD="colspan: 2"] [/TD]
[/TR]
[TR="class: spacer"]
[/TR]
[TR]
[TD]Elapsed Time[/TD]
[TD="class: elapsedTime"]01:05:06[/TD]
[/TR]
[TR]
[TD]Resting Time[/TD]
[TD="class: restingTime"]00:07:02[/TD]
[/TR]
[TR]
[TD]Average Speed[/TD]
[TD="class: avgSpeed"]5.9mi/h[/TD]
[/TR]
[TR="class: climb-only"]
[TD]VAM[/TD]
[TD="class: vam"]608[/TD]
[/TR]
[TR]
[TD]Average HR[/TD]
[TD="class: heartRate"]143bpm[/TD]
[/TR]
[TR]
[TD]Power[/TD]
[TD] 215W http://d26ifou2tyrp3u.cloudfront.net...717584e995.png[/TD]
[/TR]
[/TABLE]


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