Author Topic: How much power?  (Read 5406 times)

quixoticgeek

  • Mostly Harmless
How much power?
« on: May 29, 2018, 04:28:17 pm »

Was having a discussion earlier today with another cyclist about how much power various types of cyclists can produce for a sustained period. We tried googling to get some data, but came up inconclusive.

So I'm wondering if any forumites know what watts/kilo they can maintain for a long time, and for 15 minutes? What would be typical values for a novice male and female cyclist? Does anyone know of any publicly available research on the subject?

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: How much power?
« Reply #1 on: May 29, 2018, 04:30:32 pm »
googling "watts kg cycling" and looking at the images will give you a table such as this:-



FT = Functional Threshold which is a fancy name for power than you can deliver for 1 hour

FWIW I've done the bulk of my Audaxing way down in the "untrained" or very low "cat 5" territory.
"Yes please" said Squirrel "biscuits are our favourite things."

quixoticgeek

  • Mostly Harmless
Re: How much power?
« Reply #2 on: May 29, 2018, 04:48:12 pm »
googling "watts kg cycling" and looking at the images will give you a table such as this:-



FT = Functional Threshold which is a fancy name for power than you can deliver for 1 hour

FWIW I've done the bulk of my Audaxing way down in the "untrained" or very low "cat 5" territory.

I found that table too. But couldn't find any info saying how it had been derived...

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

zigzag

  • unfuckwithable
Re: How much power?
« Reply #3 on: May 29, 2018, 04:53:07 pm »
it's easy to know your power curve if you use a power meter. people are different in their muscle composition (fast/slow twitch) as well as the type of riding and training they do. power to weight and endurance matter more than pure power in road cycling. here's an entertaining video comparing a roadie vs a track sprinter.

simonp

  • Omnomnomnipotent.
Re: How much power?
« Reply #4 on: May 29, 2018, 05:14:13 pm »
This year, to date, about 3.9W/kg for 5 minutes, 3.2 for 15 minutes, 3.1 for 20 minutes, and for 1h 2.7W/kg; but I also managed 2.7W/kg for 1h15 this year which suggests my 1h value is an underestimate. I never do 1h all out efforts which means my true 1h power is probably higher than 2.7W/kg.

The data show that probably I need to work on muscular endurance.


Re: How much power?
« Reply #5 on: May 29, 2018, 05:30:51 pm »
Here's the graph of my last ride and my this year power numbers (only have numbers for this year).
[/url]2018-05-29_05-21-47
Weight ~75kg, FTP ~ 248,
Duration, W, W/kg
15 sec, 754, 10
1 min, 443, 5.9
5min, 313, 4.17
20 min, 261, 3.48
1 hr, 248, 3.3

I've not been training properly for very long (8 months or so), but I've ridden quite a lot over the years (am now 41, never raced).

pdm

  • Sheffield hills? Nah... Just potholes.
Re: How much power?
« Reply #6 on: May 29, 2018, 05:47:39 pm »
Having had access to a Wattbike at the gym I have been dragged along to by my SO this year, I decided to do a few test routines to measure things although my motivation on a static bike does leave a bit to be desired so it may under-measure things a little...
My Functional Threshold Power (FTP) is allegedly 270W which gives 2.8 W/kg for 1 hour at a heart rate of around 144.

FWIW, I'm on the wrong side of 60 and mildly fit, cycling about 100 scenic miles a week (plus occasional extra jaunts) year round.

Re: How much power?
« Reply #7 on: May 29, 2018, 06:01:05 pm »
My Functional Threshold Power (FTP) is allegedly 270W which gives 2.8 W/kg for 1 hour at a heart rate of around 144.

An FTP of 270W is very respectable and quite an achievement if you don't do any training other than recreational cycling.

mattc

  • n.b. have grown beard since photo taken
    • Didcot Audaxes
Re: How much power?
« Reply #8 on: May 29, 2018, 07:07:17 pm »
My Functional Threshold Power (FTP) is allegedly 270W which gives 2.8 W/kg for 1 hour at a heart rate of around 144.

An FTP of 270W is very respectable and quite an achievement if you don't do any training other than recreational cycling.
"100 miles a week year round" is plenty to have a training effect!
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

Kim

  • 2nd in the world
Re: How much power?
« Reply #9 on: May 29, 2018, 07:09:18 pm »
I'd love to see the power meter equivalent of that wind-tunnel testing of luggage and mudguards...
To ride the Windcheetah, first, you must embrace the cantilever...

Re: How much power?
« Reply #10 on: May 29, 2018, 07:40:12 pm »
I found that table too. But couldn't find any info saying how it had been derived...

I think it's based on a lot of research and studies. It (or something very like it) is quoted in Allen and Coggan's book _Training and Racing with a Power Meter_.

I've no reason not to trust it.

Here's my critical power plot back from when I was doing Audaxes regularly:-



I was ~80kg back then, so that FTP of 220W is 2.75W/kg.
"Yes please" said Squirrel "biscuits are our favourite things."

quixoticgeek

  • Mostly Harmless
Re: How much power?
« Reply #11 on: May 29, 2018, 08:23:35 pm »
I found that table too. But couldn't find any info saying how it had been derived...

I think it's based on a lot of research and studies. It (or something very like it) is quoted in Allen and Coggan's book _Training and Racing with a Power Meter_.

I've no reason not to trust it.

Here's my critical power plot back from when I was doing Audaxes regularly:-



I was ~80kg back then, so that FTP of 220W is 2.75W/kg.

Cool, I've added that book to my next amazon order. Cheers

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Porkins

  • Formerly Nick H. And a long time ago etc, Eurostar
Re: How much power?
« Reply #12 on: May 29, 2018, 08:50:05 pm »
Here's a calculator http://bikecalculator.com/index.html.  You can estimate how far you ride in, say, one hour, then input your weight, weight of bike, riding position and tyre type and the calculator claims to deduce your wattage. The creator, Curt Austin, claims the calculator
Quote
"is actually an 'engineering model' that knows the relationships between power, speed, and the three major forces: gravity, wind resistance and rolling resistance."
  There's no more detail offered than that!! He also
Quote
"holds a PhD in Metallurgy from Rensselaer Polytechnic Institute and has been granted 17 patents...he first posted some spreadsheets that could calculate a cyclist's speed by entering power and the other factors required. He later prepared calculators, much as you see here now, using a very early version of the Java language. These were available at a funky personal account website address for ten years."
Perhaps he was responsible for the charts posted by Greenbank?

The calculator says that if I do 15 miles in one hour on my laden tourer I'm averaging 99 watts. But it makes no allowance for the drag of the bags. I really REALLY want a power meter.

Samuel D

Re: How much power?
« Reply #13 on: May 29, 2018, 09:03:19 pm »
For the calculators, a better bet is to use them to estimate your power when climbing a hill of known height in a known time. The result is pretty accurate then, unlike on the flat (I think go faster on the flat than they estimate for a given power because I’m more aerodynamic than most cyclists).

here's an entertaining video comparing a roadie vs a track sprinter.

Fun vid! Watching that track guy do the six-second test is pretty out there.

Bicycling Science has a graph showing the limits of human power over time and a discussion around this.

LEE

  • "Shut Up Jens" - Legs.
Re: How much power?
« Reply #14 on: May 29, 2018, 09:07:02 pm »

Was having a discussion earlier today with another cyclist about how much power various types of cyclists can produce for a sustained period. We tried googling to get some data, but came up inconclusive.

So I'm wondering if any forumites know what watts/kilo they can maintain for a long time, and for 15 minutes? What would be typical values for a novice male and female cyclist? Does anyone know of any publicly available research on the subject?

J

The most I got to was when I was training hard in Wattbike class last year.

I was 55 & 80Kg
My 20 minute average* was 309W which extrapolates to 293W for an hour at FTP.
Since 1 hour FTP is commonly used to determine Power:Weight  I was 3.6W/Kg at FTP.

Cycling never felt easier and I was climbing away from all my Audax buddies very easily.

My aim last year was to achieve 4W/Kg but life got in the way and I let it slide.  I'm not willing to put myself through the pain to get to 4W/Kg now. 

It made me realise that the top Pro cyclists aren't even human, because they are pushing >450Watts for an hour in a 55km time trial. 
If you can't relate to that then I urge you to try a Wattbike/Zwift trainer just once and see how long you can hang on to 450Watts at 90-100rpm.

*On a threshold test.
Some people say I'm self-obsessed but that's enough about them.

Porkins

  • Formerly Nick H. And a long time ago etc, Eurostar
Re: How much power?
« Reply #15 on: May 29, 2018, 09:13:36 pm »
For the calculators, a better bet is to use them to estimate your power when climbing a hill of known height in a known time. The result is pretty accurate then, unlike on the flat (I think go faster on the flat than they estimate for a given power because I’m more aerodynamic than most cyclists)

Nail on head. The Cd of riders and bikes varies enormously, but the calculator just uses some sort of secret assumptions for average values.

The only info he gives away about his assumptions are a 5% loss for friction of bike parts and 25% physiological efficiency for conversion of glucose to muscular output.http://bikecalculator.com/what.html

Porkins

  • Formerly Nick H. And a long time ago etc, Eurostar
Re: How much power?
« Reply #16 on: May 29, 2018, 11:33:06 pm »
My only carefully recorded ride was 160 miles in 12 hours, 2 hrs of which were rest stops. I was credit card touring with a bar bag and tail pack. If I assume I was on the hoods all the time, and ignore the drag of the luggage but not its weight, and also assume a flat road and no wind, I get 124 watts for the 10 hours of cycling. And 4200 calories burned.

So many assumptions, such vagueness, why did I bother with that! Must buy a power meter.

quixoticgeek

  • Mostly Harmless
Re: How much power?
« Reply #17 on: May 29, 2018, 11:38:50 pm »
My only carefully recorded ride was 160 miles in 12 hours, 2 hrs of which were rest stops. I was credit card touring with a bar bag and tail pack. If I assume I was on the hoods all the time, and ignore the drag of the luggage but not its weight, and also assume a flat road and no wind, I get 124 watts for the 10 hours of cycling. And 4200 calories burned.

So many assumptions, such vagueness, why did I bother with that! Must buy a power meter.

I think I'm going to bite the bullet and get an IQ2 power meter in the Autumn.

Looking at the table above, and based on the numbers strava seems to think for my power output on recent climbs, it seems that I barely make 1.6W/kg. But then I'm a 96kg lump that doesn't get a chance to train much on hills, but has done 3400km this year. On the plus side, I'm on a concerted effort to lose weight, (aim is to lose at least 16 more kg by the start of next years RatN), and every kg I lose improves my Power to weight. If I don't increase my power, but do decrease my weight, by the time I'm on target weight, I'll have a power to weight ratio of over 2w/kg which is a start at least.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Porkins

  • Formerly Nick H. And a long time ago etc, Eurostar
Re: How much power?
« Reply #18 on: May 29, 2018, 11:52:04 pm »
Are you waiting til autumn to get customer feedback on the IQ2? How much is known about it? The estimated delivery date is November. Hmmm. Maybe you should budget for the Vector 3 if you want to be sure of buying something!

quixoticgeek

  • Mostly Harmless
Re: How much power?
« Reply #19 on: May 30, 2018, 12:26:33 am »
Are you waiting til autumn to get customer feedback on the IQ2? How much is known about it? The estimated delivery date is November. Hmmm. Maybe you should budget for the Vector 3 if you want to be sure of buying something!

I do t have the cash for it now, and I am happy to see it proven first.

Vector 3? As in the Garmin pedals? Nah. I don't ride road clip less. So it won't work for me.  Crank power meters aren't an option as I have yet to find one that works with a sub compact 46/30 chainset. Hence liking the iq2.

I think they will work, I'd back the crowd funder if I had the spare cash now.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: How much power?
« Reply #20 on: May 30, 2018, 12:34:37 am »
the numbers strava seems to think for my power output on recent climbs

Caveat Strava. It's woefully inaccurate. I wouldn't base anything on their figures. I can point at a large number of Strava segments it gets completely wrong for me based on its estimates.

2w/kg

I wasn't far off that when I completed PBP but it took an awful lot of mental strength to keep going.

I'm 96kg at the moment. I can slog my way around a 200 or (probably) a 300 but I really won't enjoy it as I'll be bouncing on the time limits most of the ride.

If I lose 10kg I'll enjoy Audaxing again as I'll suddenly have a whole load more spare time.

If I lose a further 10kg then it's a joy, and I can enter silly rides (stupidly hilly, etc) and/or punish myself by choice of lack of gears/freewheel.

But, be careful what you are comparing. On the flat (i.e. TT-ing) W/kg is a relatively useless measure. TT-ing is all about W/CdA and aerodynamic drag is nigh on impossible to measure yourself. CdA has a strong correlation with weight (since the bigger you are the bigger the surface area you have) but there are some very heavy but fast TT-ers out there as they know how to be aerodynamic.

Grand Tour riders worry about W/kg as most of the time W/CdA does not really matter (TT stages excepted).
Audaxers should generally worry about W/kg but trying to keep aero does help.
TT-ers don't really care about W/kg, it's all about W/CdA.

tl;dr as someone who is 96kg I'd be focusing on losing weight rather than gaining power; the latter will come naturally with the work that is required to sort out the former.

Saying that, I have power meters and the sense of progress/development that comes from slow incremental improvements is a massive motivator for me.
"Yes please" said Squirrel "biscuits are our favourite things."

Karla

  • car(e) free
    • Lost Byway - a Pacific bike ride
Re: How much power?
« Reply #21 on: May 30, 2018, 07:42:23 am »
Strava power is a complete work of fiction: it's calculated assuming zero wind and since air drag makes up a massive amount of your power budget, factoring out wind is completely fatal.

Re: How much power?
« Reply #22 on: May 30, 2018, 09:02:22 am »
Vector 3? As in the Garmin pedals? Nah. I don't ride road clip less. So it won't work for me.  Crank power meters aren't an option as I have yet to find one that works with a sub compact 46/30 chainset. Hence liking the iq2.
I think they will work, I'd back the crowd funder if I had the spare cash now.
Do you need both legs power?  If not, keep an eye out for deals and get a left only crank based one. If you are prepared to stick it on yourself then the WattTeam one is currently ~£220, and the Avio one should be available in the next couple of months for similar (or less) money. Otherwise Stages, Pioneer, 4iii or whoever show up in deals for around £200 every so often.
DC Rainmaker seems reasonably upbeat about the IQ2, but expects it to be ready in spring 2019. If I was wanting to train for events next summer, I wouldn't be waiting on the Iq2.

Don't believe Strava power. If you really want an ftp number as a baseline for training, but can't afford/don't want a power meter, see if there are any gyms about with WattBikes that will let you pay a flat fee to use the gym one time. Then you can repeat the test every few months for very little outlay.

Pedal Castro

  • so talented I can run with scissors - ouch!
    • Two beers or not two beers...
Re: How much power?
« Reply #23 on: May 30, 2018, 09:05:49 am »
I found that table too. But couldn't find any info saying how it had been derived...

I think it's based on a lot of research and studies. It (or something very like it) is quoted in Allen and Coggan's book _Training and Racing with a Power Meter_.


Cool, I've added that book to my next amazon order. Cheers

J

I also have that book but there is very little in it that isn't easy to find on the internet.  I coached using HRM back in the 80s and after coming back into cycling five years ago I started training for racing two years after that I educated myself on using power for training purposes. After getting as much info as I could from the internet I added this much acclaimed book to my extensive cycling library but found, as I said earlier, very little in it to add to what I now knew.

Also, bear in mind that comparing power numbers with otherwise not very reliable because it depends on which PM is being used amongst other things. For example I have two power meters, both PowerTap hubs so they will always read less than a pedal based PM as there will be power loss in the transmission. In fact they'll give different values to each other depending if they're on the dirty training bike or the clean race bike.

The numbers are fun to analyse after a ride but I only bother looking at the numbers while pedaling if I'm training on the turbo. The numbers I generate are only useful to compare with numbers generated under identical conditions, i.e. my training setup on the turbo. When I got a new turbo last November I had to reset my FTP.

Re: How much power?
« Reply #24 on: May 30, 2018, 09:20:37 am »
power on its own means so little, there's torque...low power high torque can be very fast, as can be loads of drugs, low torque, as anyone who's watched the giro will have witnessed, so there's the question of how the power is delivered, generated and the shape ( profile) and size of the generator.

funny that many experienced long term folk with power meters actually go on feel for the their fastest performances, and I certainly noticed that I was faster for not looking at mine, having said that they are a good tool if armed with some knowledge of both Coggan and your own body.
look down from t' hills across a land traversed..having known at least a route through, and written it in body and ascribed the mind to its ways