Yet Another Cycling Forum

General Category => The Knowledge => Further and Faster => Topic started by: quixoticgeek on May 29, 2018, 04:28:17 pm

Title: How much power?
Post by: quixoticgeek 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
Title: Re: How much power?
Post by: Greenbank 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:-

(https://barndoorcycling.files.wordpress.com/2016/01/powerprofiling.jpg)

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.
Title: Re: How much power?
Post by: quixoticgeek 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:-

(https://barndoorcycling.files.wordpress.com/2016/01/powerprofiling.jpg)

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
Title: Re: How much power?
Post by: zigzag 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 (https://www.youtube.com/watch?v=PCLvqN9kwuo) comparing a roadie vs a track sprinter.
Title: Re: How much power?
Post by: simonp 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.

Title: Re: How much power?
Post by: DuncanM 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).
(https://farm1.staticflickr.com/878/27564541137_03ecbae259_c.jpg)[/url]2018-05-29_05-21-47 (https://flic.kr/p/HZMtKg)
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).
Title: Re: How much power?
Post by: pdm 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.
Title: Re: How much power?
Post by: toontra 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.
Title: Re: How much power?
Post by: mattc 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!
Title: Re: How much power?
Post by: Kim 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...
Title: Re: How much power?
Post by: Greenbank 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:-

(http://www.greenbank.org/misc/cp3.png)

I was ~80kg back then, so that FTP of 220W is 2.75W/kg.
Title: Re: How much power?
Post by: quixoticgeek 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:-

(http://www.greenbank.org/misc/cp3.png)

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
Title: Re: How much power?
Post by: Porkins 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.
Title: Re: How much power?
Post by: Samuel D 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 (https://www.youtube.com/watch?v=PCLvqN9kwuo) 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.
Title: Re: How much power?
Post by: LEE 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.
Title: Re: How much power?
Post by: Porkins 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
Title: Re: How much power?
Post by: Porkins 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.
Title: Re: How much power?
Post by: quixoticgeek 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
Title: Re: How much power?
Post by: Porkins 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!
Title: Re: How much power?
Post by: quixoticgeek 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
Title: Re: How much power?
Post by: Greenbank 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.
Title: Re: How much power?
Post by: Karla 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.
Title: Re: How much power?
Post by: DuncanM 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.
Title: Re: How much power?
Post by: Pedal Castro 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.
Title: Re: How much power?
Post by: kulturlandschaft 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.
Title: Re: How much power?
Post by: Karla on May 30, 2018, 09:31:45 am
power on its own means so little, there's torque...low power high torque can be very fast

Nope
Title: Re: How much power?
Post by: Cudzoziemiec on May 30, 2018, 10:10:11 am
That video rofl lmao! Goggles!
Title: Re: How much power?
Post by: zakalwe on May 30, 2018, 10:16:40 am
power on its own means so little, there's torque...low power high torque can be very fast

That's not true.  For maintaining speed, power is the only thing that matters.

https://www.youtube.com/watch?v=u-MH4sf5xkY

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.

I do agree with this, though.  I've been using a crank-based power meter for about 4 years and these days, like you said, my strongest performances are done on feel (both short efforts and audax-length rides).  I try to ignore the power readout while riding, as it just spooks/demoralises me.

It takes some time after getting a power meter to learn how the numbers correspond to the "feel" of a ride.  For example, I now know I can do X watts for Y minutes, and what that effort feels like (both at the start and at the end of the effort), but it took me a good 6 months to learn this.  Until you get to that point, you really have to just observe the power numbers and learn what your body is capable of.

Even then, however, you have to be very careful pacing yourself by power.  Even if you know that you can do X watts for Y minutes on a good day, it's very dangerous to hold yourself to that right from the start.  If it turns out that you're having a bad day, and you ignore the feeling in your legs, you'll blow up early and then you're in real trouble.

On the flip side, though, power meters can be useful for telling you when you're going too hard.  I've lost count of the number of times that I've set off at the start of an audax, with everyone else storming off down the road, while I can see from my power readout that if I push any harder I'll pay for it later in the day.  Invariably I pass them several hours later when they've run out of beans :)  In fact, this happens on pretty much every single audax I've done – you'd think people would know their bodies better!

Personally, I've removed the power readout from my Wahoo ELEMNT, but I do find it useful to have it display my power zones on its LED display (with the zones customised to be more appropriate for long-distance, low-power riding).  This way I get to see roughly what power I'm doing, which is helpful in preventing me from going too hard, without being a distraction.
Title: Re: How much power?
Post by: DuncanM on May 30, 2018, 11:04:44 am
Even then, however, you have to be very careful pacing yourself by power.  Even if you know that you can do X watts for Y minutes on a good day, it's very dangerous to hold yourself to that right from the start.  If it turns out that you're having a bad day, and you ignore the feeling in your legs, you'll blow up early and then you're in real trouble.

On the flip side, though, power meters can be useful for telling you when you're going too hard.  I've lost count of the number of times that I've set off at the start of an audax, with everyone else storming off down the road, while I can see from my power readout that if I push any harder I'll pay for it later in the day.  Invariably I pass them several hours later when they've run out of beans :)  In fact, this happens on pretty much every single audax I've done – you'd think people would know their bodies better!
It depends on what event you are doing. I did too much on "feel" on the last TT I did and reached the end thinking that I could have done another mile or 2 at that speed. My time was down and so were my power numbers - I should have looked at my power meter more! Ultimately, if you blow up on a 10, then you learnt something for next time! ;)

The too hard thing applies to pretty much any sort of ride though. :)
Title: Re: How much power?
Post by: zakalwe on May 30, 2018, 11:21:21 am
Even then, however, you have to be very careful pacing yourself by power.  Even if you know that you can do X watts for Y minutes on a good day, it's very dangerous to hold yourself to that right from the start.  If it turns out that you're having a bad day, and you ignore the feeling in your legs, you'll blow up early and then you're in real trouble.

On the flip side, though, power meters can be useful for telling you when you're going too hard.  I've lost count of the number of times that I've set off at the start of an audax, with everyone else storming off down the road, while I can see from my power readout that if I push any harder I'll pay for it later in the day.  Invariably I pass them several hours later when they've run out of beans :)  In fact, this happens on pretty much every single audax I've done – you'd think people would know their bodies better!
It depends on what event you are doing. I did too much on "feel" on the last TT I did and reached the end thinking that I could have done another mile or 2 at that speed. My time was down and so were my power numbers - I should have looked at my power meter more! Ultimately, if you blow up on a 10, then you learnt something for next time! ;)

The too hard thing applies to pretty much any sort of ride though. :)

True – on a TT you might as well go flat out and hope for the best.  But for audaxes and other long rides that's a very dangerous strategy!
Title: Re: How much power?
Post by: chrisbainbridge on May 30, 2018, 08:52:01 pm
You could look at the Zimanox power meter.  They offer a subscription type service.  I have one on my TT bike and really like it.  Bluetooth and ANT.  Left side only so it would work with any set of chain rings.

I find myself riding to power and HR in slightly different scenarios.  On a long flattish section i will run on HR keeping myHR at top Zone 2.  This means that irrespective of wind, drafting, etc I am doing what i can do solidly for 24+ hours.  Then on hills I will change to power as I know the power levels I can sustain for varying periods and I am willing to "burn matches" on a hill.  (Obviously this does not apply in Wales!)
Title: Re: How much power?
Post by: Porkins on May 30, 2018, 08:53:02 pm
I think they will work
I hope you're right, the IQ2 seems the obvious choice for so many reasons. For me, the Dutch team inspire confidence. I like to think they know exactly what they're doing and don't share the American trait of taking a huge punt, then crashing and burning, 
Title: Re: How much power?
Post by: quixoticgeek on May 30, 2018, 08:56:20 pm
I hope you're right, seems the obvious choice for so many reasons. For me, the Dutch team inspire confidence. I like to think they know exactly what they're doing and don't share the American trait of taking a huge punt, then crashing and burning,

Aye.

Just notice that I cycle past their office on one of my semi regular routes.

At €350, it's a lot easier to take a punt on than some of the more expensive crank based ones. And of course I can use any pedals. I really like the idea. I just hope they pull it off.

J
Title: Re: How much power?
Post by: jiberjaber on May 31, 2018, 02:20:35 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!

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

I've moved from Vector2 double sided to 4Viii single sided on 46/30 chainset.  Using Absolute Black chainrings on Ultegra crank arms and now with SPD pedals rather than being limited to only using Keo style with the Garmin set up.  The balance and other Vector metrics were nice to have but overall for monitoring TSS, IF etc the 4Viiii is perfectly adequate and more flexible.  I would have gone down this route initially if it hadn't have been limited by the rear brake design of my original bike preventing anything crank mounted from being used when I started using power meters.

The IQ2 looks interesting as it does open up the potential to be independent of the crank manufacturer which is a good thing - but if q-factor is important to you, then that 16mm is quite a lot, plus the inherent risks outlined in the DCR preview and potential slipping dates.

I guess it depends on when/how long you want to start with power meter based training... you can do a fair bit of HR alone except perhaps but proper HIIT - so you could use a watt bike to get a rough correlation of HR zones / power zones to work from in the intermediate.
Title: Re: How much power?
Post by: Porkins on May 31, 2018, 02:24:51 pm
I read something by the IQ2 people to say they'd be offering shorter pedal spindles to normalise one's Q factor.
Title: Re: How much power?
Post by: quixoticgeek on May 31, 2018, 09:41:28 pm
I've moved from Vector2 double sided to 4Viii single sided on 46/30 chainset.  Using Absolute Black chainrings on Ultegra crank arms and now with SPD pedals rather than being limited to only using Keo style with the Garmin set up.  The balance and other Vector metrics were nice to have but overall for monitoring TSS, IF etc the 4Viiii is perfectly adequate and more flexible.  I would have gone down this route initially if it hadn't have been limited by the rear brake design of my original bike preventing anything crank mounted from being used when I started using power meters.

I actually contacted absolute black to see if any of the crank based power meters that are dual sided (4iiii, Stages LR (Ultegra). They did tell me that there is expected to be a new version of their rings 46/30 rings that will fit a DA9100-PM. Which is nice, but the reviews of said power meter are... not good.

Quote
The IQ2 looks interesting as it does open up the potential to be independent of the crank manufacturer which is a good thing - but if q-factor is important to you, then that 16mm is quite a lot, plus the inherent risks outlined in the DCR preview and potential slipping dates.

The 16mm addition to the Q factor is an interesting one. I'm currently riding Deore XT crankset on my bike, that has a Q factor of about 170mm. The FSA SL-K Modula crankset has a Q factor of 146mm. Add on 32mm, and you're actually looking at 178mm. So over what I'm used to now, it would be only 8mm difference...

Q factor seems to largely misunderstood by many people, and I'm not sure just how much research has been done on it's impact.

Quote

I guess it depends on when/how long you want to start with power meter based training... you can do a fair bit of HR alone except perhaps but proper HIIT - so you could use a watt bike to get a rough correlation of HR zones / power zones to work from in the intermediate.

Aye, I need to have a think about how to train effectively. For now I'm concentrating on getting comfortable on the bike. This means I'm on my 3rd saddle in a month... Once I'm comfy, and I can ride all day without having to treat the saddle sores, then I can work on everything else, including shifting the 27kg of body weight. Which should improve my power to weight...

I read something by the IQ2 people to say they'd be offering shorter pedal spindles to normalise one's Q factor.

Aye, I've seen that too. But, that is likely to be for a very small number of pedal models, likely the most popular shimano or look pedals. Which is fine, if you ride with road clipless...

J
Title: Re: How much power?
Post by: Porkins on May 31, 2018, 09:51:10 pm
Maybe drop them a line to say what pedals you use. It can't be that hard for them to source spindles if they plan ahead.
Title: Re: How much power?
Post by: simonp on May 31, 2018, 10:00:10 pm
SRM are entering the pedal power meter market in a partenership with Look. It’ll be the most expensive option.
Title: Re: How much power?
Post by: Porkins on June 01, 2018, 05:45:33 pm
I'd love to see the power meter equivalent of that wind-tunnel testing of luggage and mudguards...

Which testing? Do you mean Bicycle Quarterly? I wish I could get hold of their back issues on the subject.
Title: Re: How much power?
Post by: Kim on June 01, 2018, 05:57:07 pm
I'd love to see the power meter equivalent of that wind-tunnel testing of luggage and mudguards...

Which testing? Do you mean Bicycle Quarterly? I wish I could get hold of their back issues on the subject.

I think that was the one.  ETA: https://janheine.wordpress.com/2012/05/02/aerodynamics-of-real-world-bicycles/

I'm thinking fat bloke winching up a hill on a sturdy hybrid.  Typical loaded tourist.  Complete novice cyclists.  Children of assorted ages.  Basically, the sort of cycling that isn't sport so doesn't tend to get SCIENCE applied to it, but it would be interesting to see typical power figures for.


(This inspired by a conversation some years ago by a friend at the more extreme 'type 0' end of the sysadmin build spectrum[1] who'd recently taken to commuting by bike.  I posited that I might be twice as fast as him up a hill, but he's probably doing way more work than I am.)


[1] Unisex spaceadmins come in two main body-shapes, referred to as '0' and '1' respectively, on account of the physical resemblance to the digits.
Title: Re: How much power?
Post by: Porkins on June 01, 2018, 09:53:40 pm
Perhaps I want a meter for similar reasons. E.g. how much difference does it make being on the hoods instead of the bar tops even at 10 mph on a touring bike with relatively high bars? It might be infinitesimal but I still want to know.

I also want to test the claim that putting Techwind panniers on your front wheel can reduce drag by 7%  http://cycledifferent.com/angletech-techwind-panniers/ And I want to see if one can gain by using a tail pack to clean up the airflow at touring speeds. And to measure the gains to both riders when one is on the other's wheel.

When I've got some numbers I can refine my notional design for the Ultimate Touring Bike, which will see the light of day when I win Euromillions.

Eta: have you seen this? http://www.cyclingabout.com/speed-difference-between-panniers-bikepacking-bags-aerodynamic-testing-results/
Title: Re: How much power?
Post by: Samuel D on June 01, 2018, 10:01:00 pm
I also want to test the claim that putting Techwind panniers on your front wheel can reduce drag by 7%  http://cycledifferent.com/angletech-techwind-panniers/

“The rear of the ANGLETECH TECHWIND’S™ are square profile to catch those tailwinds and blow you down the road.”

What prevents the bicycle from accelerating until no tailwind remains in this hypothetical scenario?
Title: Re: How much power?
Post by: toontra on June 01, 2018, 10:08:28 pm
This thread has prompted me to put an order in for a pair of IQ2's.  I've long fancied the idea of powermeters but been put off by the cost and lack of interchangeability.  These answer both those issues and worth a punt IMO.  I'm not in any particular hurry  ;)
Title: Re: How much power?
Post by: Karla on June 01, 2018, 10:12:53 pm
Perhaps I want a meter for similar reasons. E.g. how much difference does it make being on the hoods instead of the bar tops even at 10 mph on a touring bike with relatively high bars? It might be infinitesimal but I still want to know.

I also want to test the claim that putting Techwind panniers on your front wheel can reduce drag by 7%  http://cycledifferent.com/angletech-techwind-panniers/ And I want to see if one can gain by using a tail pack to clean up the airflow at touring speeds. And to measure the gains to both riders when one is on the other's wheel.

When I've got some numbers I can refine my notional design for the Ultimate Touring Bike, which will see the light of day when I win Euromillions.

Eta: have you seen this? http://www.cyclingabout.com/speed-difference-between-panniers-bikepacking-bags-aerodynamic-testing-results/

He's using an awful testing protocol.  If you want to do better, Google "Chung test".  Note that you won't be able to measure infinitesimal differences though, and getting down to a few percent resolution will still take a fair bit of work. 

I did thoroughly intend to Chung test my touring setup for this trip, but it was one of many things that ended up being sacrificed to the deadline gods :(
Title: Re: How much power?
Post by: Porkins on June 01, 2018, 10:59:33 pm
Thanks, that's fantastic info!

Just noticed that IQ2 is offering advance booking of notional Shimano pedals with 10mm shorter spindles, at triple the typical price of a standard pedal. FFS. Please somebody tell me my maths is wrong. An XT PD-M8000 is €105, an Ultegra PD-R8000 is €153. https://www.indiegogo.com/projects/cycling-power-meter-at-a-breakthrough-price-bluetooth-sports#/
Title: Re: How much power?
Post by: jiberjaber on June 02, 2018, 09:49:33 am
Thanks, that's fantastic info!

Just noticed that IQ2 is offering advance booking of notional Shimano pedals with 10mm shorter spindles, at triple the typical price of a standard pedal. FFS. Please somebody tell me my maths is wrong. An XT PD-M8000 is €105, an Ultegra PD-R8000 is €153. https://www.indiegogo.com/projects/cycling-power-meter-at-a-breakthrough-price-bluetooth-sports#/

Your maths are probably missing the cost of the "10mm shorter spindles" given its not what they've gear up for initially so they may be covering the risk of making them within the price.  If its a manual job rather than some sort of automated production line approach, then it could well be 3x the cost.
Title: Re: How much power?
Post by: rdtrdt on June 05, 2018, 11:49:05 am
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.

I agree with this.

I mentioned in another thread that I'm a relatively recent cycling returnee, and I've found the data now available via power measurements and Strava more interesting than I'd expected!

I ride in the Peak District, which has no shortage of cyclists, so there's plenty of steep hills in Strava that thousands upon thousands have ridden including plenty of very talented cyclists. My last FTP test was ~3.2 w/kg, and I'm finding that on the steeper hills this power-to-weight has me doing times that are roughly around the top 20%-ish region.

My current goal is to get to ~3.5 w/kg, which I estimate would be approx where I was a few years back when riding pretty well. I rode a bunch of short hilly audaxes back then and would tend to be in the front group of climbers, only occasionally coming across a fellow audaxer climbing significantly faster, which ties in well with your experience at 3.6 w/kg.

At 4w/kg, I can see how very few audaxers could live with you on hills, considering the audaxing demographic and the long distance focus. I don't think I have the appetite (or maybe ability?) for the gruelling punishment it'd require, but if I somehow did achieve 4w/kg I've promised myself a new bike outfitted with Di2, dual-sided power meter and hydraulic disc brakes, etc, fairly safe in the knowledge I won't be paying out...

One of the fascinating things about the Strava data is the vast gulf it exposes lying between someone like me who's reasonably fit (for my age!) but with no innate talent, and the fast people who post times that are mind blowing. It's not just the handful pro-level names, but a whole swathe of extremely fit and talented cyclists posting times that I can only marvel at. Where did talent + hard work ever get anyone?  ;D

I love like the reality-check this all provides. I've always thought testers were mental - which they clearly are - but maybe I'm beginning to get a glimpse of what's in their heads?
Title: Re: How much power?
Post by: quixoticgeek on June 05, 2018, 01:04:38 pm


It's interesting when you do the maths on how much energy is needed to get up a hill. If you're doing a 1000m ascent, at 10%, at 10kph, and weigh 70kg, your looking at putting out 250w for 1 hour. Or 3.57w/kg. That's well into trained person territory for power outputs.

Gives some perspective on how good some riders are when you see their straps times...

J

Ps, to. Maintain an Audax minimum of 15kph, on the same Hill requires 380w. Or 5.2w/kg...
Title: Re: How much power?
Post by: simonp on June 05, 2018, 01:39:35 pm
This is why I got dropped on the club run in Sunday. I’m not going to climb at 380W for long.

Once I gave up and did my own thing I was able to work harder on average because able to pace myself effectively. Got some PRs as well.

The above may have something to do with the fact there were only 5 people on the ride.
Title: Re: How much power?
Post by: zakalwe on June 05, 2018, 01:43:57 pm
I also want to test the claim that putting Techwind panniers on your front wheel can reduce drag by 7%  http://cycledifferent.com/angletech-techwind-panniers/

“The rear of the ANGLETECH TECHWIND’S™ are square profile to catch those tailwinds and blow you down the road.”

Is this a joke?  Have they never heard of vortex shedding/flow separation? ??? It's not only the leading surface that matters!

https://www.youtube.com/watch?v=O-FI6A8NRZI
Title: Re: How much power?
Post by: rdtrdt on June 05, 2018, 03:21:32 pm
I also want to test the claim that putting Techwind panniers on your front wheel can reduce drag by 7%  http://cycledifferent.com/angletech-techwind-panniers/

“The rear of the ANGLETECH TECHWIND’S™ are square profile to catch those tailwinds and blow you down the road.”

Is this a joke?  Have they never heard of vortex shedding/flow separation? ??? It's not only the leading surface that matters!

https://www.youtube.com/watch?v=O-FI6A8NRZI

Apostrophe criminals too. Sickening.
Title: Re: How much power?
Post by: Porkins on June 05, 2018, 05:49:38 pm
They claim it was proven in a wind tunnel test by the bloke who designed zzipper fairings. I've emailed them asking for more info but they never reply. I did buy the panniers tho, when I was in the US. I like the clean look. They have stiffened sides. If I buy a meter I'll try to do a comparison between crinkly panniers and smooth ones.
Title: Re: How much power?
Post by: gonzo on June 05, 2018, 06:12:53 pm
I have missed some of the aerodynamics claims having been out of the game for a while. I think that cycling must be one of the few places that looks to employ people who have a mixed speciality with aerodynamics and marketing.

I should add, that none of their specialities are aerodynamics. Or marketing. They probably are really good at rubbing their tummy while patting their head though.
Title: Re: How much power?
Post by: Porkins on June 06, 2018, 10:04:51 pm
I think the price of the shortened spindles will probably rule out the IQ2 for me. My Q factor is already 170mm, so there's no leeway...IQ2 would increase it to 202. A pair of IQ2 meters with a pair of Ultegra pedals is planned to cost £575. The Favero Assioma Duo can be had new for under £550 on ebay most weeks. With luck the IQ2's shipment will push down competitors' prices, so maybe I'll wait a year and get some 2nd hand Vector3 or Assioma for £300 or something. I dunno. These pedal prices are really pissing on some chips. I emailed IQ2 about it and they say there's no profit margin:
Quote
Please consider that we buy the original paddle from Shimano.
We fabricate the special titanium short paddle spindel.
After this we manually replace it for you so for you it's a unboxing, install and go riding. 

So the price actually is to low, but at this price point we can support the people that whant it,
but not go out off business because of it.
Title: Re: How much power?
Post by: quixoticgeek on June 06, 2018, 10:14:05 pm
I think the price of the shortened spindles will probably rule out the IQ2 for me. My Q factor is already 170mm, so there's no leeway...IQ2 would increase it to 202. A pair of IQ2 meters with a pair of Ultegra pedals is planned to cost £575. The Favero Assioma Duo can be had new for under £550 on ebay most weeks. With luck the IQ2's shipment will push down competitors' prices, so maybe I'll wait a year and get some 2nd hand Vector3 or Assioma for £300 or something. I dunno. These pedal prices are really pissing on some chips. I emailed IQ2 about it and they say there's no profit margin:
Quote
Please consider that we buy the original paddle from Shimano.
We fabricate the special titanium short paddle spindel.
After this we manually replace it for you so for you it's a unboxing, install and go riding. 

So the price actually is to low, but at this price point we can support the people that whant it,
but not go out off business because of it.

That makes sense, paying Dutch labour rates to install the new spindel is not going to be cheap. And they are adding titanium (which is expensive to machine). I can see why they are charging as much as they are. I can also see why some wouldn't want the extra expense.

Fortunately for me, I'm hoping to fit the IQ2 to a FSA crankset with a 146mm Q factor, which means I will only gain 8mm on what I cam currently riding.  I wonder if anyone else will come up with a similar design, but with a smaller Q factor...

J
Title: Re: How much power?
Post by: toontra on June 07, 2018, 10:18:02 am
Having ordered the IQ2's, all this talk of Q factors started to worry me so I've just measured the 2 bikes I'll most likely use them on.  The Cervelo is 145 - the Van Nic a bit wider at 155.  I reckon I should be OK with the additional 16mm on both of those as my tourer is a whopping 170 and doesn't seem to be an issue.

Should really have done this before ordering  :facepalm:
Title: Re: How much power?
Post by: Zed43 on June 07, 2018, 06:02:40 pm
Maybe you should budget for the Vector 3 if you want to be sure of buying something!
Just don't, they're horrible.

Battery life sucks; Garmins says 120 hours but the most I got out of a set of LR44's (the alkaline kind that everyone sells) is ~ 30 hours, in nice weather at that. Batteries are expensive (£8 a set) and fiddly to install. The left (master) pedal often loses connection with the right one, meaning only half the power is reported. Also lots of power spikes; I mean, really, 37400W????

Get a PowerTap G3 hub, or a Quarq DZero crankset. They just work.
Title: Re: How much power?
Post by: LEE on June 07, 2018, 06:18:08 pm
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

What does "low power high torque" mean?

Power is directly linked to Torque (it's sort of "Torques per Second" .  Same as Joules/sec).

I think you may mean low cadence, high power (but that translates to high torque, high power).

What the top pro riders have though is high cadence AND high torque...that results in superhuman power.  Froome spins quicker but I bet he still generates more torque on his pedal stroke than even the best club riders.
Title: Re: How much power?
Post by: zakalwe on June 07, 2018, 08:52:39 pm
Maybe you should budget for the Vector 3 if you want to be sure of buying something!
Just don't, they're horrible.

Battery life sucks; Garmins says 120 hours but the most I got out of a set of LR44's (the alkaline kind that everyone sells) is ~ 30 hours, in nice weather at that. Batteries are expensive (£8 a set) and fiddly to install. The left (master) pedal often loses connection with the right one, meaning only half the power is reported. Also lots of power spikes; I mean, really, 37400W????

Get a PowerTap G3 hub, or a Quarq DZero crankset. They just work.

Power2Max cranksets are pretty solid as well.
Title: Re: How much power?
Post by: rob on June 08, 2018, 02:16:13 pm
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

What does "low power high torque" mean?

Power is directly linked to Torque (it's sort of "Torques per Second" .  Same as Joules/sec).

I think you may mean low cadence, high power (but that translates to high torque, high power).

What the top pro riders have though is high cadence AND high torque...that results in superhuman power.  Froome spins quicker but I bet he still generates more torque on his pedal stroke than even the best club riders.

Phillipa York wrote an interesting piece about Froome in that he climbs at a high cadence but TTs at a low cadence.    There must be some sort of science behind it.
Title: Re: How much power?
Post by: chrisbainbridge on June 08, 2018, 08:01:09 pm
I wonder if he uses different crank lengths?
Title: Re: How much power?
Post by: simonp on June 08, 2018, 08:09:40 pm
I think it’s about inertia. There is less of a deceleration during the off phase of the pedal stroke on the flat vs on a hill. So you can push a bigger gear more easily on the flat.
Title: Re: How much power?
Post by: mattc on June 11, 2018, 03:15:02 pm
My gut response is that on a 45minute race you can stress your muscles more than on a 4-6hour stage.

(i.e. lower cadence is more fatiguing, but gives slightly better power - assuming you train for it!)

I don't think there's much hard science to support this, but it fits with stuff that I vaguely recall reading in recent years - and with my totally reliable Mattometer of course  :smug:
Title: Re: How much power?
Post by: Cudzoziemiec on June 20, 2018, 02:40:21 pm
My gut response is that on a 45minute race you can stress your muscles more than on a 4-6hour stage.

(i.e. lower cadence is more fatiguing, but gives slightly better power - assuming you train for it!)

I don't think there's much hard science to support this, but it fits with stuff that I vaguely recall reading in recent years - and with my totally reliable Mattometer of course  :smug:
So it's Mattomatically possible (just like England winning the World Cup).
Title: Re: How much power?
Post by: CrazyEnglishTriathlete on June 28, 2018, 01:46:38 pm
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.

I agree with this.

I mentioned in another thread that I'm a relatively recent cycling returnee, and I've found the data now available via power measurements and Strava more interesting than I'd expected!

I ride in the Peak District, which has no shortage of cyclists, so there's plenty of steep hills in Strava that thousands upon thousands have ridden including plenty of very talented cyclists. My last FTP test was ~3.2 w/kg, and I'm finding that on the steeper hills this power-to-weight has me doing times that are roughly around the top 20%-ish region.

My current goal is to get to ~3.5 w/kg, which I estimate would be approx where I was a few years back when riding pretty well. I rode a bunch of short hilly audaxes back then and would tend to be in the front group of climbers, only occasionally coming across a fellow audaxer climbing significantly faster, which ties in well with your experience at 3.6 w/kg.

At 4w/kg, I can see how very few audaxers could live with you on hills, considering the audaxing demographic and the long distance focus. I don't think I have the appetite (or maybe ability?) for the gruelling punishment it'd require, but if I somehow did achieve 4w/kg I've promised myself a new bike outfitted with Di2, dual-sided power meter and hydraulic disc brakes, etc, fairly safe in the knowledge I won't be paying out...

One of the fascinating things about the Strava data is the vast gulf it exposes lying between someone like me who's reasonably fit (for my age!) but with no innate talent, and the fast people who post times that are mind blowing. It's not just the handful pro-level names, but a whole swathe of extremely fit and talented cyclists posting times that I can only marvel at. Where did talent + hard work ever get anyone?  ;D

I love like the reality-check this all provides. I've always thought testers were mental - which they clearly are - but maybe I'm beginning to get a glimpse of what's in their heads?

I rode up the Hochwald 3.1km @10% which was a good point at which to test my watts/kg - 311Watts for 17 minutes, 83kg.  My bike (unknown to me at the time had a crack in the frame which could have caused some power leakage, although it wasn't creaking much up the hill).  So that gives 3.75W/kg.  There are some AUK anciens that drop me on hills, but I'm usually somewhere near the front but not at the front on hilly events, especially ones with longer hills, so I reckon that you are right with 4W/kg being a level which only a small proportion of randonneurs exceed. 
Title: Re: How much power?
Post by: zigzag on June 28, 2018, 02:29:58 pm
I rode up the Hochwald 3.1km @10% which was a good point at which to test my watts/kg - 311Watts for 17 minutes, 83kg.  My bike (unknown to me at the time had a crack in the frame which could have caused some power leakage, although it wasn't creaking much up the hill).  So that gives 3.75W/kg.  There are some AUK anciens that drop me on hills, but I'm usually somewhere near the front but not at the front on hilly events, especially ones with longer hills, so I reckon that you are right with 4W/kg being a level which only a small proportion of randonneurs exceed.

assuming that:
* the pacing was consistent
* the power was measured accurately
* the same effort could be sustained for another 3min

that gives power-to-weight of 3.37w/kg (311 x 0.9 / 83). i found that it is incredibly hard to raise the ftp after hitting one's "natural plateau" every little gain requires enormous amount of work..
Title: Re: How much power?
Post by: LMT on June 28, 2018, 07:57:42 pm
I rode up the Hochwald 3.1km @10% which was a good point at which to test my watts/kg - 311Watts for 17 minutes, 83kg.  My bike (unknown to me at the time had a crack in the frame which could have caused some power leakage, although it wasn't creaking much up the hill).  So that gives 3.75W/kg.  There are some AUK anciens that drop me on hills, but I'm usually somewhere near the front but not at the front on hilly events, especially ones with longer hills, so I reckon that you are right with 4W/kg being a level which only a small proportion of randonneurs exceed.

assuming that:
* the pacing was consistent
* the power was measured accurately
* the same effort could be sustained for another 3min

that gives power-to-weight of 3.37w/kg (311 x 0.9 / 83). i found that it is incredibly hard to raise the ftp after hitting one's "natural plateau" every little gain requires enormous amount of work..

easier to lose 13kg.
Title: Re: How much power?
Post by: CrazyEnglishTriathlete on July 03, 2018, 02:24:59 pm
I rode up the Hochwald 3.1km @10% which was a good point at which to test my watts/kg - 311Watts for 17 minutes, 83kg.  My bike (unknown to me at the time had a crack in the frame which could have caused some power leakage, although it wasn't creaking much up the hill).  So that gives 3.75W/kg.  There are some AUK anciens that drop me on hills, but I'm usually somewhere near the front but not at the front on hilly events, especially ones with longer hills, so I reckon that you are right with 4W/kg being a level which only a small proportion of randonneurs exceed.

assuming that:
* the pacing was consistent
* the power was measured accurately
* the same effort could be sustained for another 3min

that gives power-to-weight of 3.37w/kg (311 x 0.9 / 83). i found that it is incredibly hard to raise the ftp after hitting one's "natural plateau" every little gain requires enormous amount of work..

Looking at the Garmin the speed was consistent.  Time was right to the second as I looked at the timer on the Garmin on bottom and top, both very sharply defined and the height gain was taken from spot heights.  The power is based on a British Cycling calculator using distance, altitude, my weight 83kg + bike weight 10kg.  I wasn't on the point of collapse at the top - the presence of a visible col over the last few hundred meters was clearly a motivating factor - but if it had been a false summit I think I would have kept going at the same cadence for quite a time further.  Wasn't sure where the 0.9 came in the above formula.

Possibly the presence of someone overtaking me on an e-bike provided a motivating factor.  It certainly surprised me as I became aware of a rider passing me half way up  :facepalm:
Title: Re: How much power?
Post by: LMT on July 03, 2018, 10:18:31 pm
I rode up the Hochwald 3.1km @10% which was a good point at which to test my watts/kg - 311Watts for 17 minutes, 83kg.  My bike (unknown to me at the time had a crack in the frame which could have caused some power leakage, although it wasn't creaking much up the hill).  So that gives 3.75W/kg.  There are some AUK anciens that drop me on hills, but I'm usually somewhere near the front but not at the front on hilly events, especially ones with longer hills, so I reckon that you are right with 4W/kg being a level which only a small proportion of randonneurs exceed.

assuming that:
* the pacing was consistent
* the power was measured accurately
* the same effort could be sustained for another 3min

that gives power-to-weight of 3.37w/kg (311 x 0.9 / 83). i found that it is incredibly hard to raise the ftp after hitting one's "natural plateau" every little gain requires enormous amount of work..

Looking at the Garmin the speed was consistent.  Time was right to the second as I looked at the timer on the Garmin on bottom and top, both very sharply defined and the height gain was taken from spot heights.  The power is based on a British Cycling calculator using distance, altitude, my weight 83kg + bike weight 10kg.  I wasn't on the point of collapse at the top - the presence of a visible col over the last few hundred meters was clearly a motivating factor - but if it had been a false summit I think I would have kept going at the same cadence for quite a time further.  Wasn't sure where the 0.9 came in the above formula.

Possibly the presence of someone overtaking me on an e-bike provided a motivating factor.  It certainly surprised me as I became aware of a rider passing me half way up  :facepalm:

Coefficient of friction innit.
Title: Re: How much power?
Post by: mrcharly-YHT on December 20, 2018, 04:33:59 pm
Not about cycling, not really . . .

OK, so a few weeks ago I was using a hand crank exercise machine. With a variable setting ('Rolling hills') I could sustain 180W, and do 30s 'sprints' of 300W. 20 min sessions.

I'm going to a different gym and using a cross trainer (I've been doing a bit of jogging, 5km in about 25-26min). According to the cross-trainer, I'm sustaining 160W, maxing at 240W.

The cross-trainer is killing me.

This doesn't make sense. The cross-trainer is using my legs and arms. My legs are dying. I'm putting out fewer watts, heart rate about 170. I don't have the arms of a beast!
Title: Re: How much power?
Post by: Kim on December 20, 2018, 04:35:05 pm
I'll guess that neither device had a calibration certificate...
Title: Re: How much power?
Post by: mrcharly-YHT on December 20, 2018, 04:55:40 pm
I'll guess that neither device had a calibration certificate...
I did wonder about that. They are fairly wide variations though!
Monday I used one machine at the gym and had a hard workout. Wed used a different one, same settings and was dying. Either I was tired or the machines were serving different workloads on the same settings.
Title: Re: How much power?
Post by: simonp on December 20, 2018, 05:13:20 pm
You’re supporting your weight on your legs on the cross trainer. I’m not convinced it’s a very efficient motion either. Also more muscle is active for the same power => might be your hr is higher. I experience similar on a rowing machine - same watts results in a higher heart rate.