Will I ever be able to climb with lightweights?

DaveyL

Power and weight are the key issues - what's the point in carrying out a bit of arithmetic on one of them (weight, sorry, mass) to get another number?

What if I create a new metric, let's call it Power Index Set to Height (PISH) which is your functional threshold power divided by your height in metres, squared. Now when anyone says that power is important, I can say, "Well have you considered your PISH factor? Power's a component of that so it must be important"....

Anonymous

Because height isn't a factor in power to weight ratio, but may become a factor when taking into account Cda...

a_n_t

liversedge wrote:

here are the BMIs for Lance Armstrong, Miguel Indurain. Mark Cavendish and Robbie McEwen ...

results, in no particular order are: 22.8, 22.6, 22.5, 22.9

hmmmmm, i just found out mine is 20.5!

SOMEONE PASS ME A DOUGHNUT!!!!! or a saw?

BeaconRuth

Thanks NapoleonD and Doyler78, I'm glad a few others are talking sense.

SteveR_100Milers wrote:

That's a fair comment Ruth, my point was poorly made that BMI is a crude tool at predicting your relative obesity.

I agree with you there - although unless someone has been working-out a lot in a gym or has some other reason to be exceptionally heavy for their height, then I don't think it's as bad an indicator as people like to make out. People are far too quick to say "Jonah Lomu has a BMI of 32, therefore although all I've done all my life is sit on a couch and eat pizza, I'm not going to let it bother me that my BMI is 32 because it must be meaningless." It isn't meaningless. Mr Couch Potato IS very heavy for his height. Whether that is a problem or not is another matter. BMI doesn't say whether it's a problem but it is a hard, factual measure.

If BMI is not used for that purpose then what else can it tell you of any importance to cycling?

Well, as a crude indicator of whether someone will be good at climbing hills?

The actual calculation as a ratio of size (height) and weight is another way of expressing the difficulty of getting over hills, but ultmately, you might as well simply use power / weight expressed in watts/kilo as you rightly say it doesnt matter whether its fat/muscle/bone or bike, it all needs lugging over a hill. What height you are makes no difference surely?

You might as well simply use power.................... but only if you know your power. The OP didn't give his power, so I used the information he gave - his height and his weight. Most people don't know their power so using their BMI is a crude alternative which is accessible to anyone. That's all. I'm not saying BMI is better or nearly as good as power to weight.

Here's an interesting thought I have had many times, and I think I partly know the answer. cycling predominatly aerobically does cause hypertrophy in the leg muscles, though not as much as working out in the gymn. (although from observation so many cyclists seem to have large quads compared to non cyclists, which might well be because the rest of their bodies is disproprtionaly smaller). Therefore, what is the power v mass relationship in a muscle? I am assuming the answer partly lies in the fact that the leg muscles do not in fact grow much in size (therefore mass? unless mitochondria and blood capilliaries are significant)

That is an interesting thought and my mind immediately goes to Vicky Pendleton. There is massive power there but she's not built like a brick wall like many of her rivals!

DaveyL wrote:

Power and weight are the key issues - what's the point in carrying out a bit of arithmetic on one of them (weight, sorry, mass) to get another number?

Because most people don't know their power output so they can't calculate their power to weight ratio. And your BMI does give a broad indication of what might be a 'reasonable' weight to enable you to be a good climber.

Ruth

ugo.santalucia

holmeboy wrote:

Been doing a lot of miles for the last 2 years now including a lot of hills, the Question I've got to ask you experts is will I ever be able to keep up with a 10 stone cyclist (I'm 13 and a bit) going up hill into winds etc? I can do it for a while with extreme effort but eventually get dropped. Don't really see me losing much more weight, I'm 6ft of medium build.

:oops: :twisted: :roll: 8)

3 stones means 19 Kg excess, assuming your mates can produce 4-5 W per Kilo of bodyweight on a short British climb, menas you need nearly 100 Watt of power output in excess of your mates just to stay with them. It's a big ask.
My answer is no, you'll never be able, unless you train twice as hard as they do.
That said, you can probably stay with them on a less steep climb, up to 4-5% gradient, where the power/weight ratio is not the only decisive factor.
Only heavy cyclist I recall to be able to stay with the best was Indurain, but he had exceptionally high VO2 and enormous power output

Anonymous

So you can compare yourself with others of a different height.

SteveR_100Milers

"Ruth"And your BMI does give a broad indication of what might be a 'reasonable' weight to enable you to be a good climber.

Sorry I missed that point from the original post d'oh! Agree.

BTW I have just bought a *proper* TT bike and pointy helmet, so no excuses this year...it's made me re-think sessions on the turbo at least for the time being

BeaconRuth

SteveR_100Milers wrote:

BTW I have just bought a *proper* TT bike and pointy helmet, so no excuses this year...it's made me re-think sessions on the turbo at least for the time being

Super! What have you got? And how has it made you re-think your turbo sessions?

Ruth

jimycooper

i'm not sure bmi has anything to do with it on climbs.
my bmi is 19.2 and im nothing special when i hit the hills. it's totaly power to wait ratio if you forget about the wind which wouldn't even make much of a differnce when going at a climbing pace.

a_n_t

jimycooper wrote:

im nothing special when i hit the hills. it's totaly power to wait ratio .

well if you're going to hang around!

jimycooper

a_n_t wrote:

jimycooper wrote:

im nothing special when i hit the hills. it's totaly power to wait ratio .

well if you're going to hang around!

sorry, only looked at the last page. :oops:

a_n_t

jimycooper wrote:

sorry, only looked at the last page. :oops:

I'm wasted here!

power to WAIT geddit?

BeaconRuth

I think you should go and eat a few more doughnuts, A_N_T and do some productive work on your BMI. It's obvious spelling isn't Jimy's strong suit.

Ruth

a_n_t

well, asda do make some nice custard filled ones! :P

ob

Apologies if anyone's posted this before, bue there's quite an interesting article on wikipedia.

http://en.wikipedia.org/wiki/Bicycle_performance

At one point it gives you the calculation of power required and how this relates to mass, gravity, aerodynamics, gradient, etc.

I've not got my maths hat on this morning, but i don't think it's as simple as saying "if you're 20kg heavier, and you produce 5W/kg, you therfore need to produce 100W more than the lighter person to match them".

Alex_Simmons/RST

ob wrote:

Apologies if anyone's posted this before, bue there's quite an interesting article on wikipedia.

http://en.wikipedia.org/wiki/Bicycle_performance

At one point it gives you the calculation of power required and how this relates to mass, gravity, aerodynamics, gradient, etc.

I've not got my maths hat on this morning, but i don't think it's as simple as saying "if you're 20kg heavier, and you produce 5W/kg, you therfore need to produce 100W more than the lighter person to match them".

On a steeper climb, then the speed of two riders producing 5W/kg will be almost the same. So yes, it is that simple.

That's because the speed on such climbs is relatively low and steady (i.e. no acceleration/changes in kinetic energy), so the impact of rolling resistance and aero drag is reduced significantly, making gravity (or the change in potential energy) the primary resistance.

Once the terrain flattens a little (or heads downhill), then the relationship no longer holds.

Refer to the chart I posted earlier in this thread.:
http://www.bikeradar.com/forums/viewtop ... 5#15107875

That is generated using the equations of motion for a cyclist as per Martin et al:

ob

That's quite an interesting graph. Do you know what it does beyond 10%? It looks like the lines converge and will bottom out at 3 m/s regardless of gradient.

Not that I'm considering challenging anyone to a 10% climb!

whyamihere

Alex_Simmons/RST wrote:

That equation doesn't work. The PWB term has units of d^2/t^2, which isn't power. It should have md^2/t^3, as all the other terms have. It requires weight and inverse time to be applied in order to be valid.

Alex_Simmons/RST

whyamihere wrote:

That equation doesn't work. The PWB term has units of d^2/t^2, which isn't power. It should have md^2/t^3, as all the other terms have. It requires weight and inverse time to be applied in order to be valid.

Well, here's the more detailed explanation of that particular term from the original paper:



I think you'll find that the wheel bearing friction component was a practical equation derived from actual data, rather than a theoretical one and that the "missing" units are probably embedded within the constants so derived.

In any case, contribution of wheel bearing friction is very small and at the speeds we are talking about in going uphill, amounts to less than 1 watt.

Finally, I should add that the equations shown have been tested against actual power meter data and have been shown to reliably predict actual performance.

Alex_Simmons/RST

ob wrote:

That's quite an interesting graph. Do you know what it does beyond 10%? It looks like the lines converge and will bottom out at 3 m/s regardless of gradient.

Not that I'm considering challenging anyone to a 10% climb!

Well there are some "simplifications" in the equations to the extent that gradients beyond 10% probably need a little more maths to be included*.

I would suggest however that the line will continue towards zero velocity as gradient tips upwards. Hence the curve you see happen at lower gradients is not continued.


* That's because one of the terms which is in the full equations:
COS[TAN^-1(GR)] = 0.995 - 1.000 for gradients up to 10%, so that is considered for all intensive purposes to = 1, enabling a slight simplication of the formula.

Mind you, one of the paper's authors posts here occasionally, maybe he could shed some light on it for us.

whyamihere

Alex_Simmons/RST wrote:

whyamihere wrote:

That equation doesn't work. The PWB term has units of d^2/t^2, which isn't power. It should have md^2/t^3, as all the other terms have. It requires weight and inverse time to be applied in order to be valid.

Well, here's the more detailed explanation of that particular term from the original paper:



I think you'll find that the wheel bearing friction component was a practical equation derived from actual data, rather than a theoretical one and that the "missing" units are probably embedded within the constants so derived.

In any case, contribution of wheel bearing friction is very small and at the speeds we are talking about in going uphill, amounts to less than 1 watt.

Finally, I should add that the equations shown have been tested against actual power meter data and have been shown to reliably predict actual performance.

That explanation does make it make sense (torque contains the missing units, so they will be expressed in the constants). Thanks for clearing it up.

a_n_t

and here's me thinking Cd meant Custard doughnuts :roll:

SteveR_100Milers

BeaconRuth wrote:

SteveR_100Milers wrote:

BTW I have just bought a *proper* TT bike and pointy helmet, so no excuses this year...it's made me re-think sessions on the turbo at least for the time being

Super! What have you got? And how has it made you re-think your turbo sessions?

Ruth

A focus izalco chrono, just looking for some nice blingy carbon deep section wheels on the cheap!
Spending a shade over £2k focuses the mind somewhat when sitting on the turbo, how long that will last I don't know. One thing I am going to do though that i have not done before is at least weekly ride our club 10 course on it to "tune" the set up and position, so I should have a good idea what I can expect to achieve this year. Structured goal orientated training...now that's a first!

First event is a 2 up 25 on 1st March, and I've pencilled in about 20 open events this year...let's see if the enthusiasm can stretch all the way till September for the welsh 12 hour

Pirateman

Through out this thread you all mention power to weight ratios and then go on to say what weight you are. When speaking about power the magical figure is 3w to 6w/kg. But is there a power figure that we should be looking at to reach. Last October I did a Sportest and all I could manage was 217watts. So should I just put my bike in the broom wagon before a sportive so save all the heartache

Height 5.7 (170cm) - Weight 8.11 (56kg) - power to weight 3.73watts/kg

(Tomorrow we ride)

liversedge

nmcgann

SteveR_100Milers wrote:

BeaconRuth wrote:

SteveR_100Milers wrote:

BTW I have just bought a *proper* TT bike and pointy helmet, so no excuses this year...it's made me re-think sessions on the turbo at least for the time being

Super! What have you got? And how has it made you re-think your turbo sessions?

Ruth

A focus izalco chrono, just looking for some nice blingy carbon deep section wheels on the cheap!
Spending a shade over £2k focuses the mind somewhat when sitting on the turbo, how long that will last I don't know. One thing I am going to do though that i have not done before is at least weekly ride our club 10 course on it to "tune" the set up and position, so I should have a good idea what I can expect to achieve this year. Structured goal orientated training...now that's a first!

First event is a 2 up 25 on 1st March, and I've pencilled in about 20 open events this year...let's see if the enthusiasm can stretch all the way till September for the welsh 12 hour

I'd recommend you use your TT bike on the turbo and do all your training down on the aerobars. I made the mistake on not doing that last winter and then struggled for ages with getting the power down on the road in race position.

Neil

ugo.santalucia

Pirateman wrote:

Through out this thread you all mention power to weight ratios and then go on to say what weight you are. When speaking about power the magical figure is 3w to 6w/kg. But is there a power figure that we should be looking at to reach. Last October I did a Sportest and all I could manage was 217watts. So should I just put my bike in the broom wagon before a sportive so save all the heartache

Height 5.7 (170cm) - Weight 8.11 (56kg) - power to weight 3.73watts/kg

(Tomorrow we ride)

Well, the numbers I was quoting are for a typical short british climb, a mile or so. If you can produce 3.7 W/Kg on a long alpine climb, I think it is very respectable.
Another way to measure the climbing performace, which seems to make more sense, but doesn't relate directly to body weight is the average vertical speed.
I manage in excess of 1100 mt per hour on a short climb, but alpine climbs such as this
http://ridewithugo.xtreemhost.com/scalaro.html
which is my local back in italy, well, I manage about 900-950 mt/h, more or less.
I can't be bothered to calculate what that means in W/Kg, as an accurate calculation should take into account how much weight you're carrying on your bike eg. water bottles, saddle bag, not to speak about shoes and that Pantani-like bandana. But I reckon it's probably somewhere between 3.5 and 4, maybe closer to 4 in the British scenario

fuzzynavel

Pirateman wrote:

Through out this thread you all mention power to weight ratios and then go on to say what weight you are. When speaking about power the magical figure is 3w to 6w/kg. But is there a power figure that we should be looking at to reach. Last October I did a Sportest and all I could manage was 217watts. So should I just put my bike in the broom wagon before a sportive so save all the heartache

Height 5.7 (170cm) - Weight 8.11 (56kg) - power to weight 3.73watts/kg

(Tomorrow we ride)

Approx 3 watts/kg is all I can put out but then I am nearly double your weight! (95kg)

I presume that your test was 1 hour duration. if so then you should look at the FTP column in the chart given. You weigh in around a mid field cat 3 racer but in reality races are rarely about who has the most power. Tactics, weather, other people and a bit of luck come into it too.

SteveR_100Milers

nmcgann wrote:

I'd recommend you use your TT bike on the turbo and do all your training down on the aerobars. I made the mistake on not doing that last winter and then struggled for ages with getting the power down on the road in race position.

Neil

is exactly what I plan to do.

Pirateman

Liversedge

Thanks for the info. I have not worked out what the 5s means at the head of the first coloum. I am sure it is obivious but

---

:idea:

Thanks to all who replied on my comment. All helpful to understand it more

(Tomorrow we ride with Pantani - Bandana)