power to weight
Comments
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It's not about the bike0
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I don't think that PtW would be a very useful measurement if it included the bike, especially if you have more than one, as it would be different from bike to bike unless they all weighed the same (you could instantly improve the ratio by swapping to a lighter bike too though
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craprider wrote:Just a quick one, when people talk about power to weight ratio does that include the bike?
just wondered.
For any useful calculation, yes it does. It is essentially the amount of power in watts that it takes to shift a given weight along and up and given distance and height. That given weight includes weight of bike, rider and clothing, and any water in the bottles!
See link:
http://bikecalculator.com/0 -
cheers one of. thats what i was thinking, as they are so specific that much (even though it seems little) could make a massive difference.0
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oneof1982 wrote:craprider wrote:Just a quick one, when people talk about power to weight ratio does that include the bike?
just wondered.
For any useful calculation, yes it does. It is essentially the amount of power in watts that it takes to shift a given weight along and up and given distance and height. That given weight includes weight of bike, rider and clothing, and any water in the bottles!
See link:
http://bikecalculator.com/
When you see numbers quoted for Pro cyclists it won't include the bike.More problems but still living....0 -
amaferanga wrote:oneof1982 wrote:craprider wrote:Just a quick one, when people talk about power to weight ratio does that include the bike?
just wondered.
For any useful calculation, yes it does. It is essentially the amount of power in watts that it takes to shift a given weight along and up and given distance and height. That given weight includes weight of bike, rider and clothing, and any water in the bottles!
See link:
http://bikecalculator.com/
When you see numbers quoted for any cyclist it won't include the bike.
Fixed.0 -
The Mad Rapper wrote:amaferanga wrote:oneof1982 wrote:craprider wrote:Just a quick one, when people talk about power to weight ratio does that include the bike?
just wondered.
For any useful calculation, yes it does. It is essentially the amount of power in watts that it takes to shift a given weight along and up and given distance and height. That given weight includes weight of bike, rider and clothing, and any water in the bottles!
See link:
http://bikecalculator.com/
When you see numbers quoted for any cyclist it won't include the bike.
Fixed.
Not sure I get this. Two ways of measuring, either directly, using SRM, data generated will obviously include anything that is being pushed, or by observation and calculation. Time taken over a given distance and climb as observed will obviously include bike etc.
Reality is this may be a mute point, as bikes all weight 6.8kg, and clothing will be minimal.
Other big issue is aerodynamic drag.0 -
oneof1982 wrote:The Mad Rapper wrote:amaferanga wrote:oneof1982 wrote:craprider wrote:Just a quick one, when people talk about power to weight ratio does that include the bike?
just wondered.
For any useful calculation, yes it does. It is essentially the amount of power in watts that it takes to shift a given weight along and up and given distance and height. That given weight includes weight of bike, rider and clothing, and any water in the bottles!
See link:
http://bikecalculator.com/
When you see numbers quoted for any cyclist it won't include the bike.
Fixed.
Not sure I get this. Two ways of measuring, either directly, using SRM, data generated will obviously include anything that is being pushed, or by observation and calculation. Time taken over a given distance and climb as observed will obviously include bike etc.
Reality is this may be a mute point, as bikes all weight 6.8kg, and clothing will be minimal.
Other big issue is aerodynamic drag.
The thing you all seem to be forgetting is that W/Kg readings are taken indoors, sometimes on rigs or wattbikes (which weigh a ton), and always when stationary (on a roller, turbo, or treadmill). So the weight of the bike is completely irrelevant. W/Kg are a measurment of the power a rider can produce relative to his or her weight. Said power is being put directly into the cranks, and measured there normally, so again, the weight of the bike is largely irrelevant and not taken into account. Obviously two riders with the same W/Kg output, riding two bikes, one heavier than the other, will see a difference in performance. But even if both riders were riding exactly the same bikes you would still see a difference, as one may be a sprinter and the other a climber and each would react differently to certain environments.0 -
The Mad Rapper wrote:amaferanga wrote:oneof1982 wrote:craprider wrote:Just a quick one, when people talk about power to weight ratio does that include the bike?
just wondered.
For any useful calculation, yes it does. It is essentially the amount of power in watts that it takes to shift a given weight along and up and given distance and height. That given weight includes weight of bike, rider and clothing, and any water in the bottles!
See link:
http://bikecalculator.com/
When you see numbers quoted for any cyclist it won't include the bike.
Fixed.
Changed, not fixed, because it wasn't wrong.
In some cases it does make sense to include the weight of the bike and gear. But usually numbers are quoted as the riders weight only.More problems but still living....0 -
Maverick54 wrote:
The thing you all seem to be forgetting is that W/Kg readings are taken indoors, sometimes on rigs or wattbikes (which weigh a ton), and always when stationary (on a roller, turbo, or treadmill). So the weight of the bike is completely irrelevant. W/Kg are a measurment of the power a rider can produce relative to his or her weight. Said power is being put directly into the cranks, and measured there normally, so again, the weight of the bike is largely irrelevant and not taken into account. Obviously two riders with the same W/Kg output, riding two bikes, one heavier than the other, will see a difference in performance. But even if both riders were riding exactly the same bikes you would still see a difference, as one may be a sprinter and the other a climber and each would react differently to certain environments.
Not necessarily, as most pros will use powermeters installed to the bike and will do little to no indoor or stationary testing.0 -
TONY.M wrote:Maverick54 wrote:
The thing you all seem to be forgetting is that W/Kg readings are taken indoors, sometimes on rigs or wattbikes (which weigh a ton), and always when stationary (on a roller, turbo, or treadmill). So the weight of the bike is completely irrelevant. W/Kg are a measurment of the power a rider can produce relative to his or her weight. Said power is being put directly into the cranks, and measured there normally, so again, the weight of the bike is largely irrelevant and not taken into account. Obviously two riders with the same W/Kg output, riding two bikes, one heavier than the other, will see a difference in performance. But even if both riders were riding exactly the same bikes you would still see a difference, as one may be a sprinter and the other a climber and each would react differently to certain environments.
Not necessarily, as most pros will use powermeters installed to the bike and will do little to no indoor or stationary testing.
The powermeter measures the power not the weight. You get the ratio by dividing the power by your own weight in kg. It's a measure of the athlete not the bike.Scottish and British...and a bit French0 -
dulldave wrote:TONY.M wrote:
Not necessarily, as most pros will use powermeters installed to the bike and will do little to no indoor or stationary testing.
The powermeter measures the power not the weight. You get the ratio by dividing the power by your own weight in kg. It's a measure of the athlete not the bike.
Thanks for that Dave, I had absolutely no idea that a bike mounted PM does not measure weight. 0 -
I had absolutely no idea that a bike mounted PM does not measure weight
Otherwise it would be called a weight meter aka a pair of scales............0 -
dulldave wrote:It's a measure of the athlete not the bike.
This.
How many Watts can you produce per kilo of body weight. That's all it is.
If you're trying to calculate W/Kg from timing a rider on a climb then you'll factor in the weight of the bike.Warning No formatter is installed for the format0 -
No $hit.itisaboutthebike wrote:I had absolutely no idea that a bike mounted PM does not measure weight
Otherwise it would be called a weight meter aka a pair of scales............
That's right. Although I do dislike hearing of riders trying to calculate power to weight by timing rides or climbs as wind affects things so much without being aware of it.No tA Doctor wrote:If you're trying to calculate W/Kg from timing a rider on a climb then you'll factor in the weight of the bike.
I have had some slow times up known climbs although power was good and some great times with power being lower, the wind affects things so much even when it does not seem windy and without the SRM I would not have been aware this.
Cheers0 -
I was only after a yes no......
cheers all!0 -
If you want to compare actual performances you should really include the weight of the bike..
Example, rider A weighs 100 kg and produces 500 W on a specific climb. Rider B weighs 50 kg and produces 250 W, and has the same aero drag and bike (6.8kg) as A. If you exclude bike weight you would perhaps conclude that they go equally fast as they both perform 5W/kg. But if you include the bike weight you realise that rider A would be the fastest up the climb. He would have a W/"total weight" of 4,68, versus rider B with 4,40...0 -
Crack on lads, we are all having a good laugh reading this
Best thread in pro race for a good while.0
