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2006-07-29 1:40 AM

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Subject: Watts
Curious if anyone can explain how watts translates into power/weight/energy used? I'm not sure what it means if someone says you will gain 1 to 5 watts on your ride.


2006-07-29 3:05 AM
in reply to: #496791

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Subject: RE: Watts

I'm not entirly sure if this is what you mean but...

Watts are a measure of power, which is the work done or energy transfered in a certain time.

Cyclists who use power meters are measuring the amount of work they are doing in watts and just like you can find your lactate HR you can also measure the maximum sustainable power using a power meter.  If, over time, this number goes up then it means that they have increased their lactate threshold and so are able to sustain more power, which means they can go faster.  I'm not sure but maybe this is what they mean when they say you will gain 1 - 5 watts (although it takes longer periods of time than just one ride to increase your power significantly).

2006-07-29 3:09 AM
in reply to: #496791

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Subject: RE: Watts
I have been leeoking at buying the Zipp 404's for some time now. I was reading in their as where it mentioned an increase, but wasn't sure how that would translate for me.
2006-07-29 3:45 AM
in reply to: #496791

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Subject: RE: Watts

What they mean here is that due to the good aerodynmics of the wheels it would be like riding with a higher power output.  In other words they make you faster.

2006-07-29 5:27 AM
in reply to: #496791

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Subject: RE: Watts
So does the watts to speed ratio change with every rider, or is it static?
2006-07-29 7:12 AM
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Subject: RE: Watts

corndogcaun - 2006-07-29 1:40 AM Curious if anyone can explain how watts translates into power/weight/energy used? I'm not sure what it means if someone says you will gain 1 to 5 watts on your ride.
Power to weight ratio is a way to compare different riders (heights & weight) in the same level.

For instance let’s take 180 pounds rider, in general he should produce more power than a 139 pounds (my weight ). If you compare both of their Power Threshold (power they can sustain for 1 hr) it might be misleading because the 1st rider due to height and/or weight might have a higher threshold (i.e. 300 watts) while the other one might have a lower (my threshold is around 255 watts). If you want to compare both riders, you can use the power to weight ratio

>> covert both riders weight to kilos and divide power by weight. i.e. 1st rider power to weight ratio based on 180 pounds and 300 threshold watts: 3.66 and 2nd rider (me) power to weight ratio based on 139 pounds and 255 threshold watts: 4.03. In this case even when rider 1 has a higher LT when you consider how much power each rider can produce per kilogram the 2nd has a higher power output…



2006-07-29 7:20 AM
in reply to: #496791

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Subject: RE: Watts
opps I posted before finishing. Anyway if you determine that your power threshold is "x" then in "theory" if you gain benefits of saving energy from your tri-bike (ride with a lower CdA) and equipment (aero wheels, aero helmet, clothing, etc) in means that you “could” ride using the same power output at a faster speed or at the same speed conserving energy (watts).

Here is a link with lots of power info: http://www.cyclingpeakssoftware.com/power411/

2006-07-29 7:26 AM
in reply to: #496791

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Subject: RE: Watts
Thanks, I really appreciate the info. You answered my question.
2006-07-29 10:18 AM
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Subject: RE: Watts

If you want to geek out on power calculations, check out http://analyticcycling.com/.  For example, you can run this tool http://analyticcycling.com/ForcesPower_Page.html to calculate how many watts you need to generate to achieve a given speed.  Of course, you'll see there are numerous factors that figure into the calculation, many of which will just be estimates for you, but it's interesting to play around with anyway.

-Steve

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