Watts/Kilo v Watts

penski

Hello,

Could anybody advise - to sustain the same pace between a group of riders, would the Wattage output need to match or the Watts/Kg.

I.e Will everybody outputting 200W be travelling at the same pace, or everybody travelling at 3W/KG?

I'm guessing its Watts..

ozzzyosborn206

its not that simple, how big a hole you are punching through the air also needs to be taken into account. On the flat its more likely to be watts, on a climb w/kg but neither will be exactly the same

buckmulligan

Yes, precisely what Ozzy said.

The relationship between power output and speed is much more complicated than what you suggest.

On the flat, the only detriment that weight will have will be to increase your rolling resistance (which is only a small part of your total drag) so total power output will be most important.

Going uphill, gravity becomes a significant portion of the drag and is heavily dependent on weight, so your power-to-weight ratio will be most important.

The links below are a good introduction to the physics behind it if you're interested; basically, if you can't increase your power, you can work on decreasing your CdA to get faster on the flat, or decreasing your weight to get faster going uphill. Simple.

http://www.slowtwitch.com/Tech/The_Physics_of_Moving_a_Bike_163.html
http://www.gribble.org/cycling/power_v_speed.html

penski

Thanks for the responses.

My reason for asking was because I wanted to go riding with an old friend, and wanted to see roughly where we were at in terms of ability.

ozzzyosborn206

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19763917#p19763917]Penski[/url] wrote:

Thanks for the responses.

My reason for asking was because I wanted to go riding with an old friend, and wanted to see roughly where we were at in terms of ability.

I think you may be over thinking things, unless one of you is miles better than the other which i doubt if you both have power meters you should be able to go for a decent ride without either of you feeling like you compromising the others ride too much.