## W/kg

A light bike doesn't replace good fitness.

Moderator: Moderator Team

Kermithimself
Posts: 992
Joined: Sat Jun 02, 2007 12:48 pm
Location: Denmark
A friend of mine recently asked me a question that I was uncertain of, so I'll try it here with all the brains.

If rider A and B rides up a climb in exactly the same time, and with the exact same weather conditions, will they have the same Watt/kg? If rider A weighs 70 kg, and rider B 80, and rider a rides with a powermeter. At the top rider A has had an average wattage of say 300 watts. This equals to 4,28 Watts/kg. Would you be able to take rider B and say 4,28 x 80 = 342 watts?
------------
If you dream of being famous - think of what birds do to statues.
Instagram: https://www.instagram.com/kermithimself/

darkblue08
Posts: 79
Joined: Wed Aug 17, 2011 12:56 pm
No, there are many factors that influence the time/speed, but all being equal: There should be a surtain grade were the are the same. I just dont know what that grade is.

xcforme
Posts: 38
Joined: Fri Sep 18, 2009 5:17 pm
http://www.training4cyclists.com/how-much-time-does-extra-weight-cost-on-alpe-dhuez/

Here's a fun little experiment showing how much weight and rolling resistance will affect performance.

Apparently, on Alpe d'Huez, 1,8 kg of extra weight equals 1.54 min time difference.
More interestingly; riding it with a tire pressure of only 3 bars is just 1 min slower.

Very steep: Time depends almost entirely on relative power (W/kg)

Geoff
Posts: 5120
Joined: Sat Dec 13, 2003 2:25 am