RoadBikeReview.com's Forum Archives - General


Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )


Calculating Watts???(4 posts)

Calculating Watts???Aztecs
Nov 4, 2002 8:02 AM
One of the test in the Cyclist's Training Bible is to determine MAX/AVG watts (over a 0.2 mile course on a Computrainer). I do not have access to a Computrainer but would like to get a rough estimate for AVG/MAX watts. Is there a formula that uses MPH. I have a Cycleops + Cateye Astrale computer. Could I just go all out for 25-40 seconds (which would be about 0.2 miles) and use my MAX/AVG speed? From here can I get MAX/AVG watts? Do any other factors come into play?

Thanks
Sorry for the multiple posts. Not sure how that happened (nm)Aztecs
Nov 4, 2002 8:05 AM
So many factors come into playPODIUMBOUNDdotCA
Nov 4, 2002 1:51 PM
Watts are based on speed of the wheel times workload. Your speed you know but its impossible to accurately determine your workload based on your gear, friction, drag and grade. Even a computrainer compared to a wingate bike isn't all that great due to tire slippage, frame flex, etc.. But if you were to do a test I'd recommend finding either a 0.2 mile circuit either outside or on rollers and go all out for 30 secs (recording distance). Then from this use your max and avg speed and carefully record the gear for future reference when you redo the test.

Cheers,
Nick
PodiumBound.ca
Some rough numbersKerry
Nov 4, 2002 5:27 PM
A 150 lb/68 kg rider, flat roads, 20 mph/32.2 kph = 170 watts. 180 lb/82 kg rider, 175 watts. 24 mph/38.6 kph = 270 watts for the lighter rider, 277 for the heavier. YMMV.