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Ft per hour challenge

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atlas_shrugged View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote atlas_shrugged Quote  Post ReplyReply Direct Link To This Post Posted: 27 May 2020 at 4:53pm
Hmmm. Using your figures gives 183.6 W with the below formula.

=$A$2*233*9.81/(2.205*3600*3.281)

Are you loosing some power somewhere on the bike? Sorry for being Nerdy I am just interested in the figures.
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russellbridge View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote russellbridge Quote  Post ReplyReply Direct Link To This Post Posted: 27 May 2020 at 5:09pm
Rider + all-up bike/clothing/fluid weights are: 
Mike 96kg 185cm
Russ 89kg 177cm
Gautier 92Kg 185cm

First three all on decent upright road bikes with low rolling resistance tyres.

Not sure if aero comes into it much at the lower climbing speeds, although Mike was using a dip and accelerating down one side to get him some of the way up the other...so his average speed was 17mph where as everyone else was circa 11mph.

There was also a 15mph tailwind blowing me up Snake Pass, which made the downhill slow and very sketchy, needing the whole lane. That's obviously going to throw the power figures out too, but no idea how!
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farwer View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farwer Quote  Post ReplyReply Direct Link To This Post Posted: 27 May 2020 at 7:00pm

Not sure whether I am losing power somewhere. What number does it give you for Russel? What’s the value in $A$2?

Russel did the west ascent 2 and a bit times. I did the east ascent, then down to Glossop which was all against the quite strong wind - then up the west ascend 1 and a bit times. 

Tyres are Schwalbe One front (20'') and Grand Prix 4000 SII rear (Annoyingly, the new and probably better Grand Prix 5000 seems to be available in 584 instead of the needed 571.

Of course the power meter could be off but I had it serviced a few times and numbers seem consistent over the years.



Edited by farwer - 27 May 2020 at 7:07pm
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atlas_shrugged View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote atlas_shrugged Quote  Post ReplyReply Direct Link To This Post Posted: 27 May 2020 at 7:30pm
Using more accurate bike and rider weights:
 
Mike 3114ft 96kg 248.3 W
Russ 2487ft 89kg 183.8 W
Gautier 2201ft 92kg 168.2 W
 
Spreadsheet (mgh/time) formula used where $A$1 is kg and $B$1 is ft (note: E&OE)

=$A$1*$B$1*9.81/(3600*3.281)

@farwer I would trust your power meter but would expect more ft similar to Russell but I guess a swap of the bike and the route is needed to explain the difference.
 
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farwer View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farwer Quote  Post ReplyReply Direct Link To This Post Posted: 27 May 2020 at 9:50pm
Yes. Looking at mine and Russel's power data and weights I am quite sure on same bikes and same route it would be pretty similar but Russel still in front.
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