Variability index | normalized power | discs for slower riders

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Variability index | normalized power | discs for slower riders | explained in 5mins each

Рет қаралды 3,459

Күн бұрын

We were asked to make this explanation of why Triathlon Taren's disc wheel field test went wrong....it all comes down to variability index and normalized power // plus we explain why disc wheels work best for slower riders.
Taren video: fft.tips/vtaren
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Пікірлер: 20

@SmartBikeTrainers 5 жыл бұрын

Nice video and thanks for explaining VI. That metric isn’t very well understood and how it is used.

@markwaren5048 5 жыл бұрын

Great video. Love the thought and explanation that go into your presentations.

@Fastfitnesstips 5 жыл бұрын

Join us on www.strava.com/clubs/fastfitnesstips; ps. sorry it was not 5mins, actually I did 3x concepts in 15mins: VI + NP + disc wheels!

@christopherYecoYoung 5 жыл бұрын

Loved that video thank you Alex

@ericoschmitt 5 жыл бұрын

Your videos are amazing, thanks!

@Fastfitnesstips 5 жыл бұрын

haha, most people say boring! but thanks for the complement!!

@ericoschmitt 5 жыл бұрын

@@Fastfitnesstips I'm a hopeless geek on all I do! lol So I could only love your videos.

@allthingsTechrelated 5 жыл бұрын

I trust that what you have said is right, my brain is a bit tired at the moment and I’m trying to relax.

@kargs5krun 5 жыл бұрын

Very interesting, math wise, as usual from you, Alex. ✋😉👍 But of course, like life, no two days (3 days, 4 days, etc., lol) "are the same" in re: to conditions, and physiology of the rider. (wind; rain; heat; strength; rest; nutrition; etc.) Thus diff "findings" or math-realities will be the practical results, any particular day/ride/race. Now, _"which side of the bed did i wake up on today.......?"_ 🤔 🚲+🚵‍♂️=🚳

@ericoschmitt 5 жыл бұрын

You only missed % of time saved in the end, which will then be pretty much even for all riders I guess. And that would possibly be the best measure instead of saying "this wheel saves you 10w"

@loopie007 5 жыл бұрын

I agree, he should have been measuring Average Power and not Normalized Power. Also, do lots of runs to get a consistent result, and get away from the cars. They blow you all over and can help or hinder your test. This should be no problem, just run the test again matching AVP instead of NP.

@felipegiachinocastillo2034 5 жыл бұрын

Hi. Great Video! But whats happend with the weight of disc and deep wheel? Because the difference would be shorter when the race has more climbs. Regards!

@Advcrazy 5 жыл бұрын

Any idea what the time difference would be (or power difference required) to ride an aero road bike with zipp 808 +/-disc rear) vs a typical (recent model) tt bike?...assuming aero bars on the road bike and similar position between the two bikes

@thatsnumberwang7432 5 жыл бұрын

Yeah it'd be good to see how fast I could go by putting some aero bars on my road bike compared to spending loads on a TT/triathlon bike

@Fastfitnesstips 5 жыл бұрын

Yes sure James tell me what distance / grade / power and I'll tell you the difference (same wheels)? And weight

@Advcrazy 5 жыл бұрын

@@Fastfitnesstips Hi Alex, the segment is 18.99km, its out and back twice so average gradient is 0%, id expect to average around 350w. i currently have Zipp 808s and a BMC TMR01 and am wondering how far off i'll be by not having a proper TT bike. i think i can get my saddle forward enough to give a similar position. Ive never done the TT as the road race is always in the afternoon and ive always assumed i dont stand a chance on a road bike. but maybe you can convince me otherwise. Here is a link to the strava segment... www.strava.com/segments/20630558?filter=overall Thanks for any help you can offer!!

@ckaldfull 5 жыл бұрын

Did I understand correctly that the conclusion is the following: disc is always aerodynamically better, but Taren messed up his test because of poor handling? Could the disc be the reason for that? It is much more susceptible to crosswinds and passing cars

@Fastfitnesstips 5 жыл бұрын

Handling (ie position on bike) was probably a red herring because he would have noticed this, and deviating from line also a red herring. Conclusion is: discs are always better if you stay in the same aero position (unless there are significant weight penalty with a disc on a steep climb). The reason for the difference in test results was because of the difference in average power due to (most likely) pacing issues on the disc wheel run.

@ckaldfull 5 жыл бұрын

@@Fastfitnesstips Ok, but my claim is that it is more difficult to pace with the disc. So aerodynamical effect != final result