Weight weenies vs watt weenies...

Discuss light weight issues concerning road bikes & parts.

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V3Rs
Posts: 69
Joined: Sun Jul 31, 2022 10:54 pm

by V3Rs

I was wondering about the general evolution of aerodynamics on frame and component design.

My question is that if one could start with a great frame from the pre wattage era, say a C-40,
and measure its aerodynamic effeciency with a rider wearing clothing from that era and compare
it to say a Cervelo S-5 with a rider wearing the best clothing of this era, what would we find?

I dont even know how this is measured but at the end of the day, wouldrotating ones head downward
a few degrees be more or less than these "improvements?"

TobinHatesYou
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Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

V3Rs wrote:
Tue Aug 09, 2022 11:47 pm
I was wondering about the general evolution of aerodynamics on frame and component design.

My question is that if one could start with a great frame from the pre wattage era, say a C-40,
and measure its aerodynamic effeciency with a rider wearing clothing from that era and compare
it to say a Cervelo S-5 with a rider wearing the best clothing of this era, what would we find?

I dont even know how this is measured but at the end of the day, wouldrotating ones head downward
a few degrees be more or less than these "improvements?"
Helmets don’t want to be rotated downward. The ideal position is an awkward kinking of the neck and shoulder shrug with the helmet at more of a 40deg angle. Ideally there would be minimal gap between the back of the helmet and your upper back.
Last edited by TobinHatesYou on Wed Aug 10, 2022 12:25 am, edited 2 times in total.

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V3Rs
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by V3Rs

Helmets don’t want to be rotated downward. The ideal position is an awkward kinking of the neck and should shrug with the helmet at more of a 40psi angle. Ideally there would be minimal gap between the back of the helmet and your upper back.
[/quote]

Useless answer...

TobinHatesYou
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by TobinHatesYou

V3Rs wrote:
Wed Aug 10, 2022 12:21 am

Useless answer...

Just pointing out that your intuition fails you. Anyway aero tube shapes vs round tube shapes might add up to 20-25W in a near worst case at 45km/h. Getting your body roughly 2cm lower is also about a 20W difference at 45km/h. The best skinsuits save >10W over regular modern bibs/jersey at 45km/h.
Last edited by TobinHatesYou on Wed Aug 10, 2022 6:06 pm, edited 1 time in total.

bananastand
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Joined: Thu Aug 02, 2012 7:45 am

by bananastand

V3Rs wrote:
Wed Aug 10, 2022 12:21 am
Helmets don’t want to be rotated downward. The ideal position is an awkward kinking of the neck and should shrug with the helmet at more of a 40psi angle. Ideally there would be minimal gap between the back of the helmet and your upper back.
Useless answer...
[/quote]

Wow you're fun.

At 45kmh I'm guessing it's about 80-100 watts (clothes, wheels, helmet, frame)

TobinHatesYou
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by TobinHatesYou

bananastand wrote:
Wed Aug 10, 2022 12:33 am

Wow you're fun.

At 45kmh I'm guessing it's about 80-100 watts (clothes, wheels, helmet, frame)

Admittedly the average speed of a large peloton only depends on the first 15 or so riders while everyone else gets sucked a long, so aggregate speeds haven't changed as much. Breaks and sprints are where modern bikes shine.

spartacus
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Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

There's no way in hell it's 80-100w at 45kph. Average race speeds weren't that much slower back then and there are still some competitive course records from back in the day.

TobinHatesYou
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by TobinHatesYou

spartacus wrote:
Wed Aug 10, 2022 12:49 am
There's no way in hell it's 80-100w at 45kph. Average race speeds weren't that much slower back then and there are still some competitive course records from back in the day.

See my previous reply.

V3Rs
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by V3Rs

This is theoretical question- wind tunnel stuff maybe ITT- not peloton....
Yes, I am fun when something is funny......

spartacus
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by spartacus

TobinHatesYou wrote:
Wed Aug 10, 2022 1:03 am
spartacus wrote:
Wed Aug 10, 2022 12:49 am
There's no way in hell it's 80-100w at 45kph. Average race speeds weren't that much slower back then and there are still some competitive course records from back in the day.

See my previous reply.
So the first 15 riders are immune to the aero advantage because.... ?

maxim809
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by maxim809


maxim809
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by maxim809

btw I think TBY's point is that in a field with +100 ppl, the guys rotating on the front would naturally just take shorter pulls if they have to do an extra 80~100w extra at pro peloton speeds

it's NOT that they are not immune

it's also NOT like every cyclist, whether pro or not, actively "measures" a 80~100w difference and 'titrates' their turns based off of that

if you deplete anaerobically faster because you're less aero, you simply flick sooner in hopes of keeping the speed high

that's why the importance of aero matters MORE in a sprint or break, but in a peloton it's less pronounced because you have the field to lean on

if you race, you know

spartacus
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by spartacus

I don't agree with "they're just going to take shorter pulls". If the difference was really 100w the speeds would be faster full stop. 20 watts otoh I believe and that's what I would guess based on my personal experience.

Also it's not like 10-20 years ago everyone just wore a flappy kit it was still possible to get tight fitting kit.

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ArtifactsInMotion
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by ArtifactsInMotion

spartacus wrote:
Wed Aug 10, 2022 2:17 am
I don't agree with "they're just going to take shorter pulls". If the difference was really 100w the speeds would be faster full stop. 20 watts otoh I believe and that's what I would guess based on my personal experience.

Also it's not like 10-20 years ago everyone just wore a flappy kit it was still possible to get tight fitting kit.
The speeds have been trending faster since a decade ago. This is largely attributed to more emphasis on rider fitness,aero, and weight. Here's some supporting material https://cyclingtips.com/2022/06/why-has ... stigation/
'22 Orbea Orca Aero: 57cm DA92, Bontrager RSL62, ENVE 27mm, 7.9kg
'15 BMC TMR01: 58cm Force AXS 1x, Bora WTO 45, PZero TLRSL 24mm 7.1kg

by Weenie


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spdntrxi
Posts: 4974
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

I have literally 20 watts between my Moots and my Aero BMC.. so if you count clothes I can see 40 pretty easy.

My moots is lighter too.

Dont make me put a powermeter on my Look KG86 :)
2019 BMC TM01R
2002 Moots Compact-SL
2019 Parlee Z0XD
2020 Parlee TTiR

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