*Tour Aero Bike Test 2019*

Discuss light weight issues concerning road bikes & parts.
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LeDuke
Posts: 1482
Joined: Sun Oct 07, 2012 2:39 am
Location: Front Range, CO

by LeDuke

Did Kaspar Asgreen win a massive mountain stage at ToC today on a...Venge?

That was kind of amazing.


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by Weenie


TobinHatesYou
Posts: 3315
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

RocketRacing wrote:
Tue May 14, 2019 3:43 am

Bike calculator .com will help visualize the difference. Assuming the same bike/clothes/cda, the larger rider should still have a larger surface area, so more drag. So to go the same speed, the larger rider will need to put out more power. But the difference will not be huge, at least not as much as the power differential.

On the flat, drag and max average power dominate. W/kg is not as relevant, simply because mass has far less influence. This is why sprinters are all heavier, more powerful riders. This is also why w/kg is more important for climbs... and the steeper the climb, the more w/kg becomes key. In a climb, gravity makes itself heard far louder.

There is an interesting article on zwift insider that was just released on pacing the giro stage 1 tt. Basically, half your time is spent on flat, half spend on a near 10% grade. People go faster when they pace under ftp on the flat (saving energy), and over ftp on the climb. So “work hardest when you are slowest.”

Why? Because going faster requires exponentially more work as you hit very quick speeds due to the mathmatical nature of drag. So for a 10% increase in power, you might only see a 5% increase in speed on the flat section.

Increase your power by 10% on the climb, and your speed will increase closer to 9.5%. You can save near a minute by going sub ftp on the flats, and over ftp on the climb vs a steady even ftp the entire stage.

But... the slower you are, the more seconds you save with an aero bike.... mainly because you are on the track longer. But you still loose.

This is your periodic reminder than a larger rider's surface area increases as a square, but his muscle volume/power increases as a cube. This why the best TTers are often 6' or taller.

Also yes, pacing a TT is a science. At a recent TT, one of my teammates had an out leg of 35mph at 270W and the return was 21mph at 300W.
Last edited by TobinHatesYou on Tue May 14, 2019 5:08 am, edited 2 times in total.

cajer
Posts: 181
Joined: Sun Jul 14, 2013 1:26 am

by cajer

Calnago wrote:
Tue May 14, 2019 1:49 am
@cajer: I’ve ridden the rim brake Madone. And if you’ve been around here for any kind of time at all you likely know I’m not the world’s biggest fan of disc brakes on high end road race bikes. However, I do insist on good braking, regardless of whether it’s rim or disc and have to say I felt the Madone’s brakes are not up to a standard I can appreciate any more than a “meh, they work, sorta” kinda way. As such I’d say go disc brake if you go with the Madone.
Thanks allot for the detailed response. Do you happen to remember which wheels you were riding them with? As if it was with carbon wheels that had a bad braking surface, I might be able to live with it/maybe better wheels would improve it. However if it’s aluminum or good braking carbon wheels I’ll go disc.

cajer
Posts: 181
Joined: Sun Jul 14, 2013 1:26 am

by cajer

Calnago wrote:
Tue May 14, 2019 1:49 am
@cajer: I’ve ridden the rim brake Madone. And if you’ve been around here for any kind of time at all you likely know I’m not the world’s biggest fan of disc brakes on high end road race bikes. However, I do insist on good braking, regardless of whether it’s rim or disc and have to say I felt the Madone’s brakes are not up to a standard I can appreciate any more than a “meh, they work, sorta” kinda way. As such I’d say go disc brake if you go with the Madone.

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Calnago
Posts: 7957
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

^ ENVE 6.7’s, Aeolus 5, Lightweights.
Brakes are a pain in the ass to adjust and keep adjusted. Open industrial type design just is a magnet for grit and dirt to collect in every corner. Performance was sub par. The newest version of the Madone has redesigned the placement a bit (behind the fork etc) and they’ve done away with the trap door “wings”, but the brakes themselves are still essentially the same.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

robertbb
Posts: 863
Joined: Thu Jul 23, 2009 3:35 am
Location: Melbourne, Australia

by robertbb

cajer wrote:
Tue May 14, 2019 4:36 am
Calnago wrote:
Tue May 14, 2019 1:49 am
@cajer: I’ve ridden the rim brake Madone. And if you’ve been around here for any kind of time at all you likely know I’m not the world’s biggest fan of disc brakes on high end road race bikes. However, I do insist on good braking, regardless of whether it’s rim or disc and have to say I felt the Madone’s brakes are not up to a standard I can appreciate any more than a “meh, they work, sorta” kinda way. As such I’d say go disc brake if you go with the Madone.
Thanks allot for the detailed response. Do you happen to remember which wheels you were riding them with? As if it was with carbon wheels that had a bad braking surface, I might be able to live with it/maybe better wheels would improve it. However if it’s aluminum or good braking carbon wheels I’ll go disc.
Why not ride both and decide for yourself, rather than relying on someone elses experience?

TobinHatesYou
Posts: 3315
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

The placement of the brakes on the back of the new rim brake Madone's fork is probably even worse than the last iteration in terms of dirt accumulation. There's no areas dirtier on my bikes than the fork behind the crown and the back of my seat tube.

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Noctiluxx
Posts: 679
Joined: Tue Feb 07, 2017 7:17 pm
Location: Southern California

by Noctiluxx

cajer wrote:
Tue May 14, 2019 4:36 am
Calnago wrote:
Tue May 14, 2019 1:49 am
@cajer: I’ve ridden the rim brake Madone. And if you’ve been around here for any kind of time at all you likely know I’m not the world’s biggest fan of disc brakes on high end road race bikes. However, I do insist on good braking, regardless of whether it’s rim or disc and have to say I felt the Madone’s brakes are not up to a standard I can appreciate any more than a “meh, they work, sorta” kinda way. As such I’d say go disc brake if you go with the Madone.
Thanks allot for the detailed response. Do you happen to remember which wheels you were riding them with? As if it was with carbon wheels that had a bad braking surface, I might be able to live with it/maybe better wheels would improve it. However if it’s aluminum or good braking carbon wheels I’ll go disc.
Colnago needs to mention the rim brake Madone he rode is the previous generation. I own the new 2019 SLR (rim brake) and have ridden the previous vesrion (2018) with Zipp 404 NSW's close to 1000 miles. The current rim brake version with Bontrager XXX 6 wheels has vastly superior braking to previous generation. The brake caliper placement has been moved and provides far better torque than the 2018 model. I have four rim brake road bikes with the Madone having the best braking, overall.
2018 Bianchi Oltre XR4, (Celeste Matt)
2018 De Rosa SK Pininfarina (Blu)
2019 Trek Madone SLR (Rage Red)
2019 Giant TCR Advanced SL (Chameleon Blue)
2019 Giant Revolt Advanced 0

robeambro
Posts: 465
Joined: Sat Jul 07, 2018 6:21 pm

by robeambro

I feel ignored, maybe all of those calculations were not interesting. But hey at least nobody openly disagreed :mrgreen:

ichobi
Posts: 876
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

LeDuke wrote:Did Kaspar Asgreen win a massive mountain stage at ToC today on a...Venge?
That was kind of amazing.
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On a venge, and in speed suit.

Image

Quickstep is one of the few teams who is all-in in the aero game. They wear onesie for most of the races... classics, gts, stage races, you name it. Their aces always wear speedsuit. And now they wear it on a mountain stage.
Last edited by ichobi on Tue May 14, 2019 2:48 pm, edited 1 time in total.

Stueys
Posts: 286
Joined: Sat Nov 22, 2014 1:12 pm

by Stueys

A venge is very close to the weight limit, aero makes you faster (especially if you're hitting climbs at a sustained 400+w), so no real downside to the pro's using a venge on a lumpy stage.

RocketRacing
Posts: 612
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

The specialist mountain bike pros wear speeds suits also. I would to if i were pro.

And good point on the uci weight limit, as it really limits the weight loss a climbing bike can have. Makes aero even more appealing.

Vermu
Posts: 297
Joined: Wed Dec 22, 2010 6:39 am

by Vermu

As almost all aero bikes could hit the UCI limit I think aero is no brainer.

For WWs it’s not...


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ichobi
Posts: 876
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

Vermu wrote:
Tue May 14, 2019 1:50 pm
As almost all aero bikes could hit the UCI limit I think aero is no brainer.
For WWs it’s not...
lol so much this.

by Weenie


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cyclespeed
Posts: 616
Joined: Mon Jun 06, 2016 8:45 am

by cyclespeed

In the real world, I would definitely query the '6%' figure for swapping aero for climbing bike.

6% is a decent hill and most amateur riders will be at around 15kmh, a speed too low for aero to have any significant effect. Climbing feel and efficiency are far more important here.

Even a 4% hill will see most below 20kmh which is still not fast enough for aero to kick in IMO.

(I'm talking about climbs of at least 5kms).

I have been on Tarmacs for many years and currently have an Sworks SL6. I climb quite a bit. No way would I swap my Tarmac for a Venge or S5 on a 6% climb.

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