tour mag aero test 2018

Discuss light weight issues concerning road bikes & parts.
L3X
Posts: 284
Joined: Wed Feb 25, 2009 8:39 pm

by L3X

Just messing around with their data, there surely are some interesting things to highlight:
-When trying to predict the total times for flat/hills/mountains based on CWA, there's a very strong positive correlation between the two. Aero matters less when including more climbing meters into the simulation

-When trying to predict the total times for flat/hills/mountains based on weight, there's a quite a strong negative correlation for both the flat & hills data, and no reasonable correlation for the mountain data. Interestingly the correlation in all cases is negative, i.e. added weight reduces the overall time in all 3 scenarios

wingguy
Posts: 3739
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

spartan wrote:
Tue Jan 30, 2018 5:03 am
the aero data graph is quite revealing. the super exotic zipp 454 nsw is less aero than the 404 fc. :lol:
Something strange going on there. In the simulation results the Aeroad is clearly shown as faster on all 3 courses with the 454NSW than 404FC, even though the FC is shown as lower drag and the calculated effect of the 165g weight penalty should be miniscule on the flat and rolling profile...?

by Weenie


spartan
Posts: 1106
Joined: Fri Sep 03, 2004 2:52 am

by spartan

yes i also noticed this discrepancy. could it be weight? the stock 404 are quite heavy ~1650gm
Current Rides:

2017 Giant TCR Advanced SL 0 DI2 9150

Marin
Posts: 2692
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

On the Tour forum some people are suspecting there are errors in the tables (data swaps).

Shrike
Posts: 1155
Joined: Fri Jun 03, 2016 5:08 pm

by Shrike

Thanks Marin, didn't know Tour had a forum. Makes for interesting reading, lots of solid questions posed.

The translation is good enough to read clearly:

https://translate.google.co.uk/translat ... rev=search

Marin
Posts: 2692
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

Here's the actual thread (that I happened to start): http://forum.tour-magazin.de/showthread ... ests/page5

Bordcla
Posts: 129
Joined: Wed Dec 20, 2017 3:42 pm

by Bordcla

So, on the slowest bike (Giant TCR), one saves a minute on every parcours by keeping the stock 30 mm wheels vs switching to the pricey 404 FC. Aerodynamically speaking, how does that make any sense?

Greatest difference between fast bike and slowest bike is about 4 minutes on about 3 hours +. Which is to say, in a long triathlon, ride a tri bike with deep wheels. In a fast time trial, ride the best bike you can buy, disc wheel. For everything else, the difference isn't that great at all... Ride what you like and enjoy it!

bllx
Posts: 21
Joined: Sat Aug 02, 2014 1:54 pm

by bllx

Was the same model of tire used for all test, or were stock wheels tested with stock tires?

wingguy
Posts: 3739
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

Bordcla wrote:
Fri Feb 02, 2018 2:51 pm
So, on the slowest bike (Giant TCR), one saves a minute on every parcours by keeping the stock 30 mm wheels vs switching to the pricey 404 FC. Aerodynamically speaking, how does that make any sense?
Very odd, especially since the Propel with deep section stock wheels is the other way around.

Either some of the data rows have been switched around or the simulation gives waaaay too much bias towards wheel weight...

User avatar
Beaver
Posts: 341
Joined: Wed Aug 18, 2004 6:06 pm
Location: Lower Saxony - Germany

by Beaver

There are definitely mistakes in the list, not only that the Giant TCR is faster with 30mm stock wheels instead of the 404...

Image

Source: https://translate.google.com/translate? ... 45739.html

Maybe they will publish a corrected one later.

thumper88
Posts: 146
Joined: Tue Mar 13, 2012 7:27 pm

by thumper88

cunn1n9 wrote:
Wed Jan 31, 2018 8:05 am
Everytime they run these tests the data seems to change slightly. They did a test a while back on the F10 and found it was as fast as the Madone. Now there is a different result. There is not a big difference which tells me that the margin of error in the wind tunnel is probably around 10W and that all the bikes in the top tier - Madone, F8/10, S5, etc are so close it doesn't matter.

Thoughts?

Whatever the variations in test methodology, they were probably close to the end of the scale that was optimal for the F10 in that particular test earlier that got a lot of Pinarello fanboys excited.
It's just not in the same ballpark as true aerobikes. More of an all-arounder with some nods to aero like SL6 or R5. Super competent bike but not an aerobike.

Hexsense
Posts: 368
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

RyanH wrote:
Wed Jan 31, 2018 6:21 am
It puts things into perspective a bit better to understand that we're comparing 411w for one frame vs 406w for another. Not nearly as significant.
So just few watts from Giant TCR against Trek Madone?
Well, that almost make me want to just select a frame based on ride quality rather than aero quantity then.


PS. seems like they fixed their data.

happyon2wheels
Posts: 38
Joined: Wed Jan 31, 2018 8:17 am
Location: Denmark

by happyon2wheels

Bordcla wrote:
Fri Feb 02, 2018 2:51 pm
For everything else, the difference isn't that great at all... Ride what you like and enjoy it!
This :thumbup:

guyc
Posts: 375
Joined: Thu Mar 24, 2011 9:40 am
Location: Hampshire, England
Contact:

by guyc

Hexsense wrote:
Thu May 03, 2018 6:39 am

Well, that almost make me want to just select a frame based on ride quality rather than aero quantity then.
That should always be your approach unless you ride for a living anyway.

bm0p700f
in the industry
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Location: Glermsford, Suffolk U.K
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by bm0p700f

When doing 25mph I have to put out alot more than 200w. The differences are not that great between bikes

It is also interesting that the zipps do not drop the CDA for all bikes. For the first few CDA rises with the zipps. I presume that means the stick wheels are more aero in these cases unless there is some odd interplay between wheels and frame.

by Weenie


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