Go Back  Bike Forums > Bike Forums > Triathlon
Reload this Page >

What's more important - aero wheel up front or rear?

Triathlon Swim / Bike / Run your thing? Drop in our new triathlon forum for the latest in training & gear. From beginner to expert, and sprint to ironman.

What's more important - aero wheel up front or rear?

Reply

Old 09-26-07, 07:34 PM
  #1  
arcadiantri
Junior Member
Thread Starter
 
Join Date: Sep 2007
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
What's more important - aero wheel up front or rear?

I already know the importance of aerodynamics, how an aero wheel can save you on the time and energy spent. But if I were to use just one aero wheel, where would it be more beneficial? In the front or the rear? Utilizing two aero wheels are not an option. I'm curious to hear everyone's opinion on this one. All other factors held constant (will not discuss the whole weight issue associated). Thanks!
arcadiantri is offline  
Reply With Quote
Old 09-26-07, 08:35 PM
  #2  
Dalai
Senior Member
 
Join Date: Jan 2006
Location: Australia
Posts: 2,133
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Aero front wheel is more important over an aero rear wheel offering the greatest benefit of the two as it is hitting 'clean' air.

An old study but shows some interesting details. http://www.damonrinard.com/aero/aerodynamics.htm

Most important of all is for the rider to be in an optimal position which is comfortable enough to hold the whole race. There is no point having an aggressive position you can't hold for more than a few minutes...
Dalai is offline  
Reply With Quote
Old 09-26-07, 09:38 PM
  #3  
arcadiantri
Junior Member
Thread Starter
 
Join Date: Sep 2007
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
That's a very interesting study. In the comparison study of a front disk vs a rear disk, you save 2x more time with a front aero disk wheel over a 40km distance.
Another figure that jumped out for me was the time saved with the removal of the water bottle and its cage.
arcadiantri is offline  
Reply With Quote
Old 09-26-07, 10:43 PM
  #4  
Dalai
Senior Member
 
Join Date: Jan 2006
Location: Australia
Posts: 2,133
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Though without hydration for 40 km drop in performance will counteract the gains.

Another view on the bottle on the seat tube / down tube aerodynamics...

http://www.slowtwitch.com/mainheadin...erbottles.html
Dalai is offline  
Reply With Quote
Old 09-27-07, 12:20 PM
  #5  
bvfrompc
Senior Member
 
bvfrompc's Avatar
 
Join Date: Sep 2005
Posts: 1,277
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Whats a Shultang? And where can I get an inexpensive one?
bvfrompc is offline  
Reply With Quote
Old 09-27-07, 05:35 PM
  #6  
Flak
Flatland hack
 
Flak's Avatar
 
Join Date: Nov 2005
Location: Nowhere near the mountains :/
Posts: 3,228
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Get an aero helmet instead.
__________________
My shop - www.spinbikeshop.com
My team - www.teampanther.com
Flak is offline  
Reply With Quote
Old 09-27-07, 06:37 PM
  #7  
asgelle
Senior Member
 
Join Date: Apr 2006
Location: Albuquerque, NM
Posts: 3,633
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 336 Post(s)
Originally Posted by Flak View Post
Get an aero helmet instead.
Only if the objective is to save money rather than go fast.
asgelle is offline  
Reply With Quote
Old 09-28-07, 02:34 AM
  #8  
Treefox
Young and unconcerned
 
Treefox's Avatar
 
Join Date: Apr 2006
Location: Merry Land
Posts: 4,123

Bikes: Yeah, I got a few.

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Don't put a disk on the front - it'll seriously affect your handling.
Treefox is offline  
Reply With Quote
Old 09-28-07, 02:47 AM
  #9  
gcl8a
Je pose, donc je suis.
 
gcl8a's Avatar
 
Join Date: Mar 2006
Location: Odense, Denmark
Posts: 1,463
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by Dalai View Post
An old study but shows some interesting details. http://www.damonrinard.com/aero/aerodynamics.htm
Is pcad watching?

Smooth nylon socks: $8 0,4% 4 sec
gcl8a is offline  
Reply With Quote
Old 09-28-07, 03:09 AM
  #10  
Treefox
Young and unconcerned
 
Treefox's Avatar
 
Join Date: Apr 2006
Location: Merry Land
Posts: 4,123

Bikes: Yeah, I got a few.

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by gcl8a View Post
Is pcad watching?

Smooth nylon socks: $8 0,4% 4 sec
That's 8 Deutchmarks, I think.


Who even sells a front disk anymore?
Treefox is offline  
Reply With Quote
Old 09-28-07, 07:50 AM
  #11  
Flak
Flatland hack
 
Flak's Avatar
 
Join Date: Nov 2005
Location: Nowhere near the mountains :/
Posts: 3,228
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by asgelle View Post
Only if the objective is to save money rather than go fast.
I assumed that since he only wants one aero wheel it was because of financial constraints.

That said though, i read an article a little while ago that basically concluded that an aero helmet has a benefit on par with a set of zipp 404s
__________________
My shop - www.spinbikeshop.com
My team - www.teampanther.com
Flak is offline  
Reply With Quote
Old 09-28-07, 10:01 AM
  #12  
asgelle
Senior Member
 
Join Date: Apr 2006
Location: Albuquerque, NM
Posts: 3,633
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 336 Post(s)
Originally Posted by Flak View Post
I assumed that since he only wants one aero wheel it was because of financial constraints.

That said though, i read an article a little while ago that basically concluded that an aero helmet has a benefit on par with a set of zipp 404s
That data was flawed and the conclusion incorrect. Search MIT hlemet aero wheel.
asgelle is offline  
Reply With Quote
Old 09-28-07, 10:28 AM
  #13  
ranger5oh
Just shy of 400W
 
ranger5oh's Avatar
 
Join Date: Apr 2006
Location: Saint Louis
Posts: 765

Bikes: Cannondale System 6, Klein Palomino

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Aero helmet does more than a set of aero wheels.

You never run a disc on front, and in fact they arent allowed.

If you have to buy an aero wheel, buy a rear disc.
__________________
2008 Cannondale System Six
2003 Klein Palomino MTB

60% of the time, it works everytime.
ranger5oh is offline  
Reply With Quote
Old 09-28-07, 10:34 AM
  #14  
asgelle
Senior Member
 
Join Date: Apr 2006
Location: Albuquerque, NM
Posts: 3,633
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 336 Post(s)
Originally Posted by ranger5oh View Post
Aero helmet does more than a set of aero wheels.
Repeating it doesn't make it true. The only data showing this (MIT) was shown to be erroneous.

Originally Posted by ranger5oh View Post
You never run a disc on front, and in fact they arent allowed.
Aren't allowed by whom? They're certainly legal for USCF racing, and there are enough pictures on cyclingnews with them to make me believe they're legal for UCI.
asgelle is offline  
Reply With Quote
Old 09-28-07, 10:44 AM
  #15  
Treefox
Young and unconcerned
 
Treefox's Avatar
 
Join Date: Apr 2006
Location: Merry Land
Posts: 4,123

Bikes: Yeah, I got a few.

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
An aero helmet is waaaay cheaper than a Zipp 404.
Treefox is offline  
Reply With Quote
Old 09-28-07, 10:46 AM
  #16  
ranger5oh
Just shy of 400W
 
ranger5oh's Avatar
 
Join Date: Apr 2006
Location: Saint Louis
Posts: 765

Bikes: Cannondale System 6, Klein Palomino

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by asgelle View Post
Repeating it doesn't make it true. The only data showing this (MIT) was shown to be erroneous.


Aren't allowed by whom? They're certainly legal for USCF racing, and there are enough pictures on cyclingnews with them to make me believe they're legal for UCI.

It is obvious you arent a triathlete.

As far as the helmet goes, yes, it does make a bigger difference than the wheels. Repeating a fact doesn't make the fact true, but merely publicizes it. So thanks for finding one instance of a study..please talk to some triathletes and see what they say.

USAT governs most races of consequence and here is a quote from their rulebook "(g) Except as otherwise determined by the race director in the interest of safety, the front wheel may be of a
different diameter than the rear wheel, but the front wheel must be of spoke construction. The rear wheel may be either spoke or solid construction. Wheel covers shall only be permitted on the rear wheel."

So no... you can not use a disk on the rear. Next time, please know what you are talking about before you are so quick to criticize.
__________________
2008 Cannondale System Six
2003 Klein Palomino MTB

60% of the time, it works everytime.
ranger5oh is offline  
Reply With Quote
Old 09-28-07, 01:58 PM
  #17  
Flak
Flatland hack
 
Flak's Avatar
 
Join Date: Nov 2005
Location: Nowhere near the mountains :/
Posts: 3,228
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Actually ranger, you can use a disc on the rear under USAT rules, thats the 'solid construction' part. I know you can't use a full disc in WTC races though. Kona springs to mind.

As far as the helmet goes, there's been more than just the MIT study and the conclusions are all similar. They work, on par with a set of aero wheels.
__________________
My shop - www.spinbikeshop.com
My team - www.teampanther.com
Flak is offline  
Reply With Quote
Old 09-28-07, 07:33 PM
  #18  
asgelle
Senior Member
 
Join Date: Apr 2006
Location: Albuquerque, NM
Posts: 3,633
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 336 Post(s)
Originally Posted by Flak View Post
As far as the helmet goes, there's been more than just the MIT study and the conclusions are all similar. They work, on par with a set of aero wheels.
I've seen plenty of data on wheels and helmets showing this is not so, but no data showing it is. With the only exception being those studies which considered only the unrealistic 0 yaw condition. Do you have a reference for a study showing data where aero helmets reduce drag more than a set of aero wheels over a range of yaw angles or even one realistic value?
asgelle is offline  
Reply With Quote
Old 09-29-07, 11:37 AM
  #19  
Flak
Flatland hack
 
Flak's Avatar
 
Join Date: Nov 2005
Location: Nowhere near the mountains :/
Posts: 3,228
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
No i don't. I'm not into the whole keyboard warrior thing where i feel i need to cite to win an e-argument.

I'm just regurgitating what i read. Take it or leave it - doesn't matter to me.
__________________
My shop - www.spinbikeshop.com
My team - www.teampanther.com
Flak is offline  
Reply With Quote
Old 09-29-07, 04:14 PM
  #20  
asgelle
Senior Member
 
Join Date: Apr 2006
Location: Albuquerque, NM
Posts: 3,633
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 336 Post(s)
Originally Posted by Flak View Post
No i don't. I'm not into the whole keyboard warrior thing ...
What I'm asking for is an end to that keyboard warrior thing you refer to. I'm not asking anyone to take my word for anything. There are discussions on slowtwitch regarding the change in drag with yaw angle for wheels and helmets. There is plenty of data on wheels and helmets at 0 yaw (from which the relative benefit at non-zero yaw can be inferred from the slowtwitch discussions. Though that isn't necessary as there is plenty of data for both at non-zero yaw out on the web. Anyone can take a look at the data and the results are clear.

On the other hand, we have you citing unnamed articles (not actual data) and not even a direct reference, but now we're supposed to take your regurgitation of facts at face value.

I think people can make up their own minds.
asgelle is offline  
Reply With Quote
Old 09-29-07, 06:05 PM
  #21  
bvfrompc
Senior Member
 
bvfrompc's Avatar
 
Join Date: Sep 2005
Posts: 1,277
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by bvfrompc View Post
Whats a Shultang? And where can I get an inexpensive one?
Great, noone else knows what this yet it could be saving us time accroding to that old study
bvfrompc is offline  
Reply With Quote
Old 09-29-07, 09:09 PM
  #22  
Flak
Flatland hack
 
Flak's Avatar
 
Join Date: Nov 2005
Location: Nowhere near the mountains :/
Posts: 3,228
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by asgelle View Post
On the other hand, we have you citing unnamed articles (not actual data) and not even a direct reference, but now we're supposed to take your regurgitation of facts at face value.
You don't have to take anything i say as anything at all if you don't want. I'm just telling you what I've read in random articles online and in magazines, which is that helmets are just as good, or damn close to a 404 wheelset (no solids).

I'm neutral on the subject. I don't have aero anything
__________________
My shop - www.spinbikeshop.com
My team - www.teampanther.com
Flak is offline  
Reply With Quote
Old 09-30-07, 01:32 AM
  #23  
Dalai
Senior Member
 
Join Date: Jan 2006
Location: Australia
Posts: 2,133
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Cmon guys, play nice!

Just to clarify a few points -

bvfrompc - Shultang directly translates to 'circuit' via babel fish translation from German. All I can gather is Shimano Sante (groupset back in the day) had either aero levers or brakes, though I have a set in the shed of both and don't appear more aero than usual unless they had another version.

ranger5oh -Front aero wheel has a greater time gain than the rear in every study I have seen, even if the rear wheel is a disk - as the front wheel faces clean air. The Aero helmet is definitely a worthy tool and valuable in the arsenal of go fast kit especially for the price but not as beneficial as wheels.

Disk on the front. Not legal for road as far as I am, aware and the uci rules (though I did recently see some pics from the Italian TT championships where a rider did have a front disk!?) or tri's (rules explained above by ranger5oh).

Aero Helmet better than aero wheels - Brief article was published in bicycling magazine with a comment about the value of aero helmets vs wheels from a guy from M.I.T.S. As asgelle has already said (though in a 'tone' which usual causes tension) the comment was based on 0 degrees yaw which isn't a realistic test given wind directions fluctuate considerably. So as soon as the wind starts to angle the aero benefits of the wheels improves considerably over the lid.

Last edited by Dalai; 09-30-07 at 05:35 PM.
Dalai is offline  
Reply With Quote
Old 02-22-18, 09:16 PM
  #24  
jadesnakebiker
Bike God
 
jadesnakebiker's Avatar
 
Join Date: Nov 2017
Location: Atlanta
Posts: 23

Bikes: 1987 Schwinn Prelude

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Originally Posted by arcadiantri View Post
That's a very interesting study. In the comparison study of a front disk vs a rear disk, you save 2x more time with a front aero disk wheel over a 40km distance.
Another figure that jumped out for me was the time saved with the removal of the water bottle and its cage.
funny enough they actually have bikes these days with integrated bottle cages on the downtube that actually make the bike faster with than without. the cage basically just serves to extend the aeroblade
jadesnakebiker is offline  
Reply With Quote
Old 02-22-18, 09:21 PM
  #25  
jadesnakebiker
Bike God
 
jadesnakebiker's Avatar
 
Join Date: Nov 2017
Location: Atlanta
Posts: 23

Bikes: 1987 Schwinn Prelude

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
@Treefox you bring up the point I was going to make which is that you most often see TT athletes using a disc in the back and a trispoke or other slightly less aggressive wheel in the front.

This is because sidewinds hitting a front disc wheel can cause dramatic destabilization of the steering and make you crash. But as others have noted, if you want to take the risk and aren't limited by race rules, a front disc is more effective than a rear.
jadesnakebiker is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service