"The 33"-Road Bike Racing - Are the benefits of Aero Wheels negated by wide downtubes?

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spessx
12-06-10, 08:32 AM
Hey guys,

I have an '08 Trek Madone. Anyone familiar with that bike or a lot of the non aero carbon frames on the market know that the downtubes on these bikes are pretty wide - probably 3-4x the width of the front wheel.

So my question is this: Is there any advantage to putting aero wheels on this type of bike? Let me know what you think.

-s


Spring Water
12-06-10, 08:42 AM
No.

Nate552
12-06-10, 08:45 AM
So my question is this: Is there any advantage to putting aero wheels on this type of bike? Let me know what you think.

-s

yes


spessx
12-06-10, 08:45 AM
Very insightful and information filled response!

j/k

Did you mean "No, there's no benefit to putting aero wheels on a madone" or "No, the wide downtube doesn't negate the benefits"?

Spring Water
12-06-10, 08:56 AM
Very insightful and information filled response!
j/k
Did you mean "No, there's no benefit to putting aero wheels on a madone" or "No, the wide downtube doesn't negate the benefits"?

Sorry,

Are the benefits of Aero Wheels negated by wide downtubes?

No.

Is there any advantage to putting aero wheels on this type of bike?

Yes.

johnybutts
12-06-10, 08:58 AM
Very insightful and information filled response!

j/k

Did you mean "No, there's no benefit to putting aero wheels on a madone" or "No, the wide downtube doesn't negate the benefits"?

I think they're joshing with you because of the question.

From the discussions I've had, it seems that aero-ness can never be isolated to single parts. With that said, if you have a steep hill, you can test them out with a coast down (looking for max speed, or maybe time down the hill or something). Keep all other variables the same, do 3-4 trials with your aero wheels, and again with your non-aero wheels.

You'd also want to account for weight differences between the wheels, so possibly filling a water bottle with the weight differential could work. Keep the bottle on th ebike for both runs obviously.

veloboy971
12-07-10, 07:15 AM
Aero wheels will always be faster unless its a 6 or so % grade or higher. Think about it this way too...if the downtube negates the effect of the wheels, you def want those wheels on their to negate some of the downtubes un-aeroness!!!

Racer Ex
12-07-10, 07:21 AM
Aero wheels will always be faster unless its a 6 or so % grade or higher.

Why do aero wheels go slower uphill?

Creakyknees
12-07-10, 08:32 AM
Why do aero wheels go slower uphill?

oh oh oh I love riddles... don't tell me!!!! I'll get it in a minute.

asgelle
12-07-10, 09:27 AM
With that said, if you have a steep hill, you can test them out with a coast down (looking for max speed, or maybe time down the hill or something). Keep all other variables the same, do 3-4 trials with your aero wheels, and again with your non-aero wheels.

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=3107367;search_string=;guest=128971146&t=search_engine#3107367

jfmckenna
12-07-10, 10:20 AM
Aren't aero wheels on the low end of the scale of aero equipment that actually matters? Especially when looking at the cost per aero savings so to speak? And since the far majority of us stay hidden in the pelaton do aero wheels really add up to what they claim in an 80 mile race? TT's on the other hand sure but even there a skin suit and an aero helmet are cheap and offer much more of a benefit.

:popcorn:

Spring Water
12-07-10, 10:24 AM
Aren't aero wheels on the low end of the scale of aero equipment that actually matters? Especially when looking at the cost per aero savings so to speak? And since the far majority of us stay hidden in the pelaton do aero wheels really add up to what they claim in an 80 mile race? TT's on the other hand sure but even there a skin suit and an aero helmet are cheap and offer much more of a benefit.

:popcorn:

A more-aero wheel is always more aero than a less aero wheel.

How many times do we need to have this discussion?

asgelle
12-07-10, 10:37 AM
TT's on the other hand sure but even there a skin suit and an aero helmet are cheap and offer much more of a benefit.

I know helmets offer less benefit than aero wheels under real riding conditions (non-zero yaw) and am pretty sure that's true for skin suits as well. Do you have any data showing the superiority of helmets and skin suits?

Spring Water
12-07-10, 10:49 AM
I know helmets offer less benefit than aero wheels under real riding conditions (non-zero yaw) and am pretty sure that's true for skin suits as well. Do you have any data showing the superiority of helmets and skin suits?

$150 vs $1500 is a place to start.

asgelle
12-07-10, 10:53 AM
$150 vs $1500 is a place to start.

Except you separated out cost and benefit. Here, I'll help you.

TT's on the other hand sure but even there a skin suit and an aero helmet are cheap and offer much more of a benefit.

Spring Water
12-07-10, 10:56 AM
Except you separated out cost and benefit. Here, I'll help you.

Don't be a dick. This discussion has been done plenty. Here, let me help you (http://tinyurl.com/34zuldz).

asgelle
12-07-10, 11:00 AM
Don't be a dick. This discussion has been done plenty. Here, let me help you (http://tinyurl.com/34zuldz).

What are you talking about? You claimed helmets and skin suits performed better that aero wheels and I asked if there was data to support that? If you feel the subject has been beaten to death, why were you the one who raised it? Anyway, I'll take it that your answer is no you don't have any data.

My mistake jfmckenna made the original claim. I don't know if Spring Water misunderstood it or was just confused.

Spring Water
12-07-10, 11:00 AM
What are you talking about? You claimed helmets and skin suits performed better that aero wheels and I asked if there was data to support that? If you feel the subject has been beaten to death, why were you the one who raised it? Anyway, I'll take it that your answer is no you don't have any data.

I'll let you read back through the thread and get your facts straight. Pay attention who's talking, it helps keep things organized.

Racer Ex
12-07-10, 11:06 AM
Do you have any data showing the superiority of...skin suits?

Just these guys:

http://ak.buy.com/PI/0/500/207881366.jpg

http://ecx.images-amazon.com/images/I/31RGwL88bfL.jpg


http://ecx.images-amazon.com/images/I/31D8pRLD-rL._SY445_.jpg

Creatre
12-07-10, 11:14 AM
Just these guys:

http://ak.buy.com/PI/0/500/207881366.jpg

http://ecx.images-amazon.com/images/I/31RGwL88bfL.jpg


http://ecx.images-amazon.com/images/I/31D8pRLD-rL._SY445_.jpg

That's enough proof for me to wear a skinsuit!

jfmckenna
12-07-10, 11:33 AM
A more-aero wheel is always more aero than a less aero wheel.

How many times do we need to have this discussion?

I'd say at least once a week is appropriate.



I know helmets offer less benefit than aero wheels under real riding conditions (non-zero yaw) and am pretty sure that's true for skin suits as well. Do you have any data showing the superiority of helmets and skin suits?

This is an interesting read:
http://www.cyclingtipsblog.com/2010/04/biggest-bang-for-your-buck-in-time-trial-equipment/ and it goes into factoring the whole cost of things which is the point I am trying to make. And of course all these measurment's are on paper and not in real word conditions which like I said most of us are hiding in the pelaton anyway, side winds, echelons, etc...

jfmckenna
12-07-10, 11:34 AM
Just these guys:

http://ak.buy.com/PI/0/500/207881366.jpg

http://ecx.images-amazon.com/images/I/31RGwL88bfL.jpg


http://ecx.images-amazon.com/images/I/31D8pRLD-rL._SY445_.jpg

Hahahhaha :D

DannoXYZ
12-21-10, 03:18 PM
Here's some data for a 40k TT: http://www.ridestrong.org.nz/RS/wikis/getting_started/biggest-bang-for-your-buck-in-time-trial-equipment.aspx

-134s skinsuit
-122s aerobars
-67s aero helmet
-56s body tuck tuning
-42s deep-V front wheel
-30s shoe covers
-29s 3-spoke rear wheel from disc
-23s 5-spoke rear wheel from box-section rim
-17s aero-frame

Nate552
12-21-10, 03:52 PM
Here's some data for a 40k TT: http://www.ridestrong.org.nz/RS/wikis/getting_started/biggest-bang-for-your-buck-in-time-trial-equipment.aspx

-134s skinsuit
-122s aerobars
-67s aero helmet
-56s body tuck tuning
-42s deep-V front wheel
-30s shoe covers
-29s 3-spoke rear wheel from disc
-23s 5-spoke rear wheel from box-section rim
-17s aero-frame

I remember when Velonews printed that awhile back. It's vagueness, but extreme specifics is amusing. 3 to 5 spoke wheel to a deep rim 12 spoke wheel? Well, which was it? A Mavic or a Hed? And what is "deep?" 50? 90? 100? And at 10 degrees? What about 5? And I have seen many TT frames be more than 17 seconds slower that another frame, and I'm talking about a "aero" frame vs an "aero" frame, not round vs aero.

khill
12-21-10, 07:14 PM
My results for our local 10mile TT series...(Over the last year..)

Std road bike-24:41
Std road bike with clip on bars-23:38
TT bike non-aero. (Std wheels, helmet, water bottle in back pocket, etc) 22:36
TT bike full aero-22:15

Racer Ex
12-21-10, 07:40 PM
My results for our local 10mile TT series...(Over the last year..)

Std road bike-24:41
Std road bike with clip on bars-23:38
TT bike non-aero. (Std wheels, helmet, water bottle in back pocket, etc) 22:36
TT bike full aero-22:15

Always keep in mind that times are not necessarily an absolute measure of what's working or not; conditions can often greatly impact performance, and depending on where you are in training often you'll improve because of the motor.

khill
12-21-10, 07:53 PM
Always keep in mind that times are not necessarily an absolute measure of what's working or not; conditions can often greatly impact performance, and depending on where you are in training often you'll improve because of the motor.

For Sure! All of these were repeated in those forms at least 2x over the last year and the times were all pretty close, except the non aero TT bike. I did get quicker at it since I rode that way the most.

Ken

davids0507
12-23-10, 07:10 PM
Hey guys,

I have an '08 Trek Madone. Anyone familiar with that bike or a lot of the non aero carbon frames on the market know that the downtubes on these bikes are pretty wide - probably 3-4x the width of the front wheel.

So my question is this: Is there any advantage to putting aero wheels on this type of bike? Let me know what you think.

-s


Ok, so I read the question and thought to myself, Hmm, good question! Then I remembered that aero wheels aren't aero because of their front profile -- they're aero because of the deep dish rims and the type of spokes; you never see a rim that is wider than the tire anyway. So the front profile of the bike is not the only thing that matters for aerodynamics. Good question.