Be more aero on your road bike ?

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strobbekoen
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by strobbekoen

Hey Everyone,

I have been doing some research on how to setup my road bike when i want to ride in an aero position on solo rides. Thought i'd share some links and pics.

I found some interesting articles by John Cobb - the guy who assisted Lance in wind tunnel testing. He is currently doing some research on the SLAM setup; this is to abandon the steep seattube angle (76-80) in favor of a more relaxed roadlike seat tube angle (72-75) to generate more power while keeping the aero benefits equal.

Here are the links:
http://www.bicyclesports.com/Slam_Setup.html
http://www.bicyclesports.com/Aero_Articles.html

My personal setup is to put on Oval Concept A910 clips. These are really well designed i think: low profile, the armrest right on top of the handlebars (it comes with raisers if you want it higher), the bar extensions tucked away UNDER the bars to keep it low; The armrests can be switched around for different reach, or angled in or out. The bars length is adjustable too.
Additionaly, i exchange my usual seatpost/saddle (which has a setback of about 2.5cm as most road seatposts have) with a zero setback post/saddle combo. The saddle is moved little forward. This yields a actual seattube angle of 74. Could remove some spacers to drop the handlebar even lower but that's not necessary in my case, i already have a substantial drop from seat to saddle.

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by Weenie


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Cyco
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by Cyco

Whilst they are some great photos of your bars strobbekoen, it is hard to comment on your aerodynamics if you are not pictured on them.

Even then air does some strange things, and unless you have spent many years in a wind tunnel of with CFD software there are very few who can "see" the wind - and they are all employees of F1 teams or aerospace companies.
Success is how far you you bounce back up after being knocked down

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whooztheman
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by whooztheman

strobbekoen
i already have a substantial drop from seat to saddle.

How much is your 'substantial' drop between armrests and seat?
"It may be near when it seems so far"

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strobbekoen
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by strobbekoen

whooztheman wrote:strobbekoen
i already have a substantial drop from seat to saddle.

How much is your 'substantial' drop between armrests and seat?


9 cm

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strobbekoen
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by strobbekoen

Cyco wrote:Whilst they are some great photos of your bars strobbekoen, it is hard to comment on your aerodynamics if you are not pictured on them.

Even then air does some strange things, and unless you have spent many years in a wind tunnel of with CFD software there are very few who can "see" the wind - and they are all employees of F1 teams or aerospace companies.


Yes, but i won't be taking it that far to do wind tunnel testing myself. I am looking for a more aero position on the road bike (not time trial) with an additional point of leverage while keeping some degree of comfort.

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whooztheman
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by whooztheman

the bigger the drop the more difficult is to ride in a classic 74 degrees position. if you want to be comfortable then try to keep the bars at the same height w/out taking out spacers. 9 cm is right on the edge between normal and big drop. show us a picture and i think that the comments will be much better. What's your elbow angle in the current position? 90 degress or more?
"It may be near when it seems so far"

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strobbekoen
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by strobbekoen

whooztheman wrote:the bigger the drop the more difficult is to ride in a classic 74 degrees position. if you want to be comfortable then try to keep the bars at the same height w/out taking out spacers. 9 cm is right on the edge between normal and big drop. show us a picture and i think that the comments will be much better. What's your elbow angle in the current position? 90 degress or more?


Thanks for your comments :)

The drop is the same as i use for riding with a standard setback seatpost. I am still experimenting with it, trying different reach/height. The armrests are smack on the bars so it's pretty much the same drop there. My elbow angle with a zero setback post is a bit over 90. Still, as you guys rightly mentioned, it's hard to check it exactly by myself. I will ask my friend to make some pics or video while i am on the bike.

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whooztheman
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by whooztheman

Measure also the bb from front of seat distance
"It may be near when it seems so far"

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strobbekoen
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by strobbekoen

whooztheman wrote:Measure also the bb from front of seat distance

with normal seatpost: 6 cm (saddle adjusted slightly forward)
with zero setback: 3 cm

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whooztheman
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by whooztheman

so, u ride with 6cm in front of the bb. am i right?
if i understood correctly... that's not so slack mate... hoping that the frame is ~74 degress.
"It may be near when it seems so far"

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whooztheman
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by whooztheman

Mate, read this http://www.slowtwitch.com/mainheadings/ ... kefit.html
and u'll find everything. It's a top article written by the Guru of bike fit Dan Empfield.
"It may be near when it seems so far"

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whooztheman
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by whooztheman

Now, the strange thing of searching tech info and articles.
After everybody -of course including me- finishes the search and has found the 'right' info, they always come back to the basics... that is position yourself by "feel". The human mind IS the best computer [for someone that knows few things about cycling].
"It may be near when it seems so far"

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strobbekoen
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by strobbekoen

whooztheman wrote:so, u ride with 6cm in front of the bb. am i right?
if i understood correctly... that's not so slack mate... hoping that the frame is ~74 degress.


Ok i did some exact measurements with a plumb.

From the top of the seat, intersecting with the center of seattube i measure a distance of 21cm behind bottom bracket. BB to top of seat is 75cm.
-> sin(a) = 21/75 => a = 16.26 => seattube angle = 90-16.26 = 73.74
according giant the seattube angle for a M size is 73.5 so that's pretty accurate.

If my saddle is 3cm more forward
sin(a) = 18/75 => a = 13.88 => effective seattube angle = 76.12

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whooztheman
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by whooztheman

Read the article and y'll fix it perfectly!
Don't touch anything yet, do very small adjustments each time, let yr body adjust, stay positive!
RIDE, RIDE, RIDE!
"It may be near when it seems so far"

by Weenie


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strobbekoen
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by strobbekoen

Measured with a plumb from top of saddle to floor, and top of armrests to floor, the difference is 8cm

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