HED and Crosswinds

On Feb 9, 2:00 pm, "bicycle_disciple" <[email hidden]>
wrote:
<snip>

Quoted message said:

How optimum can 50mm be? Has anyone tested this before, any literature
out there tabulating what happens with increasing rim depth. If anyone
has experience, with these wheels, or any similar aero, how much ride
quality , like speed, handling etc is affected by windy conditions?

It sounds like marketingspeak to me. Certainly wheels with greater
side area are going to be affected by crosswinds, but handling is
pretty hard to quantify. Other variables, such as frame geometry,
rider preference, and rider skill (to begin with) come into play.

Jeff

On Feb 9, 4:00 pm, "bicycle_disciple" <[email hidden]>

Quoted message said:

The subject of this post is HED Jet 50, an aerodynamic wheel from HED
with 50 mm rim aero profile.http://www.hedcycling.com/wheels/
jet50.php

Maybe this has been discussed a lot. Some aero wheels have low
profile, while others are 'super aero' with deep or very deep profile.
But with more rim depth, comes the problem of crosswinds affecting
ride quality (am i right here, maybe someone should paraphrase me).

So where is the cutoff between a 'clean and decent' aero performance
and the point where the wind comes significantly into the equation? Is
there anything at all as "airproof"?

Quoting from the HED Jet 50 product website, "..Shorter rims do not
offer enough drag reduction, and taller rims can sometimes present
handling problems if the wind is strong." And then comes their case
for an optimum rim depth of 50mm, which is designed into the Jet 50.

How optimum can 50mm be? Has anyone tested this before, any literature
out there tabulating what happens with increasing rim depth. If anyone
has experience, with these wheels, or any similar aero, how much ride
quality , like speed, handling etc is affected by windy conditions?

You'll enlighten me greatly with your ideas, but feel free to support
anything you say with tech. literature.

Thanks,

Ron
Student, Mech.Engg

Could someone measure the aerodynamic torque about the steering axis
in various side winds? Seems like this could be done in a wind tunnel
- multiply the sideways component of drag by the distance between the
center of pressure and the steering axis... Then compare various
wheels.

Under steady state conditions a rider could provide a steady counter-
torque to maintain course, but in variable wind conditions (even a
little gusty??) the cross winds might change quickly enough to make
deeper front wheels feel less steady?

There was a wheel-test in the German magazine Velomotion in January.
They included also a test of side-wind effect. Somebody was quoting
the test in 3athlon forum. Here are some results: (unit = Newtons)

Zipp 404 15.8
Easton Tempest II 15.9
Lightweight (12-spoke?) 16.5
Zipp 808 20.4
Xentis TT 26.5

I just subscribed for the Mag. This test in January was for tubular
wheels, another for clinchers will be available in March. I could try
to write a short summary of the tests, in March.

Finno said:

There was a wheel-test in the German magazine Velomotion in January.
They included also a test of side-wind effect. Somebody was quoting
the test in 3athlon forum. Here are some results: (unit = Newtons)

Zipp 404 15.8
Easton Tempest II 15.9
Lightweight (12-spoke?) 16.5
Zipp 808 20.4
Xentis TT 26.5

I just subscribed for the Mag. This test in January was for tubular
wheels, another for clinchers will be available in March. I could try
to write a short summary of the tests, in March.

Yes, please go ahead and do that. Zipps and HED's should be comparable.

Found this site with discussions about the Velomotion wheel-test.

http://fairwheelbikes.com/forum/viewtopic.php?t=2329

Cheers

Finno

Hey,

If you find any data on the new Hed Jet wheels, let me know.

Ron

Finno said:

Found this site with discussions about the Velomotion wheel-test.

http://fairwheelbikes.com/forum/viewtopic.php?t=2329

Cheers

Finno