Aero spokes?

wrote:
On Apr 21, 1:38 pm, "
wrote:
Hi All,

I'm trying to puzzle together a wheelset using some rims from a pre-
built set which I broke the freehub on. My problem is finding
inexpensive, durable, serviceable hubs with aero drilling. So I am
considering building up with round spokes.

So my question is, on a 50mm deep rim with 24 spokes, how much will I
be giving away switching from 2.3mm bladed, to butted 1.5mm round
spokes?

Joseph

If you mean, "how much slower will I be?", I doubt you'll ever feel
the difference.

I went from oval front spokes to round ones on my touring bike.
Understand, this is the bike I use (unloaded, of course) for most of
my recreational rides. There was probably some difference, but I
couldn't detect it.

If you're planning on racing, I suppose there's a bike performance
calculator website out there that covers spoke types, and can give an
approximate time advantage or disadvantage. Put Carl Fogel on the
project.


but /you/ are the engineering professor krygowski. /you/ have access to
testing gear. /you/ have a bunch of students anxious to learn from your
superior knowledge and example. quit this opinionated idiot blathering
and go get some numbers out there. put an accelerometer on your carbon
fork while you're at it too.

wrote:
Hi All,

I'm trying to puzzle together a wheelset using some rims from a pre-
built set which I broke the freehub on. My problem is finding
inexpensive, durable, serviceable hubs with aero drilling. So I am
considering building up with round spokes.

So my question is, on a 50mm deep rim with 24 spokes, how much will I
be giving away switching from 2.3mm bladed, to butted 1.5mm round
spokes?

Joseph

for a heavy guy, 1.5mm spokes, #24, might be a little too flexy. stick
to 2.0mm's. my mavic cosmos have #24 2.0mm's and they're fine under my
210lbs.

On Mon, 21 Apr 2008 18:46:29 -0700 (PDT), wrote:

On Apr 21, 1:38 pm, "
wrote:
Hi All,

I'm trying to puzzle together a wheelset using some rims from a pre-
built set which I broke the freehub on. My problem is finding
inexpensive, durable, serviceable hubs with aero drilling. So I am
considering building up with round spokes.

So my question is, on a 50mm deep rim with 24 spokes, how much will I
be giving away switching from 2.3mm bladed, to butted 1.5mm round
spokes?

Joseph

If you mean, "how much slower will I be?", I doubt you'll ever feel
the difference.

I went from oval front spokes to round ones on my touring bike.
Understand, this is the bike I use (unloaded, of course) for most of
my recreational rides. There was probably some difference, but I
couldn't detect it.

If you're planning on racing, I suppose there's a bike performance
calculator website out there that covers spoke types, and can give an
approximate time advantage or disadvantage. Put Carl Fogel on the
project.

- Frank Krygowski

Dear Frank & Joseph,

Up to 10 watts to spin a wheel 30 mph. And sometimes oval does better
than bladed:

"Perhaps the most noticeable feature of this graph is the very high
wattage of the round spoked 46mm deep wheel. Requiring more than 10
additional watts to spin when compared to the almost identical bladed
spoke 46mm deep wheel, with which it shared nearly the identical drag
curve! Also, of note is the improvement in performance of the
historical 303’s, with the oval spokes proving to be slightly better
than the bladed spokes when combined with the same rim."

http://www.zipp.com/LinkClick.aspx?f...A%3d&tabid=140

The rear wheel will not benefit as much because it's in the lee.

This calculator has been updated:
http://bikecalculator.com/veloUS.html

With on-the-drops and tubulars, 495 watts produces 30.00 mph, 39.99
minutes for 20 miles.

The same, but with 485 watts produces 29.79 mph, 40.28 minutes for 20
miles.

That's a savings of 0.29 minutes, or about 17 seconds.

If for some reason you ride at less than 30 mph, the advantage will be
smaller, since wind drag rises wildly as speed increases.

That is, at lower speeds, far less power is wasted spinning the
awkward windmill of a bicycle wheel, whose top spoke is momentarily
doing twice the bicycle's speed through the air. (At 30 mph, the upper
spoke is doing 60 mph versus the wind, while the bottom spoke is
motionless.)

Of course, if your elbows aren't bent just right, you'll lose far more
than the theoretical advantage of the spokes. The biggest wind drag
problem is the rider. Aerobars offer far more wind drag advantage than
spokes.

Cheers,

Carl Fogel

On Apr 21, 11:38*am, "
wrote:
So my question is, on a 50mm deep rim with 24 spokes, how much will I
be giving away switching from 2.3mm bladed, to butted 1.5mm round
spokes?

Get CX-Rays or Aerolites... any hub will do.

On Apr 22, 5:43*am, wrote:
On Mon, 21 Apr 2008 18:46:29 -0700 (PDT), wrote:
On Apr 21, 1:38 pm, "
wrote:
Hi All,

I'm trying to puzzle together a wheelset using some rims from a pre-
built set which I broke the freehub on. My problem is finding
inexpensive, durable, serviceable hubs with aero drilling. So I am
considering building up with round spokes.

So my question is, on a 50mm deep rim with 24 spokes, how much will I
be giving away switching from 2.3mm bladed, to butted 1.5mm round
spokes?

Joseph

If you mean, "how much slower will I be?", I doubt you'll ever feel
the difference.

I went from oval front spokes to round ones on my touring bike.
Understand, this is the bike I use (unloaded, of course) for most of
my recreational rides. *There was probably some difference, but I
couldn't detect it.

If you're planning on racing, I suppose there's a bike performance
calculator website out there that covers spoke types, and can give an
approximate time advantage or disadvantage. *Put Carl Fogel on the
project.

- Frank Krygowski

Dear Frank & Joseph,

Up to 10 watts to spin a wheel 30 mph. And sometimes oval does better
than bladed:

"Perhaps the most noticeable feature of this graph is the very high
wattage of the round spoked 46mm deep wheel. Requiring more than 10
additional watts to spin when compared to the almost identical bladed
spoke 46mm deep wheel, with which it shared nearly the identical drag
curve! Also, of note is the improvement in performance of the
historical 303’s, with the oval spokes proving to be slightly better
than the bladed spokes when combined with the same rim."

http://www.zipp.com/LinkClick.aspx?f...A%3d&tabid=140

The rear wheel will not benefit as much because it's in the lee.

This calculator has been updated:
*http://bikecalculator.com/veloUS.html

With on-the-drops and tubulars, 495 watts produces 30.00 mph, 39.99
minutes for 20 miles.

The same, but with 485 watts produces 29.79 mph, 40.28 minutes for 20
miles.

That's a savings of 0.29 minutes, or about 17 seconds.

If for some reason you ride at less than 30 mph, the advantage will be
smaller, since wind drag rises wildly as speed increases.

That is, at lower speeds, far less power is wasted spinning the
awkward windmill of a bicycle wheel, whose top spoke is momentarily
doing twice the bicycle's speed through the air. (At 30 mph, the upper
spoke is doing 60 mph versus the wind, while the bottom spoke is
motionless.)

Of course, if your elbows aren't bent just right, you'll lose far more
than the theoretical advantage of the spokes. The biggest wind drag
problem is the rider. Aerobars offer far more wind drag advantage than
spokes.

Cheers,

Carl Fogel

These are race wheels intended for ITTs and for road races. It is in
the range of 23-29mph that I expect these to confer advantage.

From the Zipp article it seems there is essentially no reason to use
wide bladed spokes. I had been under the impression that spokes like
CX-Ray and DT Aerolite were inferior aerodynamically to bladed. I am
happy to be wrong about that.

Joseph

On Apr 21, 11:43 pm, wrote:
On Mon, 21 Apr 2008 18:46:29 -0700 (PDT), wrote:


If you're planning on racing, I suppose there's a bike performance
calculator website out there that covers spoke types, and can give an
approximate time advantage or disadvantage. Put Carl Fogel on the
project.

- Frank Krygowski

Dear Frank & Joseph,

Up to 10 watts to spin a wheel 30 mph. And sometimes oval does better
than bladed...


Thanks, Carl. I knew you were the man for the job.

- Frank Krygowski

On Apr 21, 11:38*am, "
wrote:
Hi All,

I'm trying to puzzle together a wheelset using some rims from a pre-
built set which I broke the freehub on. My problem is finding
inexpensive, durable, serviceable hubs with aero drilling. So I am
considering building up with round spokes.

So my question is, on a 50mm deep rim with 24 spokes, how much will I
be giving away switching from 2.3mm bladed, to butted 1.5mm round
spokes?

Joseph

There is a tool with a hole and guide in it where you can slot any
hub. Pin from guide in spoke hole of the hub, teeny drill bit thru
guide hole= slotted hubs.

On Apr 21, 12:59*pm, "
wrote:
On Apr 21, 8:25*pm, daveornee daveornee.388...@no-



mx.forums.cyclingforums.com wrote:
Wrote: Hi All,

I'm trying to puzzle together a wheelset using some rims from a pre-
built set which I broke the freehub on. My problem is finding
inexpensive, durable, serviceable hubs with aero drilling. So I am
considering building up with round spokes.

So my question is, on a 50mm deep rim with 24 spokes, how much will I
be giving away switching from 2.3mm bladed, to butted 1.5mm round
spokes?

Joseph

Have you considered Sapim CX-Ray spokes whic fit in standard hub holes?

--
daveornee

Yes, but at $6 a pop locally they are too expensive.

Joseph

PLUS these and other 'oval' spokes start life as really thin spokes,
unlike most true bladed, which start as 14g spokes. Thin spokes, few
spokes, light-ish rim- three strikes kinda deal.

On Apr 21, 9:37*pm, jim beam wrote:
for a heavy guy, 1.5mm spokes, #24, might be a little too flexy. *stick
to 2.0mm's. *my mavic cosmos have #24 2.0mm's and they're fine under my
210lbs.

Cosmos rim is very shallow, though. Since this is a 50mm rim, CX-Rays
should be fine with 24... at least on the front. What rim is it? The
Gigantex clones?

Wrote:
Hi All,

I'm trying to puzzle together a wheelset using some rims from a pre-
built set which I broke the freehub on. My problem is finding
inexpensive, durable, serviceable hubs with aero drilling.

You might want to check out www.cyclecomponents.com. They might not be
able to beat DO-s offer, but they can do better than your $6 at least.
CC are based in Sweden, so shipping shouldn't be too bad either.


--
dabac