Re: Durable Rims for Road Wheels - Recommendations?

Quoted message said:

On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
<[email hidden]>

Quoted message said:

-----BEGIN PGP SIGNED MESSAGE-----

In article <[email hidden]>,

Quoted message said:

[email hidden] wrote:
> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
>

Back to the first point I raise, you still claim that because it's only
a 3 or 5% change, it's a surprise that Jim feels it, an argument which
has a huge gap :-)

_ It's also pointless unless Jim is using exactly the same rims
and tires. My guess is that the difference he notices has way
more to do with rim depth and shape than the number of spokes.

_ Booker C. Bense

Dear Carl,

Quoted message said:

A slightly wider or thinner ring (different rims) might not make much
difference to this fan in a side wind.

What are your numbers behind this statement?

Doug

Quoted message said:

Quoted message said:

On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
<[email hidden]>

Quoted message said:

-----BEGIN PGP SIGNED MESSAGE-----

In article <[email hidden]>,
<[email hidden]> wrote:
>[email hidden] wrote:
>> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
>>
>
>Back to the first point I raise, you still claim that because it's only
>a 3 or 5% change, it's a surprise that Jim feels it, an argument which
>has a huge gap :-)
>

_ It's also pointless unless Jim is using exactly the same rims
and tires. My guess is that the difference he notices has way
more to do with rim depth and shape than the number of spokes.

_ Booker C. Bense

Dear Carl,

Quoted message said:

A slightly wider or thinner ring (different rims) might not make much
difference to this fan in a side wind.

What are your numbers behind this statement?

Doug

Dear Doug,

A ring/rim has the effectively same side resistance, whether it's
spinning or not.

(Yes, there's some drag on the smooth surface, but it's trivial in
this case. This is why a disk wheel reduces drag so much over exposed
spokes.)

A blade's resistance increases as it spins.

(How well thin round spokes function as blades is the question.)

If you blow hard through a handy computer fan in the right direction,
you'll notice the blades slowing. Blow on a spinning ring and not much
will happen.

The bicycle wheel, it's worth repeating, complicates things by not
really functioning like any normal propellor or fan.

When a bicycle moves at 20 mph, the top end of the top "blade" is
doing about 40 mph forward and its bottom end is doing about 20 mph.

Meanwhile, the bottom of the bottom "blade" is doing about 0 mph,
while its upper end is doing about 20 mph forward.

The entire blade pointing dead forward is moving 20 mph forward, with
its far end moving 20 mph downward, but heavily sheltered by the rim
and tire.

The entire blade pointing dead backward is moving 20 mph forward, with
its far end moving about 20 mph upward through a turbulent mess.

Plus, the blades are all sticking out at ang angle from the plane of
the rim.

Cheers,

Carl Fogel

Quoted message said:

Quoted message said:

Quoted message said:

On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
<[email hidden]>
wrote:

>-----BEGIN PGP SIGNED MESSAGE-----
>
>In article <[email hidden]>,
> <[email hidden]> wrote:
>>[email hidden] wrote:
>>> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
>>>
>>
>>Back to the first point I raise, you still claim that because it's only
>>a 3 or 5% change, it's a surprise that Jim feels it, an argument which
>>has a huge gap :-)
>>
>
>_ It's also pointless unless Jim is using exactly the same rims
>and tires. My guess is that the difference he notices has way
>more to do with rim depth and shape than the number of spokes.
>
>_ Booker C. Bense

Dear Carl,

Quoted message said:

A slightly wider or thinner ring (different rims) might not make much
difference to this fan in a side wind.

What are your numbers behind this statement?

Doug

Dear Doug,

A ring/rim has the effectively same side resistance, whether it's
spinning or not.

Yes, Dear Carl, but... Jim is feeling the resistance that the wheel
would have even were it not spinning. Which is five times the
resistance that comes from the spokes, according to your own
calculations of surface area. Added to that, he is also feeling any
increases or differences due to forward or rotational speed.

You've come full circle in your arguments - you yourself counted that
79,800 mm^2 in your argument that the change is only 3-5%.

Since the area of the rim+tire is approx 4 times that of the spokes,
Jim will surely find it (a change in tire or rim size) affecting how
much harder it is to control in a crosswind.

Remember, it was a change of wheel resulted in whatever that Jim felt,
not a change in bike speed.

Cheers,
Doug

Quoted message said:

Quoted message said:

Quoted message said:

[email hidden] wrote:
> On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
> <[email hidden]>
> wrote:
>
> >-----BEGIN PGP SIGNED MESSAGE-----
> >
> >In article <[email hidden]>,
> > <[email hidden]> wrote:
> >>[email hidden] wrote:
> >>> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
> >>>
> >>
> >>Back to the first point I raise, you still claim that because it's only
> >>a 3 or 5% change, it's a surprise that Jim feels it, an argument which
> >>has a huge gap :-)
> >>
> >
> >_ It's also pointless unless Jim is using exactly the same rims
> >and tires. My guess is that the difference he notices has way
> >more to do with rim depth and shape than the number of spokes.
> >
> >_ Booker C. Bense

Dear Carl,

> A slightly wider or thinner ring (different rims) might not make much
> difference to this fan in a side wind.

What are your numbers behind this statement?

Doug

Dear Doug,

A ring/rim has the effectively same side resistance, whether it's
spinning or not.

Yes, Dear Carl, but... Jim is feeling the resistance that the wheel
would have even were it not spinning. Which is five times the
resistance that comes from the spokes, according to your own
calculations of surface area. Added to that, he is also feeling any
increases or differences due to forward or rotational speed.

You've come full circle in your arguments - you yourself counted that
79,800 mm^2 in your argument that the change is only 3-5%.

Since the area of the rim+tire is approx 4 times that of the spokes,
Jim will surely find it (a change in tire or rim size) affecting how
much harder it is to control in a crosswind.

Remember, it was a change of wheel resulted in whatever that Jim felt,
not a change in bike speed.

Cheers,
Doug

Doug,

Jim feels a strong difference at roughly the same speed between two
front wheels in gusty side winds.

If the effect of the side wind is just a matter of surface area, then
the feeling is likely to an illusion--expection coupled with highly
variable winds. After all the difference in surface area appears to be
only 3% to 5%.

But if the effect of the side wind is more a matter of the number of
blades whirling in the wind like a fan, then the rim surface becomes
trivial and the 25% reduction in the number of blades suggests that
Jim is feeling a clear effect.

Viewed from the side, whirling fan blades are obviously different than
a smooth, spinning rim surface, so the question is whether thin spokes
in the peculiar turbulence of the wheel generate enough force to have
a significant effect.

The blades on the fan in your computer have an effect, but not enough
to affect a rider's balance. The "blades" in a wheel are much thinner,
are shaped differently, sweep a much larger area, and are very
peculiar in that they are rolling instead of stationary.

Do they have a big enough aerodynamic effect to explain what Jim
feels? I don't know. But those are the two possible explanations that
I can see.

If you find a wind tunnel test for gusty wind effects, let us know.

Cheers,

Carl Fogel

Quoted message said:

Quoted message said:

Quoted message said:

On 21 Aug 2006 15:32:26 -0700, [email hidden] wrote:

>[email hidden] wrote:
>> On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
>> <[email hidden]>
>> wrote:
>>
>> >-----BEGIN PGP SIGNED MESSAGE-----
>> >
>> >In article <[email hidden]>,
>> > <[email hidden]> wrote:
>> >>[email hidden] wrote:
>> >>> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
>> >>>
>> >>
>> >>Back to the first point I raise, you still claim that because it's only
>> >>a 3 or 5% change, it's a surprise that Jim feels it, an argument which
>> >>has a huge gap :-)
>> >>
>> >
>> >_ It's also pointless unless Jim is using exactly the same rims
>> >and tires. My guess is that the difference he notices has way
>> >more to do with rim depth and shape than the number of spokes.
>> >
>> >_ Booker C. Bense
>
>Dear Carl,
>
>> A slightly wider or thinner ring (different rims) might not make much
>> difference to this fan in a side wind.
>
>What are your numbers behind this statement?
>
>Doug

Dear Doug,

A ring/rim has the effectively same side resistance, whether it's
spinning or not.

Yes, Dear Carl, but... Jim is feeling the resistance that the wheel
would have even were it not spinning. Which is five times the
resistance that comes from the spokes, according to your own
calculations of surface area. Added to that, he is also feeling any
increases or differences due to forward or rotational speed.

You've come full circle in your arguments - you yourself counted that
79,800 mm^2 in your argument that the change is only 3-5%.

Since the area of the rim+tire is approx 4 times that of the spokes,
Jim will surely find it (a change in tire or rim size) affecting how
much harder it is to control in a crosswind.

Remember, it was a change of wheel resulted in whatever that Jim felt,
not a change in bike speed.

Cheers,
Doug

Doug,

Jim feels a strong difference at roughly the same speed between two
front wheels in gusty side winds.

If the effect of the side wind is just a matter of surface area, then
the feeling is likely to an illusion--expection coupled with highly
variable winds. After all the difference in surface area appears to be
only 3% to 5%.

But if the effect of the side wind is more a matter of the number of
blades whirling in the wind like a fan, then the rim surface becomes
trivial and the 25% reduction in the number of blades suggests that
Jim is feeling a clear effect.

Viewed from the side, whirling fan blades are obviously different than
a smooth, spinning rim surface, so the question is whether thin spokes
in the peculiar turbulence of the wheel generate enough force to have
a significant effect.

The blades on the fan in your computer have an effect, but not enough
to affect a rider's balance. The "blades" in a wheel are much thinner,
are shaped differently, sweep a much larger area, and are very
peculiar in that they are rolling instead of stationary.

Do they have a big enough aerodynamic effect to explain what Jim
feels? I don't know. But those are the two possible explanations that
I can see.

If you find a wind tunnel test for gusty wind effects, let us know.

Very simply, because that's all I can do, for all practical purposes the area of
an object includes the mass of roiled air attached to it. If the spoke has less
drag going forward it will have a much smaller profile to the side winds. The
crosswind "sees" the wheel components as a single piece with the wad of dirty
air in and around it.

Need more, ask an aerodynamicist and be prepared to take on a new study.

Ron

RonSonic said:

Quoted message said:

Quoted message said:

[email hidden] wrote:
> On 21 Aug 2006 15:32:26 -0700, [email hidden] wrote:
>
> >[email hidden] wrote:
> >> On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
> >> <[email hidden]>
> >> wrote:
> >>
> >> >-----BEGIN PGP SIGNED MESSAGE-----
> >> >
> >> >In article <[email hidden]>,
> >> > <[email hidden]> wrote:
> >> >>[email hidden] wrote:
> >> >>> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
> >> >>>
> >> >>
> >> >>Back to the first point I raise, you still claim that because it's only
> >> >>a 3 or 5% change, it's a surprise that Jim feels it, an argument which
> >> >>has a huge gap :-)
> >> >>
> >> >
> >> >_ It's also pointless unless Jim is using exactly the same rims
> >> >and tires. My guess is that the difference he notices has way
> >> >more to do with rim depth and shape than the number of spokes.
> >> >
> >> >_ Booker C. Bense
> >
> >Dear Carl,
> >
> >> A slightly wider or thinner ring (different rims) might not make much
> >> difference to this fan in a side wind.
> >
> >What are your numbers behind this statement?
> >
> >Doug
>
> Dear Doug,
>
> A ring/rim has the effectively same side resistance, whether it's
> spinning or not.
>

Yes, Dear Carl, but... Jim is feeling the resistance that the wheel
would have even were it not spinning. Which is five times the
resistance that comes from the spokes, according to your own
calculations of surface area. Added to that, he is also feeling any
increases or differences due to forward or rotational speed.

You've come full circle in your arguments - you yourself counted that
79,800 mm^2 in your argument that the change is only 3-5%.

Since the area of the rim+tire is approx 4 times that of the spokes,
Jim will surely find it (a change in tire or rim size) affecting how
much harder it is to control in a crosswind.

Remember, it was a change of wheel resulted in whatever that Jim felt,
not a change in bike speed.

Cheers,
Doug

Doug,

Jim feels a strong difference at roughly the same speed between two
front wheels in gusty side winds.

If the effect of the side wind is just a matter of surface area, then
the feeling is likely to an illusion--expection coupled with highly
variable winds. After all the difference in surface area appears to be
only 3% to 5%.

But if the effect of the side wind is more a matter of the number of
blades whirling in the wind like a fan, then the rim surface becomes
trivial and the 25% reduction in the number of blades suggests that
Jim is feeling a clear effect.

Viewed from the side, whirling fan blades are obviously different than
a smooth, spinning rim surface, so the question is whether thin spokes
in the peculiar turbulence of the wheel generate enough force to have
a significant effect.

The blades on the fan in your computer have an effect, but not enough
to affect a rider's balance. The "blades" in a wheel are much thinner,
are shaped differently, sweep a much larger area, and are very
peculiar in that they are rolling instead of stationary.

Do they have a big enough aerodynamic effect to explain what Jim
feels? I don't know. But those are the two possible explanations that
I can see.

If you find a wind tunnel test for gusty wind effects, let us know.

Very simply, because that's all I can do, for all practical purposes the area of
an object includes the mass of roiled air attached to it. If the spoke has less
drag going forward it will have a much smaller profile to the side winds. The
crosswind "sees" the wheel components as a single piece with the wad of dirty
air in and around it.

Need more, ask an aerodynamicist and be prepared to take on a new study.

Ron

Dear Ron,

A solid disk front is universally agreed to be a bad idea in a
crosswind.

So the question still remains: does a 32-spoke wheel look
significantly more turbulent to a gusty crosswind than a 24-spoke
wheel as Jim rides across the Golden Gate?

That is, how much dirtier is the wad of air whipped up inside a 32
spoke wheel, versus a 24-spoke wheel?

Cheers,

Carl Fogel

Quoted message said:

RonSonic said:

Quoted message said:

On 21 Aug 2006 16:06:43 -0700, [email hidden] wrote:

>[email hidden] wrote:
>> On 21 Aug 2006 15:32:26 -0700, [email hidden] wrote:
>>
>> >[email hidden] wrote:
>> >> On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
>> >> <[email hidden]>
>> >> wrote:
>> >>
>> >> >-----BEGIN PGP SIGNED MESSAGE-----
>> >> >
>> >> >In article <[email hidden]>,
>> >> > <[email hidden]> wrote:
>> >> >>[email hidden] wrote:
>> >> >>> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
>> >> >>>
>> >> >>
>> >> >>Back to the first point I raise, you still claim that because it's only
>> >> >>a 3 or 5% change, it's a surprise that Jim feels it, an argument which
>> >> >>has a huge gap :-)
>> >> >>
>> >> >
>> >> >_ It's also pointless unless Jim is using exactly the same rims
>> >> >and tires. My guess is that the difference he notices has way
>> >> >more to do with rim depth and shape than the number of spokes.
>> >> >
>> >> >_ Booker C. Bense
>> >
>> >Dear Carl,
>> >
>> >> A slightly wider or thinner ring (different rims) might not make much
>> >> difference to this fan in a side wind.
>> >
>> >What are your numbers behind this statement?
>> >
>> >Doug
>>
>> Dear Doug,
>>
>> A ring/rim has the effectively same side resistance, whether it's
>> spinning or not.
>>
>
>Yes, Dear Carl, but... Jim is feeling the resistance that the wheel
>would have even were it not spinning. Which is five times the
>resistance that comes from the spokes, according to your own
>calculations of surface area. Added to that, he is also feeling any
>increases or differences due to forward or rotational speed.
>
>You've come full circle in your arguments - you yourself counted that
>79,800 mm^2 in your argument that the change is only 3-5%.
>
>Since the area of the rim+tire is approx 4 times that of the spokes,
>Jim will surely find it (a change in tire or rim size) affecting how
>much harder it is to control in a crosswind.
>
>Remember, it was a change of wheel resulted in whatever that Jim felt,
>not a change in bike speed.
>
>Cheers,
>Doug

Doug,

Jim feels a strong difference at roughly the same speed between two
front wheels in gusty side winds.

If the effect of the side wind is just a matter of surface area, then
the feeling is likely to an illusion--expection coupled with highly
variable winds. After all the difference in surface area appears to be
only 3% to 5%.

But if the effect of the side wind is more a matter of the number of
blades whirling in the wind like a fan, then the rim surface becomes
trivial and the 25% reduction in the number of blades suggests that
Jim is feeling a clear effect.

Viewed from the side, whirling fan blades are obviously different than
a smooth, spinning rim surface, so the question is whether thin spokes
in the peculiar turbulence of the wheel generate enough force to have
a significant effect.

The blades on the fan in your computer have an effect, but not enough
to affect a rider's balance. The "blades" in a wheel are much thinner,
are shaped differently, sweep a much larger area, and are very
peculiar in that they are rolling instead of stationary.

Do they have a big enough aerodynamic effect to explain what Jim
feels? I don't know. But those are the two possible explanations that
I can see.

If you find a wind tunnel test for gusty wind effects, let us know.

Very simply, because that's all I can do, for all practical purposes the area of
an object includes the mass of roiled air attached to it. If the spoke has less
drag going forward it will have a much smaller profile to the side winds. The
crosswind "sees" the wheel components as a single piece with the wad of dirty
air in and around it.

Need more, ask an aerodynamicist and be prepared to take on a new study.

Ron

Dear Ron,

A solid disk front is universally agreed to be a bad idea in a
crosswind.

So the question still remains: does a 32-spoke wheel look
significantly more turbulent to a gusty crosswind than a 24-spoke
wheel as Jim rides across the Golden Gate?

That is, how much dirtier is the wad of air whipped up inside a 32
spoke wheel, versus a 24-spoke wheel?

Empirically, enough.

Is it just the spoke count? Apparently not.

Ron

RonSonic said:

Quoted message said:

RonSonic said:

On Mon, 21 Aug 2006 19:18:08 -0600, [email hidden] wrote:

>On 21 Aug 2006 16:06:43 -0700, [email hidden] wrote:
>
>>[email hidden] wrote:
>>> On 21 Aug 2006 15:32:26 -0700, [email hidden] wrote:
>>>
>>> >[email hidden] wrote:
>>> >> On Mon, 21 Aug 2006 21:24:38 +0000 (UTC), Booker C. Bense
>>> >> <[email hidden]>
>>> >> wrote:
>>> >>
>>> >> >-----BEGIN PGP SIGNED MESSAGE-----
>>> >> >
>>> >> >In article <[email hidden]>,
>>> >> > <[email hidden]> wrote:
>>> >> >>[email hidden] wrote:
>>> >> >>> On 17 Aug 2006 16:16:09 -0700, [email hidden] wrote:
>>> >> >>>
>>> >> >>
>>> >> >>Back to the first point I raise, you still claim that because it's only
>>> >> >>a 3 or 5% change, it's a surprise that Jim feels it, an argument which
>>> >> >>has a huge gap :-)
>>> >> >>
>>> >> >
>>> >> >_ It's also pointless unless Jim is using exactly the same rims
>>> >> >and tires. My guess is that the difference he notices has way
>>> >> >more to do with rim depth and shape than the number of spokes.
>>> >> >
>>> >> >_ Booker C. Bense
>>> >
>>> >Dear Carl,
>>> >
>>> >> A slightly wider or thinner ring (different rims) might not make much
>>> >> difference to this fan in a side wind.
>>> >
>>> >What are your numbers behind this statement?
>>> >
>>> >Doug
>>>
>>> Dear Doug,
>>>
>>> A ring/rim has the effectively same side resistance, whether it's
>>> spinning or not.
>>>
>>
>>Yes, Dear Carl, but... Jim is feeling the resistance that the wheel
>>would have even were it not spinning. Which is five times the
>>resistance that comes from the spokes, according to your own
>>calculations of surface area. Added to that, he is also feeling any
>>increases or differences due to forward or rotational speed.
>>
>>You've come full circle in your arguments - you yourself counted that
>>79,800 mm^2 in your argument that the change is only 3-5%.
>>
>>Since the area of the rim+tire is approx 4 times that of the spokes,
>>Jim will surely find it (a change in tire or rim size) affecting how
>>much harder it is to control in a crosswind.
>>
>>Remember, it was a change of wheel resulted in whatever that Jim felt,
>>not a change in bike speed.
>>
>>Cheers,
>>Doug
>
>Doug,
>
>Jim feels a strong difference at roughly the same speed between two
>front wheels in gusty side winds.
>
>If the effect of the side wind is just a matter of surface area, then
>the feeling is likely to an illusion--expection coupled with highly
>variable winds. After all the difference in surface area appears to be
>only 3% to 5%.
>
>But if the effect of the side wind is more a matter of the number of
>blades whirling in the wind like a fan, then the rim surface becomes
>trivial and the 25% reduction in the number of blades suggests that
>Jim is feeling a clear effect.
>
>Viewed from the side, whirling fan blades are obviously different than
>a smooth, spinning rim surface, so the question is whether thin spokes
>in the peculiar turbulence of the wheel generate enough force to have
>a significant effect.
>
>The blades on the fan in your computer have an effect, but not enough
>to affect a rider's balance. The "blades" in a wheel are much thinner,
>are shaped differently, sweep a much larger area, and are very
>peculiar in that they are rolling instead of stationary.
>
>Do they have a big enough aerodynamic effect to explain what Jim
>feels? I don't know. But those are the two possible explanations that
>I can see.
>
>If you find a wind tunnel test for gusty wind effects, let us know.

Very simply, because that's all I can do, for all practical purposes the area of
an object includes the mass of roiled air attached to it. If the spoke has less
drag going forward it will have a much smaller profile to the side winds. The
crosswind "sees" the wheel components as a single piece with the wad of dirty
air in and around it.

Need more, ask an aerodynamicist and be prepared to take on a new study.

Ron

Dear Ron,

A solid disk front is universally agreed to be a bad idea in a
crosswind.

So the question still remains: does a 32-spoke wheel look
significantly more turbulent to a gusty crosswind than a 24-spoke
wheel as Jim rides across the Golden Gate?

That is, how much dirtier is the wad of air whipped up inside a 32
spoke wheel, versus a 24-spoke wheel?

Empirically, enough.

Is it just the spoke count? Apparently not.

Ron

Dear RonSonic

Hard to keep the Ron's straight here.

Elsewhere in this thread, Ron Ruff found a very nice link to a side
force article with a graph well down that suggests that spoke count is
much less important than rim differences:

http://groups.google.com/group/rec.bicycles.tech/msg/c01ecef22aeb16cb

The link above to my post includes Ron Ruff's post, link, and the
related link.

Cheers,

Carl Fogel