Wheel building questions

Chalo wrote:
jim beam wrote

i'm down to 200, & i'm still riding 16 spoke wheels to no detriment.


That depends on what you consider a detriment. Low spoke count wheels
are, at best, no stronger than wheels of equal weight with
conventional spoke counts. They are also more flexible and a lot more
difficult to true and service. They become unrideable from damage
that is tolerable to a conventional wheel.

--All this in exchange for benefits that lie in the range between
unmeasurable and insignificant.

Chalo Colina

well, there's one huge advantage of low spoke count wheels - that of
wind resistance. let's ignore the arguments about "makes no difference
to speed" a moment and look at a much more tangible example. i commute
by bike most days by bike across the golden gate bridge to san
francisco. it's almost always subject to significant cross wind on both
the approaches and on the bridge itself. riding a normal 32 spoke
wheelset, my bike is somewhat squirrely when the wind is bad. riding 16
spoke wheels however, the effect of cross winds is substantially less.
my low spoke wheels are shimano r540's and they have much deeper rims
than my ma3 32 spokers, so if rim alone were the factor, the ma3's would
be the less susceptible ride. given the fact that the r540's are
better, it can only be that the lower wind resistance /is/ a result of
lower spoke count, yes? and i'm not talking a little gust of wind here
- i'm talking gnarly stuff that blows the glasses off your face - as has
happened. trust me, in those conditions, you want wheels which you
/don't/ have to wrestle with the whole way home.

jim beam wrote:

well, there's one huge advantage of low spoke count wheels - that of
wind resistance.
snip
it's almost always subject to significant cross wind on both
the approaches and on the bridge itself. riding a normal 32 spoke
wheelset, my bike is somewhat squirrely when the wind is bad. riding 16
spoke wheels however, the effect of cross winds is substantially less.

OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels. I suppose that
my weight and preferred bike geometry (slack and stable) probably
minimize crosswind-related steering anomalies.

Chalo Colina

jim beam wrote:

well, there's one huge advantage of low spoke count wheels - that of
wind resistance.
snip
it's almost always subject to significant cross wind on both
the approaches and on the bridge itself. riding a normal 32 spoke
wheelset, my bike is somewhat squirrely when the wind is bad. riding 16
spoke wheels however, the effect of cross winds is substantially less.

OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels. I suppose that
my weight and preferred bike geometry (slack and stable) probably
minimize crosswind-related steering anomalies.

Chalo Colina

Chalo wrote:
jim beam wrote:
it's almost always subject to significant cross wind on both
the approaches and on the bridge itself. riding a normal 32 spoke
wheelset, my bike is somewhat squirrely when the wind is bad. riding 16
spoke wheels however, the effect of cross winds is substantially less.
OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels.

It's obvious nonsense, too; how do you suppose sock-boy imagines tandem
captains manage, with 48 spoke wheels and an extra rider stuck out the
back?

[Even if it's only the front wheel - and if then, why run a 16 spoke rear
wheel, hmmm? - a bike with front panniers on would be unmanageable if this
idea was correct.]
--
David Damerell Distortion Field!

Chalo wrote:
jim beam wrote:
it's almost always subject to significant cross wind on both
the approaches and on the bridge itself. riding a normal 32 spoke
wheelset, my bike is somewhat squirrely when the wind is bad. riding 16
spoke wheels however, the effect of cross winds is substantially less.
OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels.

It's obvious nonsense, too; how do you suppose sock-boy imagines tandem
captains manage, with 48 spoke wheels and an extra rider stuck out the
back?

[Even if it's only the front wheel - and if then, why run a 16 spoke rear
wheel, hmmm? - a bike with front panniers on would be unmanageable if this
idea was correct.]
--
David Damerell Distortion Field!

On 19 Oct 2004 11:12:54 +0100 (BST), David Damerell
wrote:

Chalo wrote:
jim beam wrote:
it's almost always subject to significant cross wind on both
the approaches and on the bridge itself. riding a normal 32 spoke
wheelset, my bike is somewhat squirrely when the wind is bad. riding 16
spoke wheels however, the effect of cross winds is substantially less.
OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels.

It's obvious nonsense, too; how do you suppose sock-boy imagines tandem
captains manage, with 48 spoke wheels and an extra rider stuck out the
back?

[Even if it's only the front wheel - and if then, why run a 16 spoke rear
wheel, hmmm? - a bike with front panniers on would be unmanageable if this
idea was correct.]

Dear David,

Perhaps "Dangerous Crosswind" road signs aren't as common in
your neck of the woods?

On this side of the Atlantic, high wind warnings sometimes
close the interstate highway heading south from Pueblo to
New Mexico--usually after a few trucks blow over.

Up on bridges like the Golden Gate, the winds are usually
worse.

And there's always this example of a what a wind can do:

http://www.nwrain.com/~newtsuit/reco...narrows/gg.htm

That's just a 35 to 45 mph crosswind, not terribly unusual
for that bridge and area.

Carl Fogel

On 19 Oct 2004 11:12:54 +0100 (BST), David Damerell
wrote:

Chalo wrote:
jim beam wrote:
it's almost always subject to significant cross wind on both
the approaches and on the bridge itself. riding a normal 32 spoke
wheelset, my bike is somewhat squirrely when the wind is bad. riding 16
spoke wheels however, the effect of cross winds is substantially less.
OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels.

It's obvious nonsense, too; how do you suppose sock-boy imagines tandem
captains manage, with 48 spoke wheels and an extra rider stuck out the
back?

[Even if it's only the front wheel - and if then, why run a 16 spoke rear
wheel, hmmm? - a bike with front panniers on would be unmanageable if this
idea was correct.]

Dear David,

Perhaps "Dangerous Crosswind" road signs aren't as common in
your neck of the woods?

On this side of the Atlantic, high wind warnings sometimes
close the interstate highway heading south from Pueblo to
New Mexico--usually after a few trucks blow over.

Up on bridges like the Golden Gate, the winds are usually
worse.

And there's always this example of a what a wind can do:

http://www.nwrain.com/~newtsuit/reco...narrows/gg.htm

That's just a 35 to 45 mph crosswind, not terribly unusual
for that bridge and area.

Carl Fogel

David Damerell wrote:

Chalo wrote:

jim beam wrote:

riding 16
spoke wheels however, the effect of cross winds is substantially less.

OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels.

It's obvious nonsense, too; how do you suppose sock-boy imagines tandem
captains manage, with 48 spoke wheels and an extra rider stuck out the
back?

To extend "jim beam" the benefit of the doubt, I'll point out that a
tandem captain's situation is more like my own, with a heavily loaded
front wheel that is unlikely to be pushed around by wind due to its
sizeable contact patch. It's obvious if you ride one that a tandem
requires more force at the bars than a single bike, especially a
twitchy single.

[Even if it's only the front wheel - and if then, why run a 16 spoke rear
wheel, hmmm? - a bike with front panniers on would be unmanageable if this
idea was correct.]

A bike with empty and lightweight front panniers would likely be
unmanageable in heavy crosswinds if jim beam's assertion is correct,
and for all I know it might be. A bike with loaded front panniers
would probably have enough inertia in its front end to render a
comparison inconclusive.

Since I have no applicable experience by which to judge jim beam's
assertion, I am inclined to take him at his word, in the absence of
other relevant evidence. I have insufficient data to just assume he's
wrong.

If he's correct, I still don't think that makes a compelling argument
for the general use of 16-spoke wheels. But at least there would be
some functional quality for which he has traded off all the advantages
of conventional wheels.

Chalo Colina

David Damerell wrote:

Chalo wrote:

jim beam wrote:

riding 16
spoke wheels however, the effect of cross winds is substantially less.

OK, that's an issue I had not considered. The effects of crosswinds
are not noticeable to me, even with 48 spoke wheels.

It's obvious nonsense, too; how do you suppose sock-boy imagines tandem
captains manage, with 48 spoke wheels and an extra rider stuck out the
back?

To extend "jim beam" the benefit of the doubt, I'll point out that a
tandem captain's situation is more like my own, with a heavily loaded
front wheel that is unlikely to be pushed around by wind due to its
sizeable contact patch. It's obvious if you ride one that a tandem
requires more force at the bars than a single bike, especially a
twitchy single.

[Even if it's only the front wheel - and if then, why run a 16 spoke rear
wheel, hmmm? - a bike with front panniers on would be unmanageable if this
idea was correct.]

A bike with empty and lightweight front panniers would likely be
unmanageable in heavy crosswinds if jim beam's assertion is correct,
and for all I know it might be. A bike with loaded front panniers
would probably have enough inertia in its front end to render a
comparison inconclusive.

Since I have no applicable experience by which to judge jim beam's
assertion, I am inclined to take him at his word, in the absence of
other relevant evidence. I have insufficient data to just assume he's
wrong.

If he's correct, I still don't think that makes a compelling argument
for the general use of 16-spoke wheels. But at least there would be
some functional quality for which he has traded off all the advantages
of conventional wheels.

Chalo Colina

Chalo Colina writes:

Riding a normal 32 spoke wheelset, my bike is somewhat squirrely
when the wind is bad. Riding 16 spoke wheels however, the effect
of cross winds is substantially less.

OK, that's an issue I had not considered. The effects of
crosswinds are not noticeable to me, even with 48 spoke wheels.

It's obvious nonsense, too; how do you suppose sock-boy imagines
tandem captains manage, with 48 spoke wheels and an extra rider
stuck out the back?

To extend "jim beam" the benefit of the doubt, I'll point out that a
tandem captain's situation is more like my own, with a heavily
loaded front wheel that is unlikely to be pushed around by wind due
to its sizeable contact patch. It's obvious if you ride one that a
tandem requires more force at the bars than a single bike,
especially a twitchy single.

Crosswinds do not make wheels skid sideways, but rather they induce
steering movements while causing the rider to lean sideways as if
cornering. In gusty winds this makes riding a reasonably straight
path impossible and can blow the rider into the adjacent lane (or off
the road). It's a lot like riding next to someone pushing on one's
shoulder while shoving the handlebar forward. Both of these effects
have little to do with number of spokes, mainly arising from the
longitudinal cross section of the wheel and that of the rider.

[Even if it's only the front wheel - and if then, why run a 16
spoke rear wheel, hmmm? - a bike with front panniers on would be
unmanageable if this idea was correct.]

A bike with empty and lightweight front panniers would likely be
unmanageable in heavy crosswinds if jim beam's assertion is correct,
and for all I know it might be. A bike with loaded front panniers
would probably have enough inertia in its front end to render a
comparison inconclusive.

Weight on the wheel has no effect. It is mainly the effect of wind
steering the front end. Rear wheels have no effect on steering
although total cross section of bicycle and rider exposed to a lateral
wind affects lean. One effect steers the bicycle off course and the
other requires the rider lean into the wind or fall over.

Since I have no applicable experience by which to judge jim beam's
assertion, I am inclined to take him at his word, in the absence of
other relevant evidence. I have insufficient data to just assume he's
wrong.

The claim is probably less accurate that it may first appear because
rim depth is the principal contributor to side wind sensitivity. Disc
wheels don't work at all in cross winds of any significant for this
reason. Sixteen spoke wheels generally have deeper rim cross sections
than thirty two spoke wheels and produce a greater steering effect.
Spoke count is insignificant because the steering effect in a 15mph
wind is like the spoke drag effect riding forward at 15-20mph in still
air, where I'm sure you can't detect the difference between 16 and 32
spokes without a stop watch.

If he's correct, I still don't think that makes a compelling argument
for the general use of 16-spoke wheels. But at least there would be
some functional quality for which he has traded off all the advantages
of conventional wheels.

I see no advantage other than TT racing in still or nearly still air.

Jobst Brandt