Wheel building questions

Wrote:
On Thu, 14 Oct 2004 20:37:47 -0700, jim beam
wrote:

wrote:
snip

Dear Ron,

I think that the usual problem of claims about "feel" is
hard to overcome. No matter how resonant the structure of
the metal spokes, hub, and rim may be, it's all damped by
the inflated rubber tire.

if i flick a highly inflated tire with my finger, and the whole wheel
rings like a bell, has the shock of that minor impact been all dampe
by
the rubber or has it been transmitted to the wheels structure?


But you could be right. A faintly similar test would be to
try to tell the difference between hitting a tire while
blindfolded with the same hammer heads mounted on different
rubber-covered shafts--wood, fiberglass, and steel. I know
that carpenters believe in differences between the feel of
such materials, but I don't know about whether they would
claim to feel the difference with a resilient rubber tire on
one end and a rubber grip on the other.

Carl Fogel

Dear Jim,

I instantly assumed that you were insane, began scribbling a
reply that would expose your evil claims as the work of the
devil, and then remembered that I have a bicycle sitting in
the garage--a bicycle that I trust to back me up faithfully
whenever questions are raised.

I flicked a confident fingernail against the rear tire as my
bicycle slept peacefully on its back, wheels in the air. It
produced a dull, satisfying thunk, indicating that Jim Beam
is deluded. I flicked it several more times to confirm that
it was about as bell-like as a rubber ducky.

But then I grew over-confident and flicked my fingernail
against the front tire. Same tire model, same rim, 36
spokes, roughly the same tension, same inflation--and a
faint but undeniably bell-like vibration was painfully
evident.

The traitorous bicycle was rudely flipped right side up and
both tires were mercilessly flicked with a standard
fingernail. I leaned on the handlebars and on the seat. I
rolled it back and forth. But things remained stubbornly the
same. The rear tire sounded like someone kicking a car tire.
The front tire still gave a faint vibration.

Maybe the chain and gear cluster and freehub mechanism
deaden things on the rear wheel? Or the rigid triangle damps
things better than the fork? I checked that the brake pads
weren't binding.

I loosened both quick-releases. Same thing--front rings,
back doesn't.

I pulled the rear wheel out of the rigid frame and free from
the chain and began flicking it cruelly with my fingernail,
trying to make it cry as it stood helpless and alone on the
garage floor. It still emitted nothing more than a dull
thunk.

So maybe the weight of just the gears and freehub is enough
to deaden the vibration?

Or just the damping of a plastic spoke protector?

If you're familiar with violins, you know how tiny and yet
effective a wooden, rubber, or plastic mute is when pressed
against or clipped onto the bridge:

http://www.sharmusic.com/itemdy00Vio...=1304+GLD&Cat=

I hope that others will take a few moments and flick their
front and rear tires in the back of the head with a
fingernail--they can't fight back, so you can bully them as
much as you like.

Whether slight differences in such faint vibration can be
noticed while rolling along on the pavement is another
matter, but I want to know why my front wheel aspires to
Stradivarian heights, while my rear wheel seems to have a
cold.

Carl Fogel

Dear Carl and others,

I have tyred this test just now. The same thing happened to me, my bac
wheel rang less than the front wheel (I would not say it was a thud ..
it seemed like a long thud (i.e. it had a very slight ring to it))
This was on my road bike with the bent axle trued to compensate for th
bend (This is the wheel I will be replacing). This wheel has no plastic
guard on it, x 3 strait gage spokes. Why does my front wheel ring more
than my back?

Pete


--
big Pete

On Sun, 17 Oct 2004 04:47:03 +1000, big Pete
wrote:


Wrote:
On Thu, 14 Oct 2004 20:37:47 -0700, jim beam
wrote:

wrote:
snip

Dear Ron,

I think that the usual problem of claims about "feel" is
hard to overcome. No matter how resonant the structure of
the metal spokes, hub, and rim may be, it's all damped by
the inflated rubber tire.

if i flick a highly inflated tire with my finger, and the whole wheel
rings like a bell, has the shock of that minor impact been all damped
by
the rubber or has it been transmitted to the wheels structure?


But you could be right. A faintly similar test would be to
try to tell the difference between hitting a tire while
blindfolded with the same hammer heads mounted on different
rubber-covered shafts--wood, fiberglass, and steel. I know
that carpenters believe in differences between the feel of
such materials, but I don't know about whether they would
claim to feel the difference with a resilient rubber tire on
one end and a rubber grip on the other.

Carl Fogel

Dear Jim,

I instantly assumed that you were insane, began scribbling a
reply that would expose your evil claims as the work of the
devil, and then remembered that I have a bicycle sitting in
the garage--a bicycle that I trust to back me up faithfully
whenever questions are raised.

I flicked a confident fingernail against the rear tire as my
bicycle slept peacefully on its back, wheels in the air. It
produced a dull, satisfying thunk, indicating that Jim Beam
is deluded. I flicked it several more times to confirm that
it was about as bell-like as a rubber ducky.

But then I grew over-confident and flicked my fingernail
against the front tire. Same tire model, same rim, 36
spokes, roughly the same tension, same inflation--and a
faint but undeniably bell-like vibration was painfully
evident.

The traitorous bicycle was rudely flipped right side up and
both tires were mercilessly flicked with a standard
fingernail. I leaned on the handlebars and on the seat. I
rolled it back and forth. But things remained stubbornly the
same. The rear tire sounded like someone kicking a car tire.
The front tire still gave a faint vibration.

Maybe the chain and gear cluster and freehub mechanism
deaden things on the rear wheel? Or the rigid triangle damps
things better than the fork? I checked that the brake pads
weren't binding.

I loosened both quick-releases. Same thing--front rings,
back doesn't.

I pulled the rear wheel out of the rigid frame and free from
the chain and began flicking it cruelly with my fingernail,
trying to make it cry as it stood helpless and alone on the
garage floor. It still emitted nothing more than a dull
thunk.

So maybe the weight of just the gears and freehub is enough
to deaden the vibration?

Or just the damping of a plastic spoke protector?

If you're familiar with violins, you know how tiny and yet
effective a wooden, rubber, or plastic mute is when pressed
against or clipped onto the bridge:

http://www.sharmusic.com/itemdy00Vio...=1304+GLD&Cat=

I hope that others will take a few moments and flick their
front and rear tires in the back of the head with a
fingernail--they can't fight back, so you can bully them as
much as you like.

Whether slight differences in such faint vibration can be
noticed while rolling along on the pavement is another
matter, but I want to know why my front wheel aspires to
Stradivarian heights, while my rear wheel seems to have a
cold.

Carl Fogel

Dear Carl and others,

I have tyred this test just now. The same thing happened to me, my back
wheel rang less than the front wheel (I would not say it was a thud ...
it seemed like a long thud (i.e. it had a very slight ring to it)).
This was on my road bike with the bent axle trued to compensate for the
bend (This is the wheel I will be replacing). This wheel has no plastic
guard on it, x 3 strait gage spokes. Why does my front wheel ring more
than my back?

Pete

Dear Pete,

Since your rear wheel lacks a plastic spoke guard, the most
likely suspect in the deadening of the rear wheel versus the
front when the tire is flicked with a fingernail is the
extra mass of the gear cluster and the hub mechanism

Carl Fogel

On Sun, 17 Oct 2004 04:47:03 +1000, big Pete
wrote:


Wrote:
On Thu, 14 Oct 2004 20:37:47 -0700, jim beam
wrote:

wrote:
snip

Dear Ron,

I think that the usual problem of claims about "feel" is
hard to overcome. No matter how resonant the structure of
the metal spokes, hub, and rim may be, it's all damped by
the inflated rubber tire.

if i flick a highly inflated tire with my finger, and the whole wheel
rings like a bell, has the shock of that minor impact been all damped
by
the rubber or has it been transmitted to the wheels structure?


But you could be right. A faintly similar test would be to
try to tell the difference between hitting a tire while
blindfolded with the same hammer heads mounted on different
rubber-covered shafts--wood, fiberglass, and steel. I know
that carpenters believe in differences between the feel of
such materials, but I don't know about whether they would
claim to feel the difference with a resilient rubber tire on
one end and a rubber grip on the other.

Carl Fogel

Dear Jim,

I instantly assumed that you were insane, began scribbling a
reply that would expose your evil claims as the work of the
devil, and then remembered that I have a bicycle sitting in
the garage--a bicycle that I trust to back me up faithfully
whenever questions are raised.

I flicked a confident fingernail against the rear tire as my
bicycle slept peacefully on its back, wheels in the air. It
produced a dull, satisfying thunk, indicating that Jim Beam
is deluded. I flicked it several more times to confirm that
it was about as bell-like as a rubber ducky.

But then I grew over-confident and flicked my fingernail
against the front tire. Same tire model, same rim, 36
spokes, roughly the same tension, same inflation--and a
faint but undeniably bell-like vibration was painfully
evident.

The traitorous bicycle was rudely flipped right side up and
both tires were mercilessly flicked with a standard
fingernail. I leaned on the handlebars and on the seat. I
rolled it back and forth. But things remained stubbornly the
same. The rear tire sounded like someone kicking a car tire.
The front tire still gave a faint vibration.

Maybe the chain and gear cluster and freehub mechanism
deaden things on the rear wheel? Or the rigid triangle damps
things better than the fork? I checked that the brake pads
weren't binding.

I loosened both quick-releases. Same thing--front rings,
back doesn't.

I pulled the rear wheel out of the rigid frame and free from
the chain and began flicking it cruelly with my fingernail,
trying to make it cry as it stood helpless and alone on the
garage floor. It still emitted nothing more than a dull
thunk.

So maybe the weight of just the gears and freehub is enough
to deaden the vibration?

Or just the damping of a plastic spoke protector?

If you're familiar with violins, you know how tiny and yet
effective a wooden, rubber, or plastic mute is when pressed
against or clipped onto the bridge:

http://www.sharmusic.com/itemdy00Vio...=1304+GLD&Cat=

I hope that others will take a few moments and flick their
front and rear tires in the back of the head with a
fingernail--they can't fight back, so you can bully them as
much as you like.

Whether slight differences in such faint vibration can be
noticed while rolling along on the pavement is another
matter, but I want to know why my front wheel aspires to
Stradivarian heights, while my rear wheel seems to have a
cold.

Carl Fogel

Dear Carl and others,

I have tyred this test just now. The same thing happened to me, my back
wheel rang less than the front wheel (I would not say it was a thud ...
it seemed like a long thud (i.e. it had a very slight ring to it)).
This was on my road bike with the bent axle trued to compensate for the
bend (This is the wheel I will be replacing). This wheel has no plastic
guard on it, x 3 strait gage spokes. Why does my front wheel ring more
than my back?

Pete

Dear Pete,

Since your rear wheel lacks a plastic spoke guard, the most
likely suspect in the deadening of the rear wheel versus the
front when the tire is flicked with a fingernail is the
extra mass of the gear cluster and the hub mechanism

Carl Fogel