Tire-making: bead stress, tire width, math, woe........

On Aug 25, 5:51*pm, john B. wrote:

You can spout all the rhetoric you wish, unfortunately it doesn't
prove anything. given that my point is essentially that for whatever
reason nobody is making tires without bead reinforcement. All you need
to "win" is to point out at a bicycle tire which doesn't include a
form of bead reinforcement.

So what do I win?

http://www.google.com/patents?id=bnh...page&q&f=false

DR

DirtRoadie wrote:
On Aug 25, 5:51 pm, john wrote:

You can spout all the rhetoric you wish, unfortunately it doesn't
prove anything. given that my point is essentially that for whatever
reason nobody is making tires without bead reinforcement. All you need
to "win" is to point out at a bicycle tire which doesn't include a
form of bead reinforcement.

So what do I win?

http://www.google.com/patents?id=bnh...page&q&f=false


"Doesn't" =/= "Didn't"


--
- Frank Krygowski

john B. wrote:


I'll repeat the question one more time - if your assertion that the
reinforced bead is unnecessary is correct why aren't tire
manufacturers making tires without it.

Is there a possibility that tire manufacturers have liability fears?
There are plenty of non-hook-bead rims out there, and plenty of people
who have very little capacity for following instructions.

I can imagine tire manufacturers being terrified of having a 12-year-old
boy (or an adult who's no smarter) put an unreinforced tire onto a
non-hook-bead rim and blow it off on the first fast downhill.

People like that - or their parents - seem to be quite capable of
reading ads for personal injury lawyers, even if they can't read directions.


--
- Frank Krygowski

On Aug 26, 9:53*am, Frank Krygowski
wrote:
DirtRoadie wrote:
On Aug 25, 5:51 pm, john *wrote:

You can spout all the rhetoric you wish, unfortunately it doesn't
prove anything. given that my point is essentially that for whatever
reason nobody is making tires without bead reinforcement. All you need
to "win" is to point out at a bicycle tire which doesn't include a
form of bead reinforcement.

So what do I win?

http://www.google.com/patents?id=bnh...description&zo...

"Doesn't" =/= "Didn't"

--
- Frank Krygowski

Birds of a feather.
DR

Frank Krygowski wrote:
:john B. wrote:
:
:
: I'll repeat the question one more time - if your assertion that the
: reinforced bead is unnecessary is correct why aren't tire
: manufacturers making tires without it.

:Is there a possibility that tire manufacturers have liability fears?
:There are plenty of non-hook-bead rims out there, and plenty of people
:who have very little capacity for following instructions.

:I can imagine tire manufacturers being terrified of having a 12-year-old
:boy (or an adult who's no smarter) put an unreinforced tire onto a
:non-hook-bead rim and blow it off on the first fast downhill.

:People like that - or their parents - seem to be quite capable of
:reading ads for personal injury lawyers, even if they can't read directions.

Were there really a go-faster advantage, Someone would build a
non-standard wheel size, and sell no standard beadless tires.

They don't. Because having your tires come off, which they will
without a bead, is not a go-faster advantage: crashing slows the
**** out of you.


--
This is not a randomly numbered sig.

DirtRoadie wrote:
Speaking both conceptually and pragmatically, if
bead reinforcement is the ONLY necessary tire retaining element, why
are some some some rims "not suitable for Kevlar bead?"
http://www.google.com/url?sa=D&q=htt...t/WEINRIMS.JPG
(Thanks AM)

Keep in mind, that Weinmann graphic probably dates from about 1978.
Kevlar beads were new then. Weinmann couldn't be expected to recall and
melt down all its rims because of a new type of bead just coming on the
market.

There have been, and still are, rims that relied only on the bead
reinforcement to keep the tire in place. (I've still got Weinmann A-129s
on one bike.) And as mentioned, car tires still use only that
mechanism. Same for my motorcycle's tires.

What we need is a hero who will cut the kevlar or steel reinforcement
out of his front tire's bead, then inflate and ride over potholes,
bumps, fast downhills, etc. Then report back. If he can.

--
- Frank Krygowski

On Aug 26, 7:05*am, AMuzi wrote:


I believe a short perusal of tire and rim sections should
make the art clear except for willful disbelief.

One need not even look at ancient rims; a range of 1980s
products clearly shows the difference:

http://www.yellowjersey.org/photosfr...t/WEINRIMS.JPG

Ah, Weinmann 124, not suitable for kevlar bead. No-one told me. It
was not perfect, but I did manage to use Specialized Turbo S with
kevlar beads in these rims. They were the 25 marked tyres (more like
21mm). Had to degrease the rim and tyre with spirit and then they
held at least 105 psi without problem. I did take these tyres up to
115 psi which my body felt was their absolute limit. At 115 psi they
required continual checking to ensure the bead wire was not creeping
up. I forgot about the high pressure after some rides and the tube
would go BANG in the night. There was also a couple of incidents
while waiting in the road when the tyres were wet. This combination
would need glue to prevent the wet weather creep.
Later with the Super Champion Mixte rims I had no retention problems
bar the single incident (wet again) caused by an overlapping rim
tape.

-snip tire bead-

DirtRoadie wrote:
There is little point in trying, even when discussing concepts.
And you are the one bringing up "winning." I was trying to address
some interesting concepts brought to light by the OP's questions.

AMuzi wrote:
I believe a short perusal of tire and rim sections should
make the art clear except for willful disbelief.
One need not even look at ancient rims; a range of 1980s
products clearly shows the difference:
http://www.yellowjersey.org/photosfr...t/WEINRIMS.JPG

DirtRoadie wrote:
Thank you. That is instructive. My reason for seeking an "ancient"
example is a matter of curiosity, i.e. my wondering whether the
earliest rim/tire combinations, described as being "clamped on,"
relied upon an "external" form of bead reinforcement rather than the
modern wire/kevlar/carbon bead which is incorporated into the tire.

Can't readily find a link but peruse Sharp's Bicycles and
Tricycles for several variants.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

David Scheidt wrote:
Frank Krygowski wrote:
:john B. wrote:
:
:
: I'll repeat the question one more time - if your assertion that the
: reinforced bead is unnecessary is correct why aren't tire
: manufacturers making tires without it.

:Is there a possibility that tire manufacturers have liability fears?
:There are plenty of non-hook-bead rims out there, and plenty of people
:who have very little capacity for following instructions.

:I can imagine tire manufacturers being terrified of having a 12-year-old
:boy (or an adult who's no smarter) put an unreinforced tire onto a
:non-hook-bead rim and blow it off on the first fast downhill.

:People like that - or their parents - seem to be quite capable of
:reading ads for personal injury lawyers, even if they can't read directions.

Were there really a go-faster advantage, Someone would build a
non-standard wheel size, and sell no standard beadless tires.

They don't. Because having your tires come off, which they will
without a bead, is not a go-faster advantage: crashing slows the
**** out of you.


Good point regarding liability with straight side rims and
yes you're right that the non-beaded tires (most recent
which comes readily to mind are the Swiss Army bikes
1945~1994 version) use a unique diameter rim.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 8/26/2011 8:40 AM, DirtRoadie wrote:
On Aug 26, 12:05 am, wrote:

?!?!?!?
them's a lotta quotes
?!?!?!?


I believe a short perusal of tire and rim sections should
make the art clear except for willful disbelief.

One need not even look at ancient rims; a range of 1980s
products clearly shows the difference:

http://www.yellowjersey.org/photosfr...t/WEINRIMS.JPG


Thank you. That is instructive. My reason for seeking an "ancient"
example is a matter of curiosity, i.e. my wondering whether the
earliest rim/tire combinations, described as being "clamped on,"
relied upon an "external" form of bead reinforcement rather than the
modern wire/kevlar/carbon bead which is incorporated into the tire.

DR

Internal bead locks were used on racing tires from 1910~1930.
I don't recall seeing anything about external bead locks, but all kinds
of oddball stuff was tried. The patent application is probably out there
somewhere.

Here is a pic I stole from a Google Books book of a book:
http://www.norcom2000.com/users/dcim..._tire_lugs.png

-tiny-
http://tinyurl.com/3vlbmcv

The above is taken from a book from 1917; if you search Google Books for
the title "automobile tire handbook" it is the first result. There's
also some info in there about mixing straight-sided and hook-bead rims
of the era.

Even though tire CORDS back then were made of cotton***, extra retention
for normal vehicle tires generally wasn't necessary as the poor roads
and [lack of] vehicle suspension technology at the time prevented speeds
much beyond 20 MPH for any significant distance. The few primary streets
of cities would have been cobblestone or laid brick, and rural roads
were gravel (for main roads) or dirt (for most rural roads), both kept
well-rutted by horse-drawn carriage use.

The only vehicles that could achieve much in the way of speed were
racing vehicles on [wooden] racing tracks.



***(tires with cotton 'edge pieces' were called 'cord tires', as the fat
part of the casing edge was called the cord. The term "bead" only
referred to tires in which the steel wire was used, and the different
name was done purposely to easily differentiate a cotton-cord tire from
a steel-bead tire.

Wire beads were patented in 1901 by Goodyear, but cotton cord use
persisted for 20+ years due to poor metallurgy of the first steel-bead
tires and people with older wheels simply reluctant to switch to new
wheels.

....By the 1930's cotton-cord tires became impractical. Much of the USA
depression-era public works projects was building paved cross-country
roads, and average vehicle speeds increased to the point that the
cotton-cord tires were clearly less reliable than the steel beads. Also
by that time Goodyear's patent had expired, allowing other companies to
make steel bead tires also.)


------------


Obviously in the not-too-distant past, there were major bicycle rim
companies still producing non-hook-bead rims, and bicycle tires still
generally stayed put on the rims. Are any such rims still available new
today from "mainstream/Western" companies?

(what I mean by mainstream/Western is,,, I wouldn't count India
factories still turning out rod-brake bikes, but I would count Weinmann)