Bicycle Tire-Making: cable cozies for Christmas

Two matters to report on today:

First, there is now a real, actual website.
www.beevilletire.com

As I noted in another post, the local ISP I had dropped their
free/personal web space service and those pages are currently showing up
as 404. The beevilletire site is on a real hosting account now.

,,,,,

Second, the cable-thread-wrapping thingy is done and (mostly) working
correctly--or at least, what is wrong looks easy to fix:
http://beevilletire.com/early_attemp.../test_016.html

Still no actual tires made tho. Maybe by spring... It's too damn cold to
ride anyway right now.

On 12/19/2016 5:47 PM, DougC wrote:

,,,,,

Second, the cable-thread-wrapping thingy is done and (mostly) working
correctly--or at least, what is wrong looks easy to fix:
http://beevilletire.com/early_attemp.../test_016.html

Correction:
try
http://beevilletire.com/early_attemp...pdate_013.html

Re-arranged the website a bit.
I started out originally counting the casing attempts, but didn't post
pages for ones that totally failed. So the casing #'s skipped around and
I could see this was not an ideal narrative.

Now the site pages are just numbered by "update pages".

write a summary relating to the 13 updates ?

On 20/12/16 18:57, DougC wrote:
On 12/19/2016 5:47 PM, DougC wrote:

,,,,,

Second, the cable-thread-wrapping thingy is done and (mostly) working
correctly--or at least, what is wrong looks easy to fix:
http://beevilletire.com/early_attemp.../test_016.html

Correction:
try
http://beevilletire.com/early_attemp...pdate_013.html

Re-arranged the website a bit.
I started out originally counting the casing attempts, but didn't post
pages for ones that totally failed. So the casing #'s skipped around and
I could see this was not an ideal narrative.

Now the site pages are just numbered by "update pages".

That casing looks pretty good.

On Wed, 21 Dec 2016 13:55:35 -0600, DougC
wrote:
On 12/20/2016 5:22 PM, DATAKOLL MARINE RESEARCH wrote:
write a summary relating to the 13 updates ?

Points numbered to make arguing easier:

1) The goal here is to be able to make steel-belted radial bicycle
tires, since those will have the lowest rolling resistance of any
type.

Interesting, never having heard about Rinkowski or other radial bike
tires. Having followed your efforts off and on with what might be
described as mild befuddlement, I do have one question: why would
steel-belted radial bike tires have the lowest rolling resistance of any
type? Given that rolling resistance in bike tires is due to hysteresis
losses (except for those with rough or knobby tread, which adds
additional losses), why would adding the steel belt reduce hysteresis
and lower rolling resistance?

On 12/21/2016 2:11 PM, Tim McNamara wrote:
On Wed, 21 Dec 2016 13:55:35 -0600, DougC
wrote:
On 12/20/2016 5:22 PM, DATAKOLL MARINE RESEARCH wrote:
write a summary relating to the 13 updates ?

Points numbered to make arguing easier:

1) The goal here is to be able to make steel-belted radial bicycle
tires, since those will have the lowest rolling resistance of any
type.

Interesting, never having heard about Rinkowski or other radial bike
tires. Having followed your efforts off and on with what might be
described as mild befuddlement, I do have one question: why would
steel-belted radial bike tires have the lowest rolling resistance of any
type? Given that rolling resistance in bike tires is due to hysteresis
losses (except for those with rough or knobby tread, which adds
additional losses), why would adding the steel belt reduce hysteresis
and lower rolling resistance?


There is two reasons that (I believe) play a part.

1) One reason is that a tire that has a round cross-section when
inflated suffers from friction best described as tread squirm. Since the
outer diameter of the tire varies across the contact patch, some areas
of the tire are getting dragged slightly (forwards or backwards) as the
tire rolls along. They cannot all move at the same speed, since they do
not have the same circumference.

2) The other reason has to do with sidewall flex. If you place a
restrictive belt on a tire, it forces the contact patch to become
drastically wider and shorter than on a round-profile tire that was
inflated to the same pressure and carrying the same weight. This causes
shorter sidewall flex, and causes the tread area flex to be wider but to
a much lower angle. Hysteresis losses occur wherever the tire
casing/tread flexes. With a restrictive belt, the tire basically flexes
less-severely than a comparably-sized tire would without the belt.

Adding a restrictive belt to a tire decreases both these things.

J. Brandt insisted that in bicycle tires the cause of rolling resistance
was zero-percent of (#1) and 100% of (#2) above--but in the real world,
you don't get one effect without also getting the other. The effect of
tread squirm/friction may be rather small, but then again, compared to,
say, a car--the amount of /power/ used to move a bicycle is rather small
as well.



I have pondered an experiment using a method to possibly isolate these
two effects from each other, but I can't do it now. And it would result
in mere trivia I think. I may get around to it some day, there's still a
few sacred cows wandering loose.

On 12/21/2016 3:36 PM, DougC wrote:
more blathering

I've never really liked the way that various technical types like to
explain the matter of "tread flexing vs. sidewall flexing" because in a
normal bicycle tire, the tread and the sidewall are the same surface...
and the sidewalls are usually significantly thinner than the tread.

Some people like to go on about how critical it is to have "supple"
sidewalls and it is commonly presumed that racing bicycle tires are
generally skinwalls (even MTB tires!) but it may be that having thicker
sidewalls isn't the cause of a whole lot of rolling resistance. It must
be SOME of it, but having thick protected sidewalls may not be all that
big of a performance drag.

Reviewers cannot isolate the effects of the tread area and sidewalls
separately, because they cannot obtain tires that have these variations
in tread and sidewalls--but are otherwise identical.

So they are just guessing.

On Wednesday, December 21, 2016 at 1:36:04 PM UTC-8, Doug Cimperman wrote:
On 12/21/2016 2:11 PM, Tim McNamara wrote:
On Wed, 21 Dec 2016 13:55:35 -0600, DougC
wrote:
On 12/20/2016 5:22 PM, DATAKOLL MARINE RESEARCH wrote:
write a summary relating to the 13 updates ?

Points numbered to make arguing easier:

1) The goal here is to be able to make steel-belted radial bicycle
tires, since those will have the lowest rolling resistance of any
type.

Interesting, never having heard about Rinkowski or other radial bike
tires. Having followed your efforts off and on with what might be
described as mild befuddlement, I do have one question: why would
steel-belted radial bike tires have the lowest rolling resistance of any
type? Given that rolling resistance in bike tires is due to hysteresis
losses (except for those with rough or knobby tread, which adds
additional losses), why would adding the steel belt reduce hysteresis
and lower rolling resistance?


There is two reasons that (I believe) play a part.

1) One reason is that a tire that has a round cross-section when
inflated suffers from friction best described as tread squirm. Since the
outer diameter of the tire varies across the contact patch, some areas
of the tire are getting dragged slightly (forwards or backwards) as the
tire rolls along. They cannot all move at the same speed, since they do
not have the same circumference.

How can the circumference not be the same? I thot that rubber does not compress, but distorts.

On 12/21/2016 4:52 PM, DougC wrote:
On 12/21/2016 3:36 PM, DougC wrote:
more blathering

I've never really liked the way that various technical types like to
explain the matter of "tread flexing vs. sidewall flexing" because in a
normal bicycle tire, the tread and the sidewall are the same surface...
and the sidewalls are usually significantly thinner than the tread.

Some people like to go on about how critical it is to have "supple"
sidewalls and it is commonly presumed that racing bicycle tires are
generally skinwalls (even MTB tires!) but it may be that having thicker
sidewalls isn't the cause of a whole lot of rolling resistance. It must
be SOME of it, but having thick protected sidewalls may not be all that
big of a performance drag.

Reviewers cannot isolate the effects of the tread area and sidewalls
separately, because they cannot obtain tires that have these variations
in tread and sidewalls--but are otherwise identical.

So they are just guessing.

A few thoughts:

First, have you tried just modifying a stock tire by applying a belt?
It would involve removing the tread rubber then somehow applying a
substitute. But it might be much, much easier than developing an entire
tire manufacturing system, and might give preliminary data on whether
continuing the effort was worthwhile.

Second, I really wonder about the handling characteristics of a
squared-off cross section, which seems to be what you're attempting to
construct. (Correct me if I misunderstand that.) Bikes lean in turns,
and sudden changes in the shape and size of the contact patch sound
dicey to me. (I recall some '70s kid bikes with square "slick" rear
tires, but I never rode such a thing.)

Third, regarding your point above: I thought that some tires marketed
by Compass and by Rivendell had essentially the same core construction,
but with different sidewalls and treads. Am I wrong? If that's true,
you could use those to get some data on the effect of sidewall or tread
thickness.


--
- Frank Krygowski

On 12/21/2016 6:01 PM, Frank Krygowski wrote:

A few thoughts:

First, have you tried just modifying a stock tire by applying a belt? It
would involve removing the tread rubber then somehow applying a
substitute. But it might be much, much easier than developing an entire
tire manufacturing system, and might give preliminary data on whether
continuing the effort was worthwhile.


I've already got the tire part done tho? I could have been making
regular (bias-ply or radial!) tires already if I had wanted. This is
just a last detail of making the belts; I could not make any useful
belts until I could do this.

I considered at one point if there would be a way to convert existing
tires, and I don't think it would work well for several reasons.

Paul Rinkowski did produce some belted tires by winding wire over
tubular tires and then re-coating them with more rubber, but I suspect
that these tires were not very durable at all.

There was a fellow on one of the German bike forums who was trying to
use this method to make belted tires from cut-down 20" tubulars in 2012,
and no further news was ever posted of it. My guess is that it didn't
work well enough to be useful, since it would take a LOT less equipment
and time than what I've done.

Second, I really wonder about the handling characteristics of a
squared-off cross section, which seems to be what you're attempting to
construct. (Correct me if I misunderstand that.) Bikes lean in turns,
and sudden changes in the shape and size of the contact patch sound
dicey to me. (I recall some '70s kid bikes with square "slick" rear
tires, but I never rode such a thing.)


The cornering of a squared-off tire is gonna suck--but it will go faster
in straight lines, and people don't turn much anyway.

The kids' bike tire was the Schwinn Slik.
It did have a wide, flat slick tread.
And it was a rear tire, but sometimes we would put one on the front too.
It felt heavy on the front, but the main difference was that the
steering didn't center as well so you couldn't ride no-handed. I guess
that was due to the flatness more than the heaviness, but I don't really
know at this point. It was not /un/-stable however; it just made the
steering much more neutral.

The steel-belted radial tire is only really intended for Battle Mountain
IHPVA-style racing. -Or adventurous souls who want to sacrifice riding
comfort and extreme cornering ability to go a bit faster on the
straights. It may never become a "typical" bicycle tire in our lifetimes.

And people really /don't/ turn a lot, to be honest... Most casual riders
lean over less than 10 degrees when they turn. Very few lean more than
~20 degrees. People imagine themselves sweeping through corners at 45°
but it takes high speeds, very sticky tires and very clean pavement, and
even with the right circumstances most people are way to afraid to even
approach that.

Third, regarding your point above: I thought that some tires marketed
by Compass and by Rivendell had essentially the same core construction,
but with different sidewalls and treads. Am I wrong? If that's true,
you could use those to get some data on the effect of sidewall or tread
thickness.

Maybe--but that would only tell you about those Compass tires. It's
still difficult to quantify what's going on.

If you could make your own tires, then you could make test tires with
different features--say, a set of nine identical casings but with
different combinations of sidewalls and tread: sidewalls either 0mm, 1mm
or 2mm thick, and tread that is 2mm, 3mm, or 4mm thick.