Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really needed? http://www.gemplers.com/docs/IS/123.pdf

"stryped" wrote in message
...
Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really needed? http://www.gemplers.com/docs/IS/123.pdf

I don't see a "centering pin" listed. Do you mean the guide pin of the lug
hole?

On Thu, 12 Feb 2009 14:17:57 -0800 (PST), stryped
wrote:

Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really needed? http://www.gemplers.com/docs/IS/123.pdf


Blink...blink...yes.

It keeps the tire from spinning


"If the personal freedoms guaranteed by the Constitution inhibit the government's ability to govern the people,
we should look to limit those guarantees."

Bill Clinton 1993-08-12

"stryped" wrote in message
...
Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really needed? http://www.gemplers.com/docs/IS/123.pdf

If you're talking about the pin that comes through the base, it is to keep
the tire from spinning during work. The old tire changers had a spinner
cone shaped device to keep it centered on the machine, and one pin to keep
it from spinning. Gawd, I wonder what the numerical equivalent was on that
threaded cone. One thread per two inches, or something like that.

Steve

stryped writes:

Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really needed?

Considering the many foot-pounds of torque you apply with the bead seating
tool, you need more than the spider to keep the wheel from spinning.

I wouldn't be too optimistic about these gadgets on any tires car sized and
up, unless you're desperate. The do-it-yourself savings are not worth the
effort, and they don't work very well. There's a reason tire changers are
big hydraulic tools costing $1000s.

Have you considered looking for a used tire changer? I bought a used
Coates 20-20 in 1979 for $120 and it has been working fine ever since.
This model is a serious air-powered machine. The only thing it lacks is
the extra pressure tank and ring under the tire that "blows" the bead
into place, but that's easy to get around anyway.

There must be plenty of them around, since the technology is always
advancing. When I bought mine, the 30-30 and (I think)40-40 had already
been around for a while.

Pete Stanaitis
--------------

stryped wrote:
Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really needed? http://www.gemplers.com/docs/IS/123.pdf

On Feb 13, 6:23*am, spaco wrote:
Have you considered looking for a used tire changer? * I bought a used
Coates 20-20 in 1979 for $120 and it has been working fine ever since.
This model is a serious air-powered machine. *The only thing it lacks is
the extra pressure tank and ring under the tire that "blows" the bead
into place, but that's easy to get around anyway.

There must be plenty of them around, since the technology is always
advancing. *When I bought mine, the 30-30 and (I think)40-40 had already
been around for a while.

Pete Stanaitis
--------------



stryped wrote:
Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really needed?http://www.gemplers.com/docs/IS/123.pdf- Hide quoted text -

- Show quoted text -

I have been looking. Actually, I had been thinking of making one of
these at home as I have some round and square tubing. Mainly for my 15
inch trailer wheels but alos, lawn mower, tiller, etc. It seemed like
a neat project.

But there is a "spider" that goes over the wheel and a top post that
screws down against the spider. I thought that this woudl hold the
tire?

If you were making one, how would you install a guide pin? Arent
different wheel's holes different spaces from center? I dont see how
one would work for all?

"stryped" wrote in message
...
On Feb 13, 6:23 am, spaco wrote:
Have you considered looking for a used tire changer? I bought a used
Coates 20-20 in 1979 for $120 and it has been working fine ever since.
This model is a serious air-powered machine. The only thing it lacks is
the extra pressure tank and ring under the tire that "blows" the bead
into place, but that's easy to get around anyway.

There must be plenty of them around, since the technology is always
advancing. When I bought mine, the 30-30 and (I think)40-40 had already
been around for a while.

Pete Stanaitis
--------------



stryped wrote:
Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really
needed?http://www.gemplers.com/docs/IS/123.pdf- Hide quoted text -

- Show quoted text -

I have been looking. Actually, I had been thinking of making one of
these at home as I have some round and square tubing. Mainly for my 15
inch trailer wheels but alos, lawn mower, tiller, etc. It seemed like
a neat project.

But there is a "spider" that goes over the wheel and a top post that
screws down against the spider. I thought that this woudl hold the
tire?

If you were making one, how would you install a guide pin? Arent
different wheel's holes different spaces from center? I dont see how
one would work for all?
The guide pin is mounted on a pivot so that it can swivel radially toward or
away from the post. Some also telescope to accomodate different rim widths.
The wheel has to be securely restrained from turning as sometimes it can
take quite a bit of force to get the tire bead to slide over the rim. If the
tire is soft and WELL lubricated it often goes very easily but some are a
real bear. The rim design effects the effort also.

Don Young

On Feb 13, 8:37*pm, "Don Young" wrote:
"stryped" wrote in message

...
On Feb 13, 6:23 am, spaco wrote:





Have you considered looking for a used tire changer? I bought a used
Coates 20-20 in 1979 for $120 and it has been working fine ever since.
This model is a serious air-powered machine. The only thing it lacks is
the extra pressure tank and ring under the tire that "blows" the bead
into place, but that's easy to get around anyway.

There must be plenty of them around, since the technology is always
advancing. When I bought mine, the 30-30 and (I think)40-40 had already
been around for a while.

Pete Stanaitis
--------------

stryped wrote:
Been looking at designs of manual tire changers. What is the purpose
of the "centering pin"? If the wheel is tightned down with the spider
and top post, is it really
needed?http://www.gemplers.com/docs/IS/123.pdf-Hide quoted text -

- Show quoted text -

I have been looking. Actually, I had been thinking of making one of
these at home as I have some round and square tubing. Mainly for my 15
inch trailer wheels but alos, lawn mower, tiller, etc. It seemed like
a neat project.

But there is a "spider" that goes over the wheel and a top post that
screws down against the spider. I thought that this woudl hold the
tire?

If you were making one, how would you install a guide pin? Arent
different wheel's holes different spaces from center? I dont see how
one would work for all?
The guide pin is mounted on a pivot so that it can swivel radially toward or
away from the post. Some also telescope to accomodate different rim widths.
The wheel has to be securely restrained from turning as sometimes it can
take quite a bit of force to get the tire bead to slide over the rim. If the
tire is soft and WELL lubricated it often goes very easily but some are a
real bear. The rim design effects the effort also.

Don Young- Hide quoted text -

- Show quoted text -

One last thing. I went to Harbor freight and looked at theirs. The
part the wheel "rests" on is a small circular piece of metal. Would
there be an advantage/disadvantage to having a larger piece, maybe a 1
foot by one foot square or so? It seems it would make the unit
stronger. Also would one of these changers work on the front tires of
my 8n? I have never had them off but I think the "center hole" of the
tire looks different.

As always appreciate your help!

On Mon, 16 Feb 2009 05:32:29 -0800 (PST), stryped
wrote:


If you were making one, how would you install a guide pin? Arent
different wheel's holes different spaces from center? I dont see how
one would work for all?
The guide pin is mounted on a pivot so that it can swivel radially toward or
away from the post. Some also telescope to accomodate different rim widths.
The wheel has to be securely restrained from turning as sometimes it can
take quite a bit of force to get the tire bead to slide over the rim. If the
tire is soft and WELL lubricated it often goes very easily but some are a
real bear. The rim design effects the effort also.

Don Young- Hide quoted text -

- Show quoted text -

One last thing. I went to Harbor freight and looked at theirs. The
part the wheel "rests" on is a small circular piece of metal. Would
there be an advantage/disadvantage to having a larger piece, maybe a 1
foot by one foot square or so? It seems it would make the unit
stronger. Also would one of these changers work on the front tires of
my 8n? I have never had them off but I think the "center hole" of the
tire looks different.

As always appreciate your help!


Some people simply feel obligated to keep reinventing the wheel.

All the power to them. On the other hand..they dont have a lot of time
to do other more important stuff because of this.

Gunner

"Upon Roosevelt's death in 1945, H. L. Mencken predicted in his diary
that Roosevelt would be remembered as a great president, "maybe even
alongside Washington and Lincoln," opining that Roosevelt "had every
quality that morons esteem in their heroes.""