Crown race fit for Tange RDC-TRD cart. headset

New Tange-Seiki RDC-TRD 30.2 25.4 cartridge bearing headset for
threaded fork.

Before installing the crown race I tried to see that the bevel of the
crown race -- it is really a support for the inner bearing race --
matches the inner bevel of the Tange 4T5 - 3 bearing. It does not nest
in the same way that the top bearing cap fits into the inner bevel of
the top bearing. It seems too large.

Will the crown race change shape to fit after it is pressed onto the
fork, or was the wrong part packed in the box?

Harry Travis
Pine Barrens of NJ
USA

incredulous wrote:
New Tange-Seiki RDC-TRD 30.2 25.4 cartridge bearing headset for
threaded fork.

Before installing the crown race I tried to see that the bevel of the
crown race -- it is really a support for the inner bearing race --
matches the inner bevel of the Tange 4T5 - 3 bearing. It does not nest
in the same way that the top bearing cap fits into the inner bevel of
the top bearing. It seems too large.

Will the crown race change shape to fit after it is pressed onto the
fork, or was the wrong part packed in the box?

If it's steel, it won't change shape under normal installation.

On the Tange TechnoGlide BSC cartridge model, the steel
crown race is black. If you set the lower cup upside down on
a workbench, then set the crown race in it, less than 1mm
protrudes.

You are using a beveled-race adapter such as the Chris King
piece, right? Slamming a steel tube against the surface
isn't good practice. If your crown race is aluminum it will
deform and not mate well to the bearing.

Does that help?

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

On May 6, 11:29*pm, AMuzi wrote:
incredulous wrote:
New Tange-Seiki RDC-TRD 30.2 *25.4 cartridge bearing headset for
threaded fork.

Before installing the crown race I tried to see that the bevel of the
crown race -- it is really a support for the inner bearing race --
matches the inner bevel of the Tange 4T5 - 3 bearing. It does not nest
in the same way that the top bearing cap fits into the inner bevel of
the top bearing. It seems too large.

Will the crown race change shape to fit after it is pressed onto the
fork, or was the wrong part packed in the box?

If it's steel, it won't change shape under normal installation.

On the Tange TechnoGlide BSC cartridge model, the steel
crown race is black. If you set the lower cup upside down on
a workbench, then set the crown race in it, less than 1mm
protrudes.

You are using a beveled-race adapter such as the Chris King
piece, right? Slamming a steel tube against the surface
isn't good practice. If your crown race is aluminum it will
deform and not mate well to the bearing.

Does that help?

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

Not yet. I have already installed the lower and upper cups. When I
test fit the lower bearing up into the cup, a beveled outer outer race
of the sealed bearing matches the complementary interior beveled edge
of the the up. Just fits by hand, comes out by hand with a little
trouble, and feels good. Same as up top.

I expected the same fit on the black steel* crown race -- what is the
name for it, since it is not really a race?,-- not yet pressed onto
the fork. Instead, it is as though the circumference of the crown race
is bevel is larger than the interior bearing race bevel, so the loose
crown race can be canted. Another view of the fit is that it allows it
to be out of perfect parallel to the lower bearing while still being
in contact around the entire circumference of the inner bearing bevel.

Obviously, this is my first experience with a sealed bearing headset,
and maybe I am just discovering Tange's solution to lack of perfect
parallelism of the set fork-crown and the lower bearing cup. I could
see how a fork with the crown race tipped slight forward or backward
would operate just fine, with most of the balls in the bearing
carrying some of the load and handling unaffected.

*mildly magnetic

Harry Travis

incredulous wrote:
On May 6, 11:29 pm, AMuzi wrote:
incredulous wrote:
New Tange-Seiki RDC-TRD 30.2 25.4 cartridge bearing headset for
threaded fork.
Before installing the crown race I tried to see that the bevel of the
crown race -- it is really a support for the inner bearing race --
matches the inner bevel of the Tange 4T5 - 3 bearing. It does not nest
in the same way that the top bearing cap fits into the inner bevel of
the top bearing. It seems too large.
Will the crown race change shape to fit after it is pressed onto the
fork, or was the wrong part packed in the box?
If it's steel, it won't change shape under normal installation.

On the Tange TechnoGlide BSC cartridge model, the steel
crown race is black. If you set the lower cup upside down on
a workbench, then set the crown race in it, less than 1mm
protrudes.

You are using a beveled-race adapter such as the Chris King
piece, right? Slamming a steel tube against the surface
isn't good practice. If your crown race is aluminum it will
deform and not mate well to the bearing.

Does that help?

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

Not yet. I have already installed the lower and upper cups. When I
test fit the lower bearing up into the cup, a beveled outer outer race
of the sealed bearing matches the complementary interior beveled edge
of the the up. Just fits by hand, comes out by hand with a little
trouble, and feels good. Same as up top.

I expected the same fit on the black steel* crown race -- what is the
name for it, since it is not really a race?,-- not yet pressed onto
the fork. Instead, it is as though the circumference of the crown race
is bevel is larger than the interior bearing race bevel, so the loose
crown race can be canted. Another view of the fit is that it allows it
to be out of perfect parallel to the lower bearing while still being
in contact around the entire circumference of the inner bearing bevel.

Obviously, this is my first experience with a sealed bearing headset,
and maybe I am just discovering Tange's solution to lack of perfect
parallelism of the set fork-crown and the lower bearing cup. I could
see how a fork with the crown race tipped slight forward or backward
would operate just fine, with most of the balls in the bearing
carrying some of the load and handling unaffected.

*mildly magnetic

Oh, that's a feature, not a problem! (Jobst periodically
extols that virtue here) Works well in practice and it's
tolerant of some misalignment, much as Bianchi's 'floating
race' design of the 1960s but less complex.

p.s. Tange ships these in clear cylinders with a logo tape
seal. Highly unlikely anyone swapped a part without the open
package being obvious.

p.p.s. Yeah, I wrote 'crown race' because it seemed clear
enough if not quite correct. As you pointed out it's a
lower cartridge bearing conical seat or some such.

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