integrated headset -- how to choose fork?

On Mon, 19 Dec 2005 01:39:29 +0100, geos <[email hidden]>

Quoted message said:

Hello everyone,

Probably this is easy for people with experience but I couldn't find any
answer.

The situation is as follows: I have an integrated headset, cane creek
type, 41.2mm bearings diameter, 45mm frame headtube outer diameter.

If you plan to keep this bike for a long time, buy your headset spares
now. You may need them in a few years. This type of headset is, for
the most part, not standardized, and it is unlikely that the alternate
replacement parts makers will offer any spares for these units as a
result.

Quoted message said:

What should be the diameter of the fork's crown (some call it
"shoulder", it's the place where bottom bearing rests and the steering
tube begins) for proper visual alignment and headset mounting? Should it
be exactly 45mm or bit less, like 44mm? Or maybe a bit more, like 47mm?

This is almost irrelevant; the diameter of the shoulder need only be
adequate for the crown race to seat against, and could be as small as
33 mm (not uncommon on older steel forks, and makes crown race
replacement much easier) or as large as 40mm or more (which makes
crown race replacment a more annoying task). There is no "visual
alignment" to worry about. By definition, the lower bearing *will*
center the steerer in the headtube if the assembly process is done
correctly, and the crown race cannot mount in any manner except
concentric to the tube as long as the tolerances are correct and the
race is fully seated against the properly-machined shoulder.

Quoted message said:

I would greatly appreciate your help, I have no experience with
integrated headsets.

Many of us would prefer to remain just as inexperienced, but not all
will have that opportunity. Integrated headsets are widely disparaged
for a variety of reasons; see the Chris King site for one explanation.

As for dimensional considerations, even with an integrated headset,
the steerer tube diameter for a bike that uses a 1 1/8" steerer is
still the same standard 30mm (usually plus just a bit to ensure an
interference fit; Chris King lists it as 30.1mm) as it is for any
other type of 1 1/8" headset. The diameter of the shoulder on the
fork will be whatever the fork's manufacturer decided to make it.
--
Typoes are a feature, not a bug.
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Werehatrack said:

On Mon, 19 Dec 2005 01:39:29 +0100, geos <[email hidden]>

Quoted message said:

What should be the diameter of the fork's crown (some call it
"shoulder", it's the place where bottom bearing rests and the steering
tube begins) for proper visual alignment and headset mounting? Should it
be exactly 45mm or bit less, like 44mm? Or maybe a bit more, like 47mm?

This is almost irrelevant; the diameter of the shoulder need only be
adequate for the crown race to seat against, and could be as small as
33 mm (not uncommon on older steel forks, and makes crown race
replacement much easier) or as large as 40mm or more (which makes
crown race replacment a more annoying task). There is no "visual
alignment" to worry about. By definition, the lower bearing *will*
center the steerer in the headtube if the assembly process is done
correctly, and the crown race cannot mount in any manner except
concentric to the tube as long as the tolerances are correct and the
race is fully seated against the properly-machined shoulder.

Werehatrack, thanks for the answer. Perhaps I misexplained what I meant.
I know that the lower bearing will center the steerer. I wanted to ask
about the "visual alignment" when you look at the bike, like this:

http://www.flyte1.com/soar/janette/store/images/SRS3-bike_xl.jpg

The "transition" between the headset (lower bearing) and the fork's
shoulder is smooth, both have similar diameter, the headtube perfectly
matches the size of the headset and the fork's crown.

My question is that couple of time I saw headtubes with outer diameter
50mm and headsets that fit them also 50mm, but the fork's crown diameter
was 49mm. I am not experienced with forks but since I haven't seen any
fork with 50mm crown diameter I assumed that this is the way to go for
this size, ie. 50mm OD headtube, 50mm headset, 49mm fork.

Now I have headtube which outer diameter is 45mm. I also have the
headset that fits the headtube. But what should be the fork's crown
diameter? Should I look for 45mm or a bit less, 44mm (like Ritchey WCS)?

When I use 47/49mm fork's crown then it will stand out a bit (1 and 2mm
respectively) outside the headtube. When I use 45mm, the headtube will
match the fork perfectly. But I haven't seen any 45mm forks, only 44mm.

So, is it the way to go for this size, ie. 45mm OD headtube, 45mm
headset and 44mm fork? Could anybody familiar with this confirm/suggest
something more?

Quoted message said:

Quoted message said:

I would greatly appreciate your help, I have no experience with
integrated headsets.

Many of us would prefer to remain just as inexperienced, but not all
will have that opportunity. Integrated headsets are widely disparaged
for a variety of reasons; see the Chris King site for one explanation.

thanks, I read that article but after I'd bought the frame.

I would greatly appreciate your further suggestions/explanations if you
have such ones about this "visual alignment" type of visual alignment 🙂.

cheers,
geos

On Tue, 20 Dec 2005 00:46:15 +0100, geos <[email hidden]>

Quoted message said:

Perhaps I misexplained what I meant.
I know that the lower bearing will center the steerer. I wanted to ask
about the "visual alignment" when you look at the bike, like this:

http://www.flyte1.com/soar/janette/store/images/SRS3-bike_xl.jpg

The "transition" between the headset (lower bearing) and the fork's
shoulder is smooth, both have similar diameter, the headtube perfectly
matches the size of the headset and the fork's crown.

My question is that couple of time I saw headtubes with outer diameter
50mm and headsets that fit them also 50mm, but the fork's crown diameter
was 49mm. I am not experienced with forks but since I haven't seen any
fork with 50mm crown diameter I assumed that this is the way to go for
this size, ie. 50mm OD headtube, 50mm headset, 49mm fork.

Now I have headtube which outer diameter is 45mm. I also have the
headset that fits the headtube. But what should be the fork's crown
diameter? Should I look for 45mm or a bit less, 44mm (like Ritchey WCS)?

When I use 47/49mm fork's crown then it will stand out a bit (1 and 2mm
respectively) outside the headtube. When I use 45mm, the headtube will
match the fork perfectly. But I haven't seen any 45mm forks, only 44mm.

So, is it the way to go for this size, ie. 45mm OD headtube, 45mm
headset and 44mm fork? Could anybody familiar with this confirm/suggest
something more?

If I am reading your post correctly, I doubt very much that you are
going to find any fork maker that attempts, in any manner, to pay the
slightest bit of attention to what I perceive as this "flow of design
lines" type of issue. What you seem to be talking about is purely a
matter of aesthetics, and this is at best a tertiary consideration in
the aftermarket after weight, strength, materials-fashionability,
aerodynamics (on road bikes) and cost. A bike manufacturer *may*
attempt to sculpt the bits of a bike to make the design as visually
harmonious as you suggest on occasion, but the majority will attend to
the structural matters first and leave appearance considerations at
*this* level as an exercise to be contemplated only on their
ultra-high-end units (and specialty-market bikes like certain classes
of cruiser) if at all.

In short: from a purely functional standpoint, the issue has no
effect. Since the majority of serious bike builders and aftermarket
parts suppliers are much more concerned with function than form, this
is a detail that I don't think you're going to have a lot of luck
finding infromation about.

As for what you *should* use; the technical answer is "a fork
appropriate to achieve the correct geometry for the frame"; any other
consideration is a matter of opinion. To achieve what you seem to be
aiming for, I suspect your only avenues will be to have a custom fork
created by a specialty builder or to directly contact the various fork
manufacturers to see if they even have a published or known spec for
the dimension that you're concerned with. Don't be too surprised if
the majority act like they've never been asked this question
previously.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Werehatrack said:

If I am reading your post correctly, I doubt very much that you are
going to find any fork maker that attempts, in any manner, to pay the
slightest bit of attention to what I perceive as this "flow of design
lines" type of issue. What you seem to be talking about is purely a
matter of aesthetics, and this is at best a tertiary consideration in
the aftermarket after weight, strength, materials-fashionability,
aerodynamics (on road bikes) and cost. A bike manufacturer *may*
attempt to sculpt the bits of a bike to make the design as visually
harmonious as you suggest on occasion, but the majority will attend to
the structural matters first and leave appearance considerations at
*this* level as an exercise to be contemplated only on their
ultra-high-end units (and specialty-market bikes like certain classes
of cruiser) if at all.

Quoted message said:

In short: from a purely functional standpoint, the issue has no
effect. Since the majority of serious bike builders and aftermarket
parts suppliers are much more concerned with function than form, this
is a detail that I don't think you're going to have a lot of luck
finding infromation about.

No doubt about that, Werehatrack. thanks again for your opinion. of
course, it isn't the priority when looking for a fork, but as you say an
aesthetic issue which I concern. The problem is that after I made my
decision about the fork I visited a shop with a frame, and it happend
that the fork doesn't match the frame (using this thread's meaning of
visual alignment).

Is it a big issue? As you say, from the functional point of view
probably not (although I would think about riding in the rain with too
big fork's shoulder, when water can penetrate lower bearing). I also
haven't seen a bike with mismatched integrated headset-headtube join,
but probably they exists. Ritchey on his site says that his forks have
"44mm crown shoulder [which] aligns with integrated and standard
headsets for visual alignment".

Generally it seems to me that bike manufactures pay a bit of attention
to this aesthetic issue, at least they avoid using mismatched sizing
even they don't state this explicitly. Probably it is not an issue for
an average user who buys a bike and everything is all right. But when I
look at auctions on ebay, some mention that the reason for selling a
fork is that it doesn't fit the bike (which also may mean a steering
tube diameter mismatch, I don't know).

Anyway, I buy parts for my first road bike, and as an unexperienced
person I want to know everything I can 🙂 I thought that fork's crown
diameter was standarized. The lack of this dimension in
technical/marketing papers caused that I didn't pay much attention to
this issue. Hence my confusion when I went to the shop and saw the
misaligned fork.

thanks again
cheers,
geos