threaded headset 'stack height' calculation

[[email protected]]

I need to buy a new 1" threaded headset for my winter bike but I am
being confronted with 'stack height' while trying to buy one... What
is it?

I have measured up the bike and I'm hoping someone can give me some
free advice:

1) From the top of the forks shoulder, where the bottom of the
existing headset bearing housing rests, to the bottom of the headtube
= 12.8mm

2) From the top of the headtube to the top of the forks thread, with
the existing headset locking ring removed, = 22.5mm

3) Therefore, is the stack height 12.8 + 22.5 = 35.3 ?????

Many thanks in advance for all your speedy replies - this is an
emergency as I haven't got my summer bike together yet either.

 

[A Muzi]

[email protected] wrote:
> I need to buy a new 1" threaded headset for my winter bike but I am
> being confronted with 'stack height' while trying to buy one... What
> is it?
>
> I have measured up the bike and I'm hoping someone can give me some
> free advice:
>
> 1) From the top of the forks shoulder, where the bottom of the
> existing headset bearing housing rests, to the bottom of the headtube
> = 12.8mm
>
> 2) From the top of the headtube to the top of the forks thread, with
> the existing headset locking ring removed, = 22.5mm
>
> 3) Therefore, is the stack height 12.8 + 22.5 = 35.3 ?????
>
> Many thanks in advance for all your speedy replies - this is an
> emergency as I haven't got my summer bike together yet either.

Right, or more simply, drop the fork itself through the head tube and
measure the portion sticking out the other end (i.e., head tube length
subtracted from column length).

Direct measure is always best!

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **

 

[[email protected]]

Many Thanks Andrew - any idea of the parameters involved..? If the
frame stack height is, say 35.3mm, a 34mm stack height headset is OK
or too small or a 36mm stack height headset is OK or too big?

 

[A Muzi]

[email protected] wrote:
> Many Thanks Andrew - any idea of the parameters involved..? If the
> frame stack height is, say 35.3mm, a 34mm stack height headset is OK
> or too small or a 36mm stack height headset is OK or too big?

You have a 2mm spacer which could be removed from a '36mm' headset and
certainly additional spacers may be added as needed.
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **

 

[A Muzi]

[email protected] wrote:
> Many Thanks Andrew - any idea of the parameters involved..? If the
> frame stack height is, say 35.3mm, a 34mm stack height headset is OK
> or too small or a 36mm stack height headset is OK or too big?

p.s. We cut threaded forks to 42mm, enough for a Super Record 4041, the
tallest common format. I recommend that length with spacers as needed
for a 'default' or standard length (for your future reference).
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **

 

[[email protected]]

ah, thanks raul..

recycling the old washer... heh.. great info

 

[[email protected]]

Yep, thanks Andrew

 

[Werehatrack]

On Sun, 11 May 2008 14:15:08 -0700 (PDT), "[email protected]"
<[email protected]> may have said:

>Many Thanks Andrew - any idea of the parameters involved..? If the
>frame stack height is, say 35.3mm, a 34mm stack height headset is OK
>or too small or a 36mm stack height headset is OK or too big?

In my experience, if the steerer projection is at or up to 2mm under
the stack height, the headset will fit as-is. If the steerer
projection is greater than the stack height, you may be able to take
up the space by recycling washers or spacers that are present in the
old headset, or the steerer can be shortened if absolutely necessary.
I have not had to do more than just fiddle with washers to get a 1"
threaded headset to fit in place of an existing threaded headset (when
not changing to a different fork) in any of the headsets that I've
replaced in the past two years. Admittedly, that's not a lot of
units, but threaded headsets seem much less variable than threadless,
and most of those that don't fit without modification seem to have a
slightly lower height, which is where adding a washer from the old one
becomes a useful tactic. Your mileage may vary, but the chances are
good that you will have no problem or can cope with the one that you
encounter.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

 

[Dan O]

On May 11, 3:35 pm, Werehatrack <[email protected]> wrote:
> On Sun, 11 May 2008 14:15:08 -0700 (PDT), "[email protected]"
> <[email protected]> may have said:
>
> >Many Thanks Andrew - any idea of the parameters involved..? If the
> >frame stack height is, say 35.3mm, a 34mm stack height headset is OK
> >or too small or a 36mm stack height headset is OK or too big?
>
> In my experience, if the steerer projection is at or up to 2mm under
> the stack height, the headset will fit as-is. If the steerer
> projection is greater than the stack height, you may be able to take
> up the space by recycling washers or spacers that are present in the
> old headset, or the steerer can be shortened if absolutely necessary.
> I have not had to do more than just fiddle with washers to get a 1"
> threaded headset to fit in place of an existing threaded headset (when
> not changing to a different fork) in any of the headsets that I've
> replaced in the past two years. Admittedly, that's not a lot of
> units, but threaded headsets seem much less variable than threadless,
> and most of those that don't fit without modification seem to have a
> slightly lower height, which is where adding a washer from the old one
> becomes a useful tactic. Your mileage may vary, but the chances are
> good that you will have no problem or can cope with the one that you
> encounter.
>

This is something that I guess I need to do, too. I noticed the Tange
headset was loose on my Myata 914. The locknut is a cap type nut,and
although a spacer was present, the cap / locknut wouldn't go down far
enough to hold the cone. Then I was looking at some pictures of a
similar bike, and noticed a bracket (absent from my bike) for mounting
a front reflector. which was effectively another spacer.

 

[[email protected]]

On May 11, 3:42 pm, "[email protected]" <[email protected]>
wrote:
> I need to buy a new 1" threaded headset for my winter bike but I am
> being confronted with 'stack height' while trying to buy one... What
> is it?
>
> I have measured up the bike and I'm hoping someone can give me some
> free advice:
>
> 1) From the top of the forks shoulder, where the bottom of the
> existing headset bearing housing rests, to the bottom of the headtube
> = 12.8mm
>
> 2) From the top of the headtube to the top of the forks thread, with
> the existing headset locking ring removed, = 22.5mm
>
> 3) Therefore, is the stack height 12.8 + 22.5 = 35.3 ?????
>
> Many thanks in advance for all your speedy replies - this is an
> emergency as I haven't got my summer bike together yet either.

if you happened to need spacers, these guys have some carbon spacer at
really low prices
http://www.bikingthings.com/2fihesp11cas.html

 

[John Thompson]

On 2008-05-11, [email protected] <[email protected]> wrote:

> Many Thanks Andrew - any idea of the parameters involved..? If the
> frame stack height is, say 35.3mm, a 34mm stack height headset is OK
> or too small or a 36mm stack height headset is OK or too big?

If the headset stack is too small you can always add spacers to make up
the difference. If it's too tall, you're generally SOL.

--

John ([email protected])