Threadless steer tube length

damyth said:

Velonews recently had an interesting tidbit in the Tech Corner:
http://www.velonews.com/tech/report/articles/11432.0.html

<quote>
The number and placement of spacers does have an effect on the fatigue
life of an aluminum steerer tube. Running less than 5mm of spacers
under the stem can concentrate or "point load" a great deal of stress
in one spot on the steerer. Therefore, Bontrager recommends a minimum
of 5mm, and a maximum of 40mm of spacers between the stem and the
headset to maximize the fatigue life of the steerer.
Scott Daubert
Trek Bicycles
</quote>

The 40mm upper limit was news to me (and the number of spacers). (I
run mine ~52mm.) 40mm measured from where exactly?? I mean some
threadless headsets come with a longer "top cap," in fact, they are
available in different lengths.

Is this Trek just covering their own ass, or does this apply to
aluminum steerers in general? Heck, maybe we should just go back to
using steel.

We use 4cm for carbon steerers(1 1/8inch, 2.5cm for 1 inch)...from the
top part if the headset to under the stem. We don't have a max for
aluminum or steel steerers but if you are getting way up there, like
5-6cm, they 'may' be a problem with the bike fit.

Ask Mike about Trek/Bontrager.

On 10 Jan 2007 01:48:10 -0800, "damyth"

may have said:

Velonews recently had an interesting tidbit in the Tech Corner:
http://www.velonews.com/tech/report/articles/11432.0.html

<quote>
The number and placement of spacers does have an effect on the fatigue
life of an aluminum steerer tube. Running less than 5mm of spacers
under the stem can concentrate or "point load" a great deal of stress
in one spot on the steerer. Therefore, Bontrager recommends a minimum
of 5mm, and a maximum of 40mm of spacers between the stem and the
headset to maximize the fatigue life of the steerer.
Scott Daubert
Trek Bicycles
</quote>

The 40mm upper limit was news to me (and the number of spacers). (I
run mine ~52mm.) 40mm measured from where exactly?? I mean some
threadless headsets come with a longer "top cap," in fact, they are
available in different lengths.

Is this Trek just covering their own ass, or does this apply to
aluminum steerers in general? Heck, maybe we should just go back to
using steel.

I'm pretty sure that this is a YMMV issue. I've noticed that some
aluminum steerers seem more flexible than others, and it's likely that
the stiffer ones can accept more spacers than the limber ones.

If I have a choice, I stick with steel steerers for a variety of
reasons...but I'll use aluminum if that's what is on the fork that I
need for a given bike.

--
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.

Werehatrack said:

If I have a choice, I stick with steel steerers for a variety of
reasons...but I'll use aluminum if that's what is on the fork that I
need for a given bike.

Could you please give a threadless example of a Steel, or are you
talking oem?

Thanks
Stems and Seeds Blues

On 10 Jan 2007 09:19:59 -0800, "ddog" <[email hidden]> may

have said:

Werehatrack said:

If I have a choice, I stick with steel steerers for a variety of
reasons...but I'll use aluminum if that's what is on the fork that I
need for a given bike.

Could you please give a threadless example of a Steel, or are you
talking oem?

Surely you jest; have you not checked what's out there? While
aluminum is plentiful, at the lower end of aftermarket (and into the
midrange in places) steel is still quite common. Certainly all of the
non-suspension *steel forks* still have steel steerers, and some
suspension forks do as well.

--
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.

Werehatrack said:

Surely you jest; have you not checked what's out there? While
aluminum is plentiful, at the lower end of aftermarket (and into the
midrange in places) steel is still quite common. Certainly all of the
non-suspension *steel forks* still have steel steerers, and some
suspension forks do as well.

Lol, non-supension steel forks, for my 27" wheels, are $27 forks at the
MOST. I have a selective market to choose from, since want to maintain
my British handling. It really is worth preserving.

And to preserve it, I can really only do a threadless converter stem
without new forks since no reasonable threadless fork choice for 27"
wheels. I keep forgetting. I'll have to investigate other steel alloys
closer to steel in the converter stems and stems too. But I'll keep
mine until I have to switch. Most LBS just carry one threadless stem
converter, or either you have to look through 15 different company
links.

I was just hoping that you may have a 'good' one you liked and provide
a link to get me started :-o

thanks!

ddog said:

Werehatrack said:

Surely you jest;

Nevermind, found this from another poster on this site for another
part. Looks good so far.

http://www.benscycle.net/index.php?main_page=product_info&cPath=75_128_143&products_id=601&zenid=284d83f1a22b2966c4dc56ff822d4001

Qui si parla Campagnolo said:

damyth said:

Velonews recently had an interesting tidbit in the Tech Corner:
http://www.velonews.com/tech/report/articles/11432.0.html

<quote>
The number and placement of spacers does have an effect on the fatigue
life of an aluminum steerer tube. Running less than 5mm of spacers
under the stem can concentrate or "point load" a great deal of stress
in one spot on the steerer. Therefore, Bontrager recommends a minimum
of 5mm, and a maximum of 40mm of spacers between the stem and the
headset to maximize the fatigue life of the steerer.
Scott Daubert
Trek Bicycles
</quote>

The 40mm upper limit was news to me (and the number of spacers). (I
run mine ~52mm.) 40mm measured from where exactly?? I mean some
threadless headsets come with a longer "top cap," in fact, they are
available in different lengths.

Is this Trek just covering their own ass, or does this apply to
aluminum steerers in general? Heck, maybe we should just go back to
using steel.

We use 4cm for carbon steerers(1 1/8inch, 2.5cm for 1 inch)...from the
top part if the headset to under the stem. We don't have a max for
aluminum or steel steerers but if you are getting way up there, like
5-6cm, they 'may' be a problem with the bike fit.

Ask Mike about Trek/Bontrager.

In my case it's not really a "fit" issue. I just like to be on the
conservative side of having too long a steerer than one cut too short.
Because of this, I also orient the stem such that it has the least
rise. I I orient the stem the other way I can easily cut off another
20mm of the steerer (which I want to avoid doing.)

My point earlier with regarding the "top cap" of the headset is that it
comes in variable lengths (I've seen some as high as 30mm), so the 40mm
"maximum" quoted by Trek seems rather arbitrary (in actual steerer
length).

The bike makers dont want to include longer steerers cuz they dont look
racer- The racy looking bikes sell. Only if the delers got guts and
forced the makers to leave steerer uncut would the ahead system be
comfortable for most riders. Most dealers have 1 year or more tune up
policies so why not let a customer ride the bike for a bit then cut the
steerer. It's easy to take more off and only takes a few but you cant
put it back.

damyth said:

Velonews recently had an interesting tidbit in the Tech Corner:
http://www.velonews.com/tech/report/articles/11432.0.html

<quote>
The number and placement of spacers does have an effect on the fatigue
life of an aluminum steerer tube. Running less than 5mm of spacers
under the stem can concentrate or "point load" a great deal of stress
in one spot on the steerer. Therefore, Bontrager recommends a minimum
of 5mm, and a maximum of 40mm of spacers between the stem and the
headset to maximize the fatigue life of the steerer.
Scott Daubert
Trek Bicycles
</quote>

The 40mm upper limit was news to me (and the number of spacers). (I
run mine ~52mm.) 40mm measured from where exactly?? I mean some
threadless headsets come with a longer "top cap," in fact, they are
available in different lengths.

Is this Trek just covering their own ass, or does this apply to
aluminum steerers in general? Heck, maybe we should just go back to
using steel.

damyth said:

Velonews recently had an interesting tidbit in the Tech Corner:
http://www.velonews.com/tech/report/articles/11432.0.html

You did notice the response was contrary to the question, didn't you?

Quoted message said:

The 40mm upper limit was news to me (and the number of spacers). (I
run mine ~52mm.) 40mm measured from where exactly?? I mean some
threadless headsets come with a longer "top cap," in fact, they are
available in different lengths.

Is this Trek just covering their own ass, or does this apply to
aluminum steerers in general? Heck, maybe we should just go back to
using steel.

It may be specific to the forks Trek uses on its Bontrager models.
That there is an upper limit makes sense -- how much unsupported lever
is safe on the fork? I suspect that 40 mm is a general rule of thumb;
heavier riders, or riders who stress their bikes more, should probably
try to keep the spacers lower.

But why do they specify a minimum 5 mm spacer? Why is a spacer
necessary at all?

Pat

Email address works as is.

damyth said:

Velonews recently had an interesting tidbit in the Tech Corner:
http://www.velonews.com/tech/report/articles/11432.0.html

<quote>
The number and placement of spacers does have an effect on the fatigue
life of an aluminum steerer tube. Running less than 5mm of spacers
under the stem can concentrate or "point load" a great deal of stress
in one spot on the steerer. Therefore, Bontrager recommends a minimum
of 5mm, and a maximum of 40mm of spacers between the stem and the
headset to maximize the fatigue life of the steerer.
Scott Daubert
Trek Bicycles
</quote>

The 40mm upper limit was news to me (and the number of spacers). (I
run mine ~52mm.) 40mm measured from where exactly?? I mean some
threadless headsets come with a longer "top cap," in fact, they are
available in different lengths.

Is this Trek just covering their own ass, or does this apply to
aluminum steerers in general? Heck, maybe we should just go back to
using steel.

What do you mean "go back to"?

AFAIK, both the headset or the spacers bear on plastic (at least as I
recall from the ones I've installed). Putting any "sleeve", whether stem
or spacer, would make the steerer stiffer, but if the reinforced section
bears on easily deformed plastic, I don't see that it makes mush (typo,
but decided to leave it) difference.

Sounds like weasel words to me: "You can do it, but you really shouldn't".

Quoted message said:

Werehatrack said:

Surely you jest; have you not checked what's out there? While
aluminum is plentiful, at the lower end of aftermarket (and into the
midrange in places) steel is still quite common. Certainly all of the
non-suspension *steel forks* still have steel steerers, and some
suspension forks do as well.

ddog said:

Lol, non-supension steel forks, for my 27" wheels, are $27 forks at the
MOST. I have a selective market to choose from, since want to maintain
my British handling. It really is worth preserving.

And to preserve it, I can really only do a threadless converter stem
without new forks since no reasonable threadless fork choice for 27"
wheels. I keep forgetting. I'll have to investigate other steel alloys
closer to steel in the converter stems and stems too. But I'll keep
mine until I have to switch. Most LBS just carry one threadless stem
converter, or either you have to look through 15 different company
links.

I was just hoping that you may have a 'good' one you liked and provide
a link to get me started :-o

If you're picky, custom built forks are not all that expensive. Since
you have a specific geometry in mind, you can specify height, rake and
column. Heck, you can even choose curved or 'angled' blades!

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