Threaded versus threadless headset

wrote in part:

To paraphrase the OP's question: "Is the design so much better that
it's worth the money, time, and trouble to switch from threaded to
threadless?". Both systems have advantages and disadvantages but
neither has such an overwhelming advantage over the other that an
otherwise unnecessary- no broken parts, etc- switch is worth it.

That depends on whether the old system is a burden on maintenance and
safety. I'm going to change because I have had enough problems with
quill stems to warrant it. Besides, the safety margin in a 0.975 dia
aluminum stem is nowhere near that of a 1.25 dia tubular stem.

IOW, we agree that the utility of changing from one system to another is
dependent on if you've had problems with the system you are using. You've had
problems so you will change. The OP didn't mention any problems and IIRC has
decided not to change.

Regards,
Bob Hunt

wrote in news:Rv81b.13860$dk4.490375
@typhoon.sonic.net:

That depends on whether the old system is a burden on maintenance and
safety. I'm going to change because I have had enough problems with
quill stems to warrant it. Besides, the safety margin in a 0.975 dia
aluminum stem is nowhere near that of a 1.25 dia tubular stem.

Jobst Brandt

Palo Alto CA

Now there's logic for you! Assuming that your 1.25" steerer and your
0.975" quill were not hollow and there were made of similar materials then
your conclusion of a higher safety margin would be sound. But they are
not. The wall thickness of a steerer is much less than that of a quill.
Even though the outside diameter of the steerer is much larger the quill
retains it's strength with increased wall thickness. Besides if you are
breaking your quills then you need to take up a different activity.

AL

On Fri, 22 Aug 2003 13:18:00 GMT, Al Frost wrote:

wrote in news:Rv81b.13860$dk4.490375
@typhoon.sonic.net:

That depends on whether the old system is a burden on maintenance and
safety. I'm going to change because I have had enough problems with
quill stems to warrant it. Besides, the safety margin in a 0.975 dia
aluminum stem is nowhere near that of a 1.25 dia tubular stem.

Jobst Brandt

Palo Alto CA

Now there's logic for you! Assuming that your 1.25" steerer and your
0.975" quill were not hollow and there were made of similar materials
then your conclusion of a higher safety margin would be sound. But they
are not. The wall thickness of a steerer is much less than that of a
quill. Even though the outside diameter of the steerer is much larger
the quill retains it's strength with increased wall thickness. Besides
if you are breaking your quills then you need to take up a different
activity.

AL


Personally, I cannot tell any strength difference between my quill stem on
my old Trek and the threadless system on my new LeMond.

--
Bob M in CT
Remove 'x.' to reply

Al Frost writes:

That depends on whether the old system is a burden on maintenance
and safety. I'm going to change because I have had enough problems
with quill stems to warrant it. Besides, the safety margin in a
0.975 dia aluminum stem is nowhere near that of a 1.25 dia tubular
stem.

Now there's logic for you! Assuming that your 1.25" steerer and
your 0.975" quill were not hollow and there were made of similar
materials then your conclusion of a higher safety margin would be
sound. But they are not. The wall thickness of a steerer is much
less than that of a quill. Even though the outside diameter of the
steerer is much larger the quill retains it's strength with
increased wall thickness. Besides if you are breaking your quills
then you need to take up a different activity.

Oops! The strength of a round cross section is given primarily by its
outside diameter. That is why bicycle frames are made of thin walled
tubing instead of solid bars. Most of the aluminum inside the stem is
just excess weight. Meanwhile consider the thin skin of an aircraft.

Jobst Brandt

Palo Alto CA

In article ,
says...

David L. Johnson wrote in message ...

With a quill stem (that is, with a threaded fork and headset),

Dave, when was the last time you saw anyone
riding with those old things, these days
everyone ride threadless.

I don't know about Dave, but when I looked down momentarily while riding
ride yesterday, I saw a quill stem! Egads!

And if you do see guys with quill stems on the
next ride then find another group to ride with,
because they are the 'B' group. Those are
probably the same lamers that are running
conventional 32 spoke wheels. Not the types
you want to been seen with!

Yes, you're obviously right. Equipment makes the man.

Rick

wrote in message
...

Oops! The strength of a round cross section is given primarily by its
outside diameter. That is why bicycle frames are made of thin walled
tubing instead of solid bars. Most of the aluminum inside the stem is
just excess weight. Meanwhile consider the thin skin of an aircraft.

Hey Jobst, aren't the aluminum walls of a quill stem thicker so they can
deal with the compression load applied when the center bolt is used to
tighten the wedge?

-Buck

Buck who? writes:

Oops! The strength of a round cross section is given primarily by its
outside diameter. That is why bicycle frames are made of thin walled
tubing instead of solid bars. Most of the aluminum inside the stem is
just excess weight. Meanwhile consider the thin skin of an aircraft.

Hey Jobst, aren't the aluminum walls of a quill stem thicker so they
can deal with the compression load applied when the center bolt is
used to tighten the wedge?

They were mostly made with a conical expander, for which a thicker
body was necessary but when they switched to the slant wedge, nothing
was changed. They easily could have been made thinner. Local riders
bored out the horizontal shaft of Cinelli stems.

Jobst Brandt

Palo Alto CA

On Thu, 21 Aug 2003 18:50:25 GMT,
wrote:

That depends on whether the old system is a burden on maintenance and
safety. I'm going to change because I have had enough problems with
quill stems to warrant it. Besides, the safety margin in a 0.975 dia
aluminum stem is nowhere near that of a 1.25 dia tubular stem.

Indeed, 0.975 diameter aluminum is not a lot, especially when it is
getting gouged by the top edge of the steer tube. But wouldn't a
steel stem solve this problem and the problem of the stuck stems? Or
are those clamps for track bikes that fit on the stem where it goes
into the steerer a better solution?

Jennifer D

Jennifer Donleavy writes:

That depends on whether the old system is a burden on maintenance
and safety. I'm going to change because I have had enough problems
with quill stems to warrant it. Besides, the safety margin in a
0.875 dia aluminum stem is nowhere near that of a 1.25 dia tubular
stem.

Indeed, 0.875 diameter aluminum is not a lot, especially when it is
getting gouged by the top edge of the steer tube. But wouldn't a
steel stem solve this problem and the problem of the stuck stems?
Or are those clamps for track bikes that fit on the stem where it
goes into the steerer a better solution?

Now that you mention it, that's the setup (with track clamp) I have
but I still don't like the way it performs. I climb hills standing
and find the forward reach of the stem and its 0.875 dia post an
unnecessary torsion bar between me and the bicycle. I'm looking
forward to a new fork with suitable steertube to get rid of that.

Jobst Brandt

Palo Alto CA

On Fri, 22 Aug 2003 21:07:39 GMT,
wrote:


Now that you mention it, that's the setup (with track clamp) I have
but I still don't like the way it performs. I climb hills standing
and find the forward reach of the stem and its 0.875 dia post an
unnecessary torsion bar between me and the bicycle.

Yeah, I know! Are those track clamps even available anymore? I can't
find one anywhere. Did you buy it recently or is it from the old
days?

I'm looking
forward to a new fork with suitable steertube to get rid of that.

What about a steel stem? That's the solution I am considering --
having a tubular steel stem tig welded by a local frame builder.
Would that be a good, safe solution? Do they break from the notching
like I am expecting my current stem to do?

Jennifer D