Threaded versus threadless headset

On Wed, 20 Aug 2003 17:25:49 -0400, Rick Onanian wrote:

On Wed, 20 Aug 2003 16:28:41 -0400, David L. Johnson
wrote:
Yes, it's simple enough to re-adjust, though I do not like the idea of
trying to adjust the preload if the bearings are not clean and well-
lubed.

Okay, now I'm a bit afraid again. I've never heard
of the term "preload" applied to anything other
than suspension.

What is "preload" in this context, and how should I
check / adjust it?

Like I said, I've changed stems a couple times on
my threadless road bike, and haven't noticed any
looseness or maladjustment from it...and have had
my longest and fastest ride ever just a few days
ago.


Preload, I think, is just the "load" put on the bearings when you tighten
the bolt in the cap. If you want to know for sure what's going on, take
apart your bike. It's easy to do and will show you how everything works.
I built my mountain bike from the ground up (ordered the frame, the parts,
the wheels, etc.). It's not hard to do.

--
Bob M in CT
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On Wed, 20 Aug 2003 21:32:17 GMT, Bob M wrote:
Preload, I think, is just the "load" put on the bearings when you tighten

Good. I tightened it nicely every time.

the bolt in the cap. If you want to know for sure what's going on, take
apart your bike. It's easy to do and will show you how everything works.

I have quite the collection of beaters I can experiment
on, lately. I should do that. Heck, I even have a birthday
coming up; maybe I'll ask for a tool kit.

I built my mountain bike from the ground up (ordered the frame, the
parts, the wheels, etc.). It's not hard to do.

I'd like to do that sometime...I just lack the money.

--
Rick Onanian

"Hjalmar Duklæt" wrote:

What's the advantage of a threadless headset over an oldfashioned threaded
one? Is the threaded one stiffer/lighter?

Threadless systems are significantly stiffer, sometimes lighter, and
less likely to suffer structural failure than quill stem systems, for
any given materials and tolerances. This is primarily due to the
categorical superiority of an external binder clamp vs. an internal
expander wedge, but also due to the weakening effect of steerer
threads.

The other advantage of threadless headset systems is that the steerer
tube wall thickness is not dictated by the assembly, allowing the use
of materials besides steel (or the use of different thicknesses of
steel).

There is a cost benefit of threadless forks to manufacturers and
distributors, because all sizes of frames may be accommodated with a
single type of fork. Note however that the cheapest mass-market
bikes, which were only ever offered in one size, have retained quill
stems and threaded headsets.

Would it improve my riding in any
way going from threaded to threadless?

Not noticeably. If your bike is already set up, there is no
compelling reason to swap systems unless you must replace your fork.

Chalo Colina

To the guy that claimed he ripped a quill stem out of a head tube. This
just seems hihgly unlikely and probably you never had the stem bolt
tightened in there to begin with. They've raced 100 years of the Tour de
France on quill stems with the strongest sprinters of the time and never
once has a quill stem come close to being pulled out of a head tube.



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"Fabrizio Mazzoleni" wrote in message .ca...
David L. Johnson wrote in message ...

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

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!

Not at all; my wheels are either 36H, or 40H, 3X and tied and soldered ;-)
It all fits perfectly well with my quill stem, Brooks saddle, and sandals
as my footware :-)

- rick

writes:

"Threadless headset" is a lame name for an improvement that had such a
long time to market. The quill stem, aka, the creaking, wobbling,
permanently stuck stem, was always a weak part on the bicycle that has
been relieved of duty by this innovation. The main feature is not the
headset with its lack of threads, but the stem and its solid reliable
and removable attachment to the steer tube. However, the head bearing
can be adjusted in a trifle, without two ungainly 8-point end
wrenches. The whole job can be done with an Allen wrench. Besides
that, for the weight weenies, it's lighter.

For safety and reliability, get a stem that has two screws on the
steer tube end and four on the front plate so that a one screw failure
will not let the handlebar go free.

I recently put a Ritchey WCS stem on my bike.
That stem is only one I know of with the 4-bolt/2-bolt design you
describe.

If you ever pack your bike in a box or a bike suitcase for travel,
usually you have to turn the handlebars sideways. With a quill stem you
loosen the expander wedge, drop the stem and twist; then reverse the
process to unpack. With threadless you loosen the stem clamp and twist
the stem on the steerer but you have to readjust the pre-load when you
unpack; a minor difference. EXCEPT with my Klein's internal headset the
bearings are bonded to the inside of the head tube and the fork is
bonded to the bearing cartridges so there is no pre-load adjustment; in
fact the spacers are just cosmetic and there is no top cap at all -
just a rubber plug. They changed this in 2002 to go with the
star-fangled nut design.



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On Wed, 20 Aug 2003 16:52:23 -0400, Rick Onanian
may have said:

On Wed, 20 Aug 2003 18:31:12 GMT, Werehatrack
wrote:
As one who has yanked the quill entirely out of the tube, I can tell
you that this is a dangerous assumption to make. Riders can and will
*pull* on the bars when pedalling hard. Sometimes hard *vertically*.
This remains true whether it's advisable and safe or not. This would
seem to mitigate in favor of the threadless design; the attachment
method is probably stronger, but as you note, the reality is that

Stronger or not, the threadless may give more
warning. You may notice that it's working it's
way off the steerer earlier than you would notice
a threadless working it's way out of the head.

I don't know. I've never had either one happen.

I'd think a threadless would have to get detectably sloppy before it
would work its way up much, but I've had a threaded quill (of
admittedly low-end design) that was able to work up in the tube past
the min insert line with time, even though it still seemed to be
tight. The Ritchey in one of my other bikes gets more strain and
never budges so much as a millimeter, though, so it's obviously
possible to make a threaded quill that will resist my abuse.

That said, threaded still seems to make more sense to me. Maybe I'm
just a reactionary, but I just can't see that there's any important
advantage *for me* in the threadless setups. That might change
someday, but it will probably be a while.

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"Hjalmar Duklæt" wrote in message
...
Hi,
What's the advantage of a threadless headset over an oldfashioned threaded
one? Is the threaded one stiffer/lighter? Would it improve my riding in
any
way going from threaded to threadless?
Hjalmar



Many thanks to all who have made their comments on my issue. My conclusion
is that I really don't need to swap fork/stem on my Trek 5500. I don't have
problems riding with other riders because of this obsolete setup, I like to
be able to change the hight of the bar without to much fuss, I also
regularly check that the stem is not stuck in the steerer (after having to
use a hacksaw to get the stem out of another bike/fork) and it probably will
not improve my sprint due to its better rigidness. Finally, I'll save a lot
of money.
Hjalmar

wrote in message ...
I don't see that happening more than once or twice a year... every 5000
miles.

Most excellent drive-by gloat.

Dick Durbin