Movement in stem

DRS said:

I hope I've got my terminology right. I have a Shogun
hybrid and I recently changed the angle where the stem
meets the fork. I dropped it so that the stem is now
nearly horizontal (it was about 45° up), thus moving
the handlebars a touch lower and further away from me.
I adjusted the angle of the handlebars themselves to
suit and then the bits attached to the handlebars. So
far, so good.

The problem is that there is now slight but perceivable
movement in the stem, up or down depending on whether I'm
leaning on or pulling back the handlebars. It's most
disconcerting. There are two relevant bolts, one
horizontal through the circular bits at the fork end and
one underneath the stem and vertical to it, that I've
tightened to the point where I fear my Allen key is about
to snap, yet there is still this movement. Is this normal?
Or have I buggered something up?

The horizontal bolts are not meant to be loosened or
tightened. They are torqued on precisely and are not needed
to make adjustments to the stem.

The vertical bolt underneath is the only one you should need
to adjust. It probably clamps down on a grooved piece which
locks the stem into place when the grooves are engaged. If
this is tight, and the grooved piece is seated properly, you
should take your bike into a LBS to have it looked at, a
stem is not a nice thing to have break.

Jacobe Hazzard <[email hidden]> wrote in
message [email hidden]-
e.rogers.com

Quoted message said:

DRS wrote:

[...]

Quoted message said:

Quoted message said:

The problem is that there is now slight but perceivable
movement in the stem, up or down depending on whether I'm
leaning on or pulling back the handlebars. It's most
disconcerting. There are two relevant bolts, one
horizontal through the circular bits at the fork end and
one underneath the stem and vertical to it, that I've
tightened to the point where I fear my Allen key is about
to snap, yet there is still this movement. Is this
normal? Or have I buggered something up?

The horizontal bolts are not meant to be loosened or
tightened. They are torqued on precisely and are not
needed to make adjustments to the stem.

Rightly or wrongly, if I don't loosen the horizontal bolt
somewhat then I can't adjust the angle of the stem even if
the vertical bolt is removed.

Quoted message said:

The vertical bolt underneath is the only one you should
need to adjust. It probably clamps down on a grooved piece
which locks the stem into place when the grooves are
engaged. If this is tight, and the grooved piece is seated
properly, you should take your bike into a LBS to have it
looked at, a stem is not a nice thing to have break.

I loosened both bolts, reseated everything and retightened
them. It seems to have done the trick.

--

"I'm proud that I live in a country where witnessing two
hours of bloody, barbarous torture in gloating detail is
considered indicia of religious piety, whereas a mere second
gazing upon a woman's breast is cause for outraged
apoplexy." Betty Bowers,
bettybowers.commelgibsonpassion.htmlOpen ↗

You seem to be describing a quill type stem (that is
inserted into the fork) not a newer "A-headset" (externally
clamped) type.

In that case you should loosen completely the bolt clamping
the stem into the fork (you may need to tap it to dislodge
the wedge after you loosen it about 3 turns) and then you
will be able to feel just how loose a fit in the fork it
is. It should be shimmed to a very close (almost tight)
fit. This is best done with brass shim stock of
whatever thickness will allow its being wrapped
completely around one time (usually about .003"-.006"😉,
but can also be done with a scrap of aluminum flashing
or even a beverage can. If you haven't got the ideal
thickness you can overlap it. It's a good idea to taper
the bottom end to facilitate insertion into the fork.
The shim should end up as a cylinder around the very
top of the steerer tube, right under the headset top
nut, but if some is visible it won't hurt anything. It
only needs to be about an inch in depth. When you re-
tighten the wedge, you will have a wiggle-free
connection. One last word: everything on a stem should
be greased (threads, wedge, shim, inside of steerer)
-except- for the bar-stem interface. Mark Pace Pace
Bicycle Haven Independence, MO 64050

MAPaceBike <[email hidden]> wrote in message 20040323045657.27032.00000224@mb-
m21.aol.com

Quoted message said:

You seem to be describing a quill type stem (that is
inserted into the fork) not a newer "A-headset"
(externally clamped) type.

In that case you should loosen completely the bolt
clamping the stem into the fork (you may need to tap it to
dislodge the wedge after you loosen it about 3 turns) and
then you will be able to feel just how loose a fit in the
fork it is. It should be shimmed to a very close (almost
tight) fit.

The bit that clamps onto the fork proper has three bolts,
one vertical and two horizontal. Those I haven't touched.
The point of interest is the hinge bit - where I changed
the angle. That's where the one horizontal and one
vertical bolts are. The movement (before I redid them) was
not horizontal, it was vertical, up when I pulled on the
handlebars and down when I leaned forward, pivoting on
this hinge.

The stem has "Tioga" on it but I can't find it on the Tioga
website (or any other site for that matter) which is a right
pain because I'd love to be able to show what it looks like.
It's easy enough to find pictures of individual components
but oddly enough I've yet to come across a site which has a
decent picture of a bike with little arrows pointing to the
various bits identifying what's what and where (and
variations thereon).

--

"I'm proud that I live in a country where witnessing two
hours of bloody, barbarous torture in gloating detail is
considered indicia of religious piety, whereas a mere second
gazing upon a woman's breast is cause for outraged
apoplexy." Betty Bowers,
bettybowers.commelgibsonpassion.htmlOpen ↗