Movement in stem

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?

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DRS wrote:
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 wrote in message
le.rogers.com
DRS wrote:

[...]

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.

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, http://www.bettybowers.com/melgibsonpassion.html

Jacobe Hazzard wrote in message
le.rogers.com
DRS wrote:

[...]

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.

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, http://www.bettybowers.com/melgibsonpassion.html

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

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 wrote in message

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, http://www.bettybowers.com/melgibsonpassion.html

MAPaceBike wrote in message

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, http://www.bettybowers.com/melgibsonpassion.html