Handlebar stem height

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

There's no 'minimum' mark visible on the stem. It's a Cinelli one if
that makes any difference, and has clearly been used at many heights
over the years as it's noticeably knurled, so it's possible any marks
have just been erased, so how do I know how high it can safely go?

Stick it in as far as it will go, make a mark (there's quite possibly a
mark there already where the headset has dug in), take it out and
measure halfway between the mark and the end - that's about the right
place.

On Fri, 20 Jul 2007 14:37:23 +0100, Rob Morley <[email hidden]>

Quoted message said:

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

There's no 'minimum' mark visible on the stem. It's a Cinelli one if
that makes any difference, and has clearly been used at many heights
over the years as it's noticeably knurled, so it's possible any marks
have just been erased, so how do I know how high it can safely go?

Stick it in as far as it will go, make a mark (there's quite possibly a
mark there already where the headset has dug in), take it out and
measure halfway between the mark and the end - that's about the right
place.

There are lots of marks, which is probably why I can't see a minimum
one, but following your advice would put it lower into the headset
than any of the existing marks, whereas I'm trying to raise it; so
thanks, but I think you may have the wrong idea.

--
Ace in Basel - brucedotrogers a.t rochedotcom

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

On Fri, 20 Jul 2007 14:37:23 +0100, Rob Morley <[email hidden]>

Quoted message said:

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

There's no 'minimum' mark visible on the stem. It's a Cinelli one if
that makes any difference, and has clearly been used at many heights
over the years as it's noticeably knurled, so it's possible any marks
have just been erased, so how do I know how high it can safely go?

Stick it in as far as it will go, make a mark (there's quite possibly a
mark there already where the headset has dug in), take it out and
measure halfway between the mark and the end - that's about the right
place.

There are lots of marks, which is probably why I can't see a minimum
one, but following your advice would put it lower into the headset
than any of the existing marks, whereas I'm trying to raise it; so
thanks, but I think you may have the wrong idea.

I assure you I understood the question - I wonder which bit of my answer
you didn't understand. Just to be sure I measured a 1980s Cinelli stem,
and it turns out that the minimum insertion is 55mm, while my
guesstimate method would have put it at about 42mm - the stem doesn't go
down as far as I'd have expected.

in message <[email hidden]>, Ace

(') said:

On Fri, 20 Jul 2007 14:37:23 +0100, Rob Morley <[email hidden]>

Quoted message said:

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

There's no 'minimum' mark visible on the stem. It's a Cinelli one if
that makes any difference, and has clearly been used at many heights
over the years as it's noticeably knurled, so it's possible any marks
have just been erased, so how do I know how high it can safely go?

Stick it in as far as it will go, make a mark (there's quite possibly a
mark there already where the headset has dug in), take it out and
measure halfway between the mark and the end - that's about the right
place.

There are lots of marks, which is probably why I can't see a minimum
one, but following your advice would put it lower into the headset
than any of the existing marks, whereas I'm trying to raise it; so
thanks, but I think you may have the wrong idea.

If it is, as I take it it is, a stem for an old fashioned threaded headset,
at the bottom is the wedge which tightens it in place. Above the wedge
there is often a slot in both sides of the tube, through which the threads
of the bolt which tightens the wedge can be seen. The minimum insertion
point is normally between 20 and 25mm above the highest point of the slot.

It may well be that this stem cannot safely be raised as high as you want.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; All in all you're just another hick in the mall
-- Drink C'lloid

On Fri, 20 Jul 2007 15:24:25 +0100, Rob Morley <[email hidden]>

Quoted message said:

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

On Fri, 20 Jul 2007 14:37:23 +0100, Rob Morley <[email hidden]>

Quoted message said:

In article <[email hidden]>, Ace
[email hidden] says...

> There's no 'minimum' mark visible on the stem. It's a Cinelli one if
> that makes any difference, and has clearly been used at many heights
> over the years as it's noticeably knurled, so it's possible any marks
> have just been erased, so how do I know how high it can safely go?
>
>
Stick it in as far as it will go, make a mark (there's quite possibly a
mark there already where the headset has dug in), take it out and
measure halfway between the mark and the end - that's about the right
place.

There are lots of marks, which is probably why I can't see a minimum
one, but following your advice would put it lower into the headset
than any of the existing marks, whereas I'm trying to raise it; so
thanks, but I think you may have the wrong idea.

I assure you I understood the question - I wonder which bit of my answer
you didn't understand. Just to be sure I measured a 1980s Cinelli stem,
and it turns out that the minimum insertion is 55mm, while my
guesstimate method would have put it at about 42mm - the stem doesn't go
down as far as I'd have expected.

OIC. Where does the 55mm figure come from?
--
Ace in Basel - brucedotrogers a.t rochedotcom

Simon Brooke said:

in message <[email hidden]>, Ace

(') said:

On Fri, 20 Jul 2007 14:37:23 +0100, Rob Morley <[email hidden]>

Quoted message said:

In article <[email hidden]>, Ace
[email hidden] says...

> There's no 'minimum' mark visible on the stem. It's a Cinelli one if
> that makes any difference, and has clearly been used at many heights
> over the years as it's noticeably knurled, so it's possible any marks
> have just been erased, so how do I know how high it can safely go?

Quoted message said:

If it is, as I take it it is, a stem for an old fashioned threaded headset,
at the bottom is the wedge which tightens it in place.

Yes, it's an "old-fashioned" one, but with an expander rather than a
wedge.

Quoted message said:

Above the wedge
there is often a slot in both sides of the tube, through which the threads
of the bolt which tightens the wedge can be seen. The minimum insertion
point is normally between 20 and 25mm above the highest point of the slot.

I think that would still apply though. Indeed, that sounds like the
type you're describing, as I don't think the wedge types usually have
the slots in them.

Quoted message said:

It may well be that this stem cannot safely be raised as high as you want.

Sounds like it, but it's no big deal - just thought I'd give it a try.

--
Ace in Alsace - brucedotrogers a.t rochedotcom

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

OIC. Where does the 55mm figure come from?

I measured the distance from the bottom of the quill to the minimum
insertion mark.

On Fri, 20 Jul 2007 17:22:18 +0100, Rob Morley <[email hidden]>

Quoted message said:

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

OIC. Where does the 55mm figure come from?

I measured the distance from the bottom of the quill to the minimum
insertion mark.

Great, thanks. That did actually allow me to raise it a little bit,
perhaps 1.5cm, and I reckon my legs must have shrunk[1], 'cos the
saddle wanted dropping by a couple too.

Just been out for a couple of miles, then followed the same route on
my new Focus for comparison. Oddly, the bent-forward position of the
Mercian was actually less painful than the more upright MTB, although
overall, the latter was more comfortable.

I'll have to wait a while to see if it's better over a longer
distance, as the rides were about enough for me in my current state.
Still, recovery continues well...

[1] More likely, when I last used it I was very fit, so probably had a
greater level of flexibility in the pelvis than I do now.
--
Ace in Alsace - brucedotrogers a.t rochedotcom

In article <[email hidden]>, Ace
[email hidden] says...

Quoted message said:

Just been out for a couple of miles, then followed the same route on
my new Focus for comparison. Oddly, the bent-forward position of the
Mercian was actually less painful than the more upright MTB, although
overall, the latter was more comfortable.

Leaning forward tends to reduce compressive load on the spine, reducing
jarring from road shock. It does place more stress on the lower back
muscles, and requires more weight to be supported by the arms (unless
you're working hard so more load is taken by the legs), so can be more
tiring.