Some math help please

Bestest Handsander said:

I admit it. I have an English degree, so a little help here would be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle of the
handbar top tube. The current stem is 120mm, 84 degrees.

The Question: How much height to I gain if I flip the stem over so that it's
96 degrees from the steerer tube? Also, does flipping it over change the
reach from the tip of the saddle?

Thanks!

Here, take a look at this chart:
http://www.habcycles.com/fitting.html

Life is Good!
Jeff

In article <[email hidden]>,
"Bestest Handsander" <[email hidden]>

Quoted message said:

I admit it. I have an English degree, so a little help here would be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle of the
handbar top tube. The current stem is 120mm, 84 degrees.

The Question: How much height to I gain if I flip the stem over so that it's
96 degrees from the steerer tube? Also, does flipping it over change the
reach from the tip of the saddle?

What is the head tube angle, beta?

2 * 120 * sin(6 deg) * sin beta.

Suppose beta = 70, 71, 72, 73 deg
then the increment is
23.6, 23.7, 23.9, 24.0 mm.

What is the name of Lady Macbeth's dog?

--
Michael Press

I think the rise will be about 25 mm, and the travel backwards about 5
mm. I wouldn't be concerned about the 5 mm, it's small and in the
direction of more comfort.

The solution is left as an exercise for the students. Be prepared for
a pop quiz.

Ken

"Michael Press" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article <[email hidden]>,
"Bestest Handsander" <[email hidden]>

Quoted message said:

I admit it. I have an English degree, so a little help here would
be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle
of the
handbar top tube. The current stem is 120mm, 84 degrees.

The Question: How much height to I gain if I flip the stem over so
that it's
96 degrees from the steerer tube? Also, does flipping it over
change the
reach from the tip of the saddle?

What is the head tube angle, beta?

2 * 120 * sin(6 deg) * sin beta.

Suppose beta = 70, 71, 72, 73 deg
then the increment is
23.6, 23.7, 23.9, 24.0 mm.

What is the name of Lady Macbeth's dog?

--
Michael Press

Bestest Handsander said:

I admit it. I have an English degree, so a little help here would be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle of the
handbar top tube.

Irrelevant.

Quoted message said:

The current stem is 120mm, 84 degrees.

But what's the head tube angle?

Quoted message said:

The Question: How much height to I gain if I flip the stem over so that it's
96 degrees from the steerer tube?

One point off for the assertion of having a degree in English, and
then committing a spelling error.

Without a precise head tube angle, this question can't be accurately
answered. However, for purposes of approximation, taking 72 degrees
as a likely figure, then the stem's angle above horizontal is changed
from 14 degrees to 22 degrees by the flip; the vertical change is then
((120 x sin(22))-(120 x sin(14)))mm, which is about 15mm of elevation.
The change in the horizontal position is only about 5mm. Neither of
these is a large value, though 15mm of additional bar height could be
enough to feel.

Quoted message said:

Also, does flipping it over change the
reach from the tip of the saddle?

As noted, yes, by a negligible 5mm.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Werehatrack said:

Bestest Handsander said:

I admit it. I have an English degree, so a little help here would be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle of the
handbar top tube.

Irrelevant.

Quoted message said:

The current stem is 120mm, 84 degrees.

But what's the head tube angle?

Quoted message said:

The Question: How much height to I gain if I flip the stem over so that it's
96 degrees from the steerer tube?

Quoted message said:

The answer is Tuesday, the 29th
One point off for the assertion of having a degree in English, and
then committing a spelling error.

Without a precise head tube angle, this question can't be accurately
answered. However, for purposes of approximation, taking 72 degrees
as a likely figure, then the stem's angle above horizontal is changed
from 14 degrees to 22 degrees by the flip; the vertical change is then
((120 x sin(22))-(120 x sin(14)))mm, which is about 15mm of elevation.
The change in the horizontal position is only about 5mm. Neither of
these is a large value, though 15mm of additional bar height could be
enough to feel.

Quoted message said:

Also, does flipping it over change the
reach from the tip of the saddle?

As noted, yes, by a negligible 5mm.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

"Werehatrack" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Bestest Handsander said:

I admit it. I have an English degree, so a little help here would be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle of the
handbar top tube.

Irrelevant.

Quoted message said:

The current stem is 120mm, 84 degrees.

But what's the head tube angle?

Quoted message said:

The Question: How much height to I gain if I flip the stem over so that
it's
96 degrees from the steerer tube?

One point off for the assertion of having a degree in English, and
then committing a spelling error.

Without a precise head tube angle, this question can't be accurately
answered. However, for purposes of approximation, taking 72 degrees
as a likely figure, then the stem's angle above horizontal is changed
from 14 degrees to 22 degrees by the flip; the vertical change is then
((120 x sin(22))-(120 x sin(14)))mm, which is about 15mm of elevation.
The change in the horizontal position is only about 5mm. Neither of
these is a large value, though 15mm of additional bar height could be
enough to feel.

Quoted message said:

Also, does flipping it over change the
reach from the tip of the saddle?

As noted, yes, by a negligible 5mm.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

LOL! Perhaps I should specify it was English Lit. Never was a good speller.
Headtube is 74 degrees, but the numbers you and the others provided are
close enough for my purposes.

Thanks all.

Bestest Handsander said:

I admit it. I have an English degree, so a little help here would be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle of the
handbar top tube. The current stem is 120mm, 84 degrees.

The Question: How much height to I gain if I flip the stem over so that it's
96 degrees from the steerer tube? Also, does flipping it over change the
reach from the tip of the saddle?

I have an engineering degree, but I'd just flip the stem and see what
happens. It would probably be quicker :-)

Werehatrack said:

Quoted message said:

Also, does flipping it over change the
reach from the tip of the saddle?

As noted, yes, by a negligible 5mm.

For me, that 5mm, while small, was enough to finish off my bike fit. A
year ago, I moved 15mm worth of spacers from below the stem to above
it, and flipped the stem. This gave me the same elevation, but got me
an "in between" stem length 🙂 It feels just about perfect now.

-Mike

"Zog The Undeniable" <[email hidden]> wrote in message
news:4432a325.0@entanet...

Quoted message said:

Bestest Handsander said:

I admit it. I have an English degree, so a little help here would be
appreciated.

My bike has a 592mm reach from the tip of the saddle to the middle of the
handbar top tube. The current stem is 120mm, 84 degrees.

The Question: How much height to I gain if I flip the stem over so that
it's 96 degrees from the steerer tube? Also, does flipping it over change
the reach from the tip of the saddle?

I have an engineering degree, but I'd just flip the stem and see what
happens. It would probably be quicker :-)

Don't have it. Trying to figure out exactly what stem I need. Although I
start cutting one out of paper, but the kids distracted me and by the time I
got back to it, people had already posted the info I needed.

Thanks again

Zog The Undeniable said:

Quoted message said:

The Question: How much height to I gain if I flip the stem over so that it's
96 degrees from the steerer tube? Also, does flipping it over change the
reach from the tip of the saddle?

I have an engineering degree, but I'd just flip the stem and see what
happens. It would probably be quicker :-)

I have a couple of math degrees, and that was going to be my suggestion as
well. it is possible to compute it, but it would be a PITA.

--

David L. Johnson

__o | And what if you track down these men and kill them, what if you
_`\(,_ | killed all of us? From every corner of Europe, hundreds,
(_)/ (_) | thousands would rise up to take our places. Even Nazis can't
kill that fast. -- Paul Henreid (Casablanca).

David L. Johnson said:

Zog The Undeniable said:

Quoted message said:

The Question: How much height to I gain if I flip the stem over so that it's
96 degrees from the steerer tube? Also, does flipping it over change the
reach from the tip of the saddle?

I have an engineering degree, but I'd just flip the stem and see what
happens. It would probably be quicker :-)

I have a couple of math degrees, and that was going to be my suggestion as
well. it is possible to compute it, but it would be a PITA.

And another approach would be to get a big piece of paper, a ruler and
a protractor and draw it very carefully -- perhaps using a scale of
1cm to 1in or 1:2 to make if needed to fit on the paper.

JT

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

Quoted message said:

David L. Johnson said:

Zog The Undeniable said:

> The Question: How much height to I gain if I flip the stem over so that

it's

Quoted message said:

Quoted message said:

Quoted message said:

> 96 degrees from the steerer tube? Also, does flipping it over change the
> reach from the tip of the saddle?

I have an engineering degree, but I'd just flip the stem and see what
happens. It would probably be quicker :-)

I have a couple of math degrees, and that was going to be my suggestion as
well. it is possible to compute it, but it would be a PITA.

And another approach would be to get a big piece of paper, a ruler and
a protractor and draw it very carefully -- perhaps using a scale of
1cm to 1in or 1:2 to make if needed to fit on the paper.

You can also check out http://www.habcycles.com/fitting.html . Someone's
done all the work for you.
---------------
Alex