University frame-flex testing: surprising results

[Tom Sherman]

"jim beam" wrote:
> ...
> filling tires with water doesn't affect wheel stiffness jobst, so of
> course not!!!...
>
If it is cold enough, the water will affect wheel stiffness!

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

 

[Chalo]

Tom Sherman wrote:
>
> jim beam wrote:
> > ...
> > filling tires with water doesn't affect wheel stiffness jobst, so of
> > course not!!!...
>
> If it is cold enough, the water will affect wheel stiffness!

You mean as cold as "Holstein-Freezeland Bovinia"?

Chalo

 

[John Forrest Tomlinson]

On Thu, 17 Jan 2008 21:36:51 -0700, [email protected] wrote:

>On Thu, 17 Jan 2008 18:40:44 -0500, John Forrest Tomlinson
><[email protected]> wrote:
>
>>On Wed, 16 Jan 2008 12:32:51 -0700, [email protected] wrote:
>>
>>>On Wed, 16 Jan 2008 10:32:04 -0800 (PST), Thomas Hood
>>><[email protected]> wrote:
>>>
>>>>http://materials.open.ac.uk/bikeframes/bikeframe.htm
>>>>
>>>>Thomas Hood
>>>
>>>Dear Thomas,
>>>
>>>As usual, the measured flex was undetectable by any rider.
>>
>>I'm having trouble finding where it says this.
>
>Dear John,
>
>That's because I said that the measured flex was undetectable by any
>rider, not the report.

I see, the way you wrote earler sounded like they tested rider
perceptions.

 

[It's Chris]

Only thing I found suprising is how picky some cyclists can be. The
results on all the frames showed a deflrction of 1.3 and 2.7 mm. A total
varience of 1.4 millmeters (insert Ben Stein's "wow" here).

One thing I remember from high school science is that, within reason, a
spring is one of the most efficient means of storing kinetic energy, and
the subsequent release of that stored energy, with a minimum of loss.

1.4 millimeters sounds pretty reasonable to me.

- -
Compliments of:
"Your Friendly Neighborhood Wheelman"

If you want to E-mail me use:
ChrisZCorner "at" webtv "dot" net

My website:
http://geocities.com/czcorner

 

[Thomas Hood]

On 17 Jan, 23:29, "[email protected]"
<[email protected]> wrote:
> > If you had to purchase a handlebar now, you would not be able to
> > purchase a steel handlebar.
>
> http://www.yellowjersey.org/nitto.html
>

If you had arms like an ape, perhaps, but these aren't much use to
your average road cyclist

Tom

 

[M-gineering]

It's Chris wrote:
> Only thing I found suprising is how picky some cyclists can be. The
> results on all the frames showed a deflrction of 1.3 and 2.7 mm. A total
> varience of 1.4 millmeters (insert Ben Stein's "wow" here).
>


I think you need some coffee. Those figures show that the one frame was
more than two times as stiff as the other!


--
/Marten (never could make much from sidestiffness, torsional stiffness
is where it's at imho)

info(apestaartje)m-gineering(punt)nl

 

[Thomas Hood]

On 17 Jan, 22:33, [email protected] wrote:
> Thomas Hood writes:
> > If you had to purchase a handlebar now, you would not be able to
> > purchase a steel handlebar. Given this constraint, is the 31.8 mm
> > oversize standard (http://tinyurl.com/28a8up) better from a
> > durability point of view?
>
> That's not germane, the pint is that I achieved a great improvement in
> rigidity, one that was entirely the quill stem replacement.

I understand the point about the stem, I was just using it as a segway
to a question about handlebars. My question still stands.

> >> Another parameter I find interesting is the distance between front
> >> axle and BB when braking hard. Much of that change occurs in the
> >> the fork steertube and hardly any in bending the downtube.
> >> Rigidity in this mode improves rider confidence in descending
> >> because front wheel speed is consistent with the bicycle.
<snip>
> > Would a 1-1/8" steertube not have been a better choice on your bike,
> > or was this all that was available in 19xx ? Would you build a bike
> > your size of the now standard steel tubeset dimensions: (34.9mm HT,
> > 31.8mm DT, 28.6mm TT & ST)
>
> I don't need not steenkin fat tube. Mine works well enough as I brake
> hard enough to raise the rear wheel on my long wheelbase bicycle.
>
To paraphrase, you stated: 'rigidity in the steertube improves rider
confidence decending.'

So, assuming a choice between the two (weighing the same) would you
still prefer a 1" steertube?

Both these questions relate to the fact that 1" handlebars/stems and
steerers/heasets are becoming increasingly rare. You have often stated
a preference for 1" steerers and tacitly 1" handlebars.

Are their disadvantages to 1-1/8" steerers and handlebars you haven't
mentioned? It seems perverse to favour 1" otherwise.

Thanks,

Thomas Hood

 

[Sandy]

Dans le message de
news:18562e37-5236-4800-9bcc-355e3b2a2ecf@d21g2000prf.googlegroups.com,
Thomas Hood <[email protected]> a réfléchi, et puis a déclaré :
> On 17 Jan, 22:33, [email protected] wrote:
>> Thomas Hood writes:
>>> If you had to purchase a handlebar now, you would not be able to
>>> purchase a steel handlebar. Given this constraint, is the 31.8 mm
>>> oversize standard (http://tinyurl.com/28a8up) better from a
>>> durability point of view?
>>
>> That's not germane, the pint is that I achieved a great improvement
>> in rigidity, one that was entirely the quill stem replacement.
>
> I understand the point about the stem, I was just using it as a segway
> to a question about handlebars. My question still stands.
>
>>>> Another parameter I find interesting is the distance between front
>>>> axle and BB when braking hard. Much of that change occurs in the
>>>> the fork steertube and hardly any in bending the downtube.
>>>> Rigidity in this mode improves rider confidence in descending
>>>> because front wheel speed is consistent with the bicycle.
> <snip>
>>> Would a 1-1/8" steertube not have been a better choice on your bike,
>>> or was this all that was available in 19xx ? Would you build a bike
>>> your size of the now standard steel tubeset dimensions: (34.9mm HT,
>>> 31.8mm DT, 28.6mm TT & ST)
>>
>> I don't need not steenkin fat tube. Mine works well enough as I
>> brake hard enough to raise the rear wheel on my long wheelbase
>> bicycle.
>>
> To paraphrase, you stated: 'rigidity in the steertube improves rider
> confidence decending.'
>
> So, assuming a choice between the two (weighing the same) would you
> still prefer a 1" steertube?
>
> Both these questions relate to the fact that 1" handlebars/stems and
> steerers/heasets are becoming increasingly rare. You have often stated
> a preference for 1" steerers and tacitly 1" handlebars.
>
> Are their disadvantages to 1-1/8" steerers and handlebars you haven't
> mentioned? It seems perverse to favour 1" otherwise.
>
> Thanks,
>
> Thomas Hood

I presume you have found headtubes of 1" that accommodate fork shafts of 1
1/8". I wonder what sort of headset capably supports this arrangement.

On the other hand, headset reducers exist for 1 1/8" headtubes to hold 1"
fork shafts, but I don't think they are thought of as especially stable.

Where did I miss your point?
--
Bonne route !

Sandy
Verneuil-sur-Seine FR

 

[[email protected]]

Thomas Hood writes:

>>> If you had to purchase a handlebar now, you would not be able to
>>> purchase a steel handlebar. Given this constraint, is the 31.8 mm
>>> oversize standard :

http://tinyurl.com/28a8up

>>> better from a durability point of view?

>> That's not germane, the point is that I achieved a great
>> improvement in rigidity, one that was entirely the quill stem
>> replacement.

> I understand the point about the stem, I was just using it as a
> Segway to a question about handlebars. My question still stands.

So what is not durable about my steertube? If there were a problem I
would be interested, but I don't get frozen quill stem syndrome any
longer and I don't need the stupid long head adjustment wrenches any
more. Since switching to swiveling head bearings (Shimano) I haven't
had dimples in the races (indexed steering) from fretting damage.

>>>> Another parameter I find interesting is the distance between
>>>> front axle and BB when braking hard. Much of that change occurs
>>>> in the the fork steertube and hardly any in bending the downtube.
>>>> Rigidity in this mode improves rider confidence in descending
>>>> because front wheel speed is consistent with the bicycle.

>>> Would a 1-1/8" steertube not have been a better choice on your
>>> bike, or was this all that was available in 19xx ? Would you
>>> build a bike your size of the now standard steel tubeset
>>> dimensions: (34.9mm HT, 31.8mm DT, 28.6mm TT & ST)

>> I don't need not steenkin fat tube. Mine works well enough as I
>> brake hard enough to raise the rear wheel on my long wheelbase
>> bicycle.

> To paraphrase, you stated: 'rigidity in the steertube improves rider
> confidence descending.'

I don't have any complaints in that consideration, but I see riders
that do. The same goes for shimmy. It doesn't do that unless I make
a point of letting it do so while riding no-hands at higher speed.

> So, assuming a choice between the two (weighing the same) would you
> still prefer a 1" steertube?

I would have to try a similar bicycle to see if anything changed to my
benefit before switching. If these head bearings were no longer made,
I would prefer to switch.

> Both these questions relate to the fact that 1" handlebars/stems and
> steerers/heasets are becoming increasingly rare. You have often
> stated a preference for 1" steerers and tacitly 1" handlebars.

Bars last a long time and are not a wear item as bar tape is. I think
my head bearings will last a long time as well.

> Are their disadvantages to 1-1/8" steerers and handlebars you
> haven't mentioned? It seems perverse to favour 1" otherwise.

That is not what I said. I don't gratuitously get a new bicycle to
keep up with fashion. That is why I prefer to stay with the equipment
I have unless I can see advantage in changing.

Jobst Brandt

 

[Bill Sornson]

Thomas Hood wrote:

> I understand the point about the stem, I was just using it as a segway
> to a question about handlebars.
> ^^^^^^^

Too lazy to walk?

 

[Tom Nakashima]

<[email protected]> wrote in message
news:[email protected]...
>
> Since switching to swiveling head bearings (Shimano) I haven't
> had dimples in the races (indexed steering) from fretting damage.
> Jobst Brandt

On the subject dimpling with ball bearings in headsets, will small diameter
balls prolong the races?
I know I need to switch over to the swiveling head bearings someday.
-tom

 

[[email protected]]

Tom Nakashima writes:

>> Since switching to swiveling head bearings (Shimano) I haven't had
>> dimples in the races (indexed steering) from fretting damage.

> On the subject dimpling with ball bearings in headsets, will small
> diameter balls prolong the races? I know I need to switch over to
> the swiveling head bearings someday.

I don't know which effect is greater, contact pressure or ball
rotation. However, larger bearing balls have usually been the better
course even though the number of balls for a given circle decreases
with increasing ball size. I'm still using the angular contact
pre-loaded cartridge bearings I had before converting to threadless.
That required boring out the threads and putting a conical seat in the
upper bearing mount to receive the centering cone. It looks like a
typical threaded head bearing.

Jobst Brandt

 

[Tom Nakashima]

<[email protected]> wrote in message
news:[email protected]...
> Tom Nakashima writes:
>
>>> Since switching to swiveling head bearings (Shimano) I haven't had
>>> dimples in the races (indexed steering) from fretting damage.
>
>> On the subject dimpling with ball bearings in headsets, will small
>> diameter balls prolong the races? I know I need to switch over to
>> the swiveling head bearings someday.
>
> I don't know which effect is greater, contact pressure or ball
> rotation. However, larger bearing balls have usually been the better
> course even though the number of balls for a given circle decreases
> with increasing ball size. I'm still using the angular contact
> pre-loaded cartridge bearings I had before converting to threadless.
> That required boring out the threads and putting a conical seat in the
> upper bearing mount to receive the centering cone. It looks like a
> typical threaded head bearing.
>
> Jobst Brandt

I remember you telling me this, but was meaning to ask you about the
conical cone angle, how did you get the right conical cone angle in the
seat?
Or is angle not critical?
Also aren't the seats hardened?
-tom

 

[[email protected]]

Tom Nakashima writes:

>>>> Since switching to swiveling head bearings (Shimano) I haven't
>>>> had dimples in the races (indexed steering) from fretting damage.

>>> On the subject dimpling with ball bearings in headsets, will small
>>> diameter balls prolong the races? I know I need to switch over to
>>> the swiveling head bearings someday.

>> I don't know which effect is greater, contact pressure or ball
>> rotation. However, larger bearing balls have usually been the
>> better course even though the number of balls for a given circle
>> decreases with increasing ball size. I'm still using the angular
>> contact pre-loaded cartridge bearings I had before converting to
>> threadless. That required boring out the threads and putting a
>> conical seat in the upper bearing mount to receive the centering
>> cone. It looks like a typical threaded head bearing.

> I remember you telling me this, but was meaning to ask you about the
> conical cone angle, how did you get the right conical cone angle in
> the seat? Or is angle not critical? Also aren't the seats
> hardened?

No hardening, all parts are aluminum. The centering cone is a one
slot split ring with a 60° angle so that when it is pushed in axially,
it clamps the steertube and centers the upper bearing cup. I
saw no reason to buy a new head-set and had my old one modified.

http://en.wikipedia.org/wiki/Image:Threadless-bicycle-headset.jpg

Jobst Brandt

 

[Tom Nakashima]

<[email protected]> wrote in message
news:[email protected]...
Tom Nakashima writes:

>>>> Since switching to swiveling head bearings (Shimano) I haven't
>>>> had dimples in the races (indexed steering) from fretting damage.

>>> On the subject dimpling with ball bearings in headsets, will small
>>> diameter balls prolong the races? I know I need to switch over to
>>> the swiveling head bearings someday.

>> I don't know which effect is greater, contact pressure or ball
>> rotation. However, larger bearing balls have usually been the
>> better course even though the number of balls for a given circle
>> decreases with increasing ball size. I'm still using the angular
>> contact pre-loaded cartridge bearings I had before converting to
>> threadless. That required boring out the threads and putting a
>> conical seat in the upper bearing mount to receive the centering
>> cone. It looks like a typical threaded head bearing.

> I remember you telling me this, but was meaning to ask you about the
> conical cone angle, how did you get the right conical cone angle in
> the seat? Or is angle not critical? Also aren't the seats
> hardened?

>>No hardening, all parts are aluminum. The centering cone is a one
slot split ring with a 60° angle so that when it is pushed in axially,
it clamps the steertube and centers the upper bearing cup. I
saw no reason to buy a new head-set and had my old one modified.

http://en.wikipedia.org/wiki/Image:Threadless-bicycle-headset.jpg

>>Jobst Brandt

Thanks for the link and the description, I can see it now.
As for the steering column, Dale Saso recommended cutting the original
and brazing a short tube to fit over, and then adding a 1.00" dia. tube to
extend. Making an extension to the steering column to accommodate swiveling
bearing headset instad of just brazing on a whole new steering column.
Your comments on the extension?
-tom

 

[[email protected]]

Tom Nakashima writes:

>>>>> Since switching to swiveling head bearings (Shimano) I haven't
>>>>> had dimples in the races (indexed steering) from fretting
>>>>> damage.

>>>> On the subject dimpling with ball bearings in headsets, will
>>>> small diameter balls prolong the races? I know I need to switch
>>>> over to the swiveling head bearings someday.

>>> I don't know which effect is greater, contact pressure or ball
>>> rotation. However, larger bearing balls have usually been the
>>> better course even though the number of balls for a given circle
>>> decreases with increasing ball size. I'm still using the angular
>>> contact pre-loaded cartridge bearings I had before converting to
>>> threadless. That required boring out the threads and putting a
>>> conical seat in the upper bearing mount to receive the centering
>>> cone. It looks like a typical threaded head bearing.

>> I remember you telling me this, but was meaning to ask you about
>> the conical cone angle, how did you get the right conical cone
>> angle in the seat? Or is angle not critical? Also aren't the
>> seats hardened?

> No hardening, all parts are aluminum. The centering cone is a one
> slot split ring with a 60? angle so that when it is pushed in
> axially, it clamps the steertube and centers the upper bearing cup.
> I saw no reason to buy a new head-set and had my old one modified.

http://en.wikipedia.org/wiki/Image:Threadless-bicycle-headset.jpg

> Thanks for the link and the description, I can see it now. As for
> the steering column, Dale Saso recommended cutting the original and
> brazing a short tube to fit over, and then adding a 1.00" dia. tube
> to extend. Making an extension to the steering column to
> accommodate swiveling bearing headset instead of just brazing on a
> whole new steering column. Your comments on the extension?

I got a new fork, mine being many miles old. I'm sure there are
various good ways of extending the steertube and I'd leave that up to
the frame builder. I meet riders who have had this done so it isn't
uncommon. I have an aluminum spacer tube to get my stem height the
same as before. Be careful and after being sure what fits best cut
the steertube to length.

You'll like adjusting head bearing with an Allen wrench, removing the
bars without untaping and removing a brake lever, removing the stem
without a hammer and the solid support. For me it was also getting
rid of corrosion stuck stems.

Jobst Brandt

 

[Tom Nakashima]

<[email protected]> wrote in message
news:[email protected]...
> Tom Nakashima writes:
>
>>>>>> Since switching to swiveling head bearings (Shimano) I haven't
>>>>>> had dimples in the races (indexed steering) from fretting
>>>>>> damage.
>
>>>>> On the subject dimpling with ball bearings in headsets, will
>>>>> small diameter balls prolong the races? I know I need to switch
>>>>> over to the swiveling head bearings someday.
>
>>>> I don't know which effect is greater, contact pressure or ball
>>>> rotation. However, larger bearing balls have usually been the
>>>> better course even though the number of balls for a given circle
>>>> decreases with increasing ball size. I'm still using the angular
>>>> contact pre-loaded cartridge bearings I had before converting to
>>>> threadless. That required boring out the threads and putting a
>>>> conical seat in the upper bearing mount to receive the centering
>>>> cone. It looks like a typical threaded head bearing.
>
>>> I remember you telling me this, but was meaning to ask you about
>>> the conical cone angle, how did you get the right conical cone
>>> angle in the seat? Or is angle not critical? Also aren't the
>>> seats hardened?
>
>> No hardening, all parts are aluminum. The centering cone is a one
>> slot split ring with a 60? angle so that when it is pushed in
>> axially, it clamps the steertube and centers the upper bearing cup.
>> I saw no reason to buy a new head-set and had my old one modified.
>
> http://en.wikipedia.org/wiki/Image:Threadless-bicycle-headset.jpg
>
>> Thanks for the link and the description, I can see it now. As for
>> the steering column, Dale Saso recommended cutting the original and
>> brazing a short tube to fit over, and then adding a 1.00" dia. tube
>> to extend. Making an extension to the steering column to
>> accommodate swiveling bearing headset instead of just brazing on a
>> whole new steering column. Your comments on the extension?
>
> I got a new fork, mine being many miles old. I'm sure there are
> various good ways of extending the steertube and I'd leave that up to
> the frame builder. I meet riders who have had this done so it isn't
> uncommon. I have an aluminum spacer tube to get my stem height the
> same as before. Be careful and after being sure what fits best cut
> the steertube to length.
>
> You'll like adjusting head bearing with an Allen wrench, removing the
> bars without untaping and removing a brake lever, removing the stem
> without a hammer and the solid support. For me it was also getting
> rid of corrosion stuck stems.
>
> Jobst Brandt

I know, you already sold me on it last time...I just have to get it done.
Actually I'm going to call Saso to see when he can pencil me in.
My fork is still good, so I'll go with the extension, hanks for reminding
me on the height.
-tom

 

[A Muzi]

-snip frame flex-
Sandy wrote:
> On the other hand, headset reducers exist for 1 1/8" headtubes to hold 1"
> fork shafts, but I don't think they are thought of as especially stable.

Think of it as a thick headset cup; No technical reason not to and no
problems with them at all. Useful especially on new touring bikes where
a threaded fork tall and easily changed stem height is desired.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[Tom Sherman]

Chalo Colina wrote:
> Tom Sherman wrote:
>> jim beam wrote:
>>> ...
>>> filling tires with water doesn't affect wheel stiffness jobst, so of
>>> course not!!!...
>> If it is cold enough, the water will affect wheel stiffness!
>
> You mean as cold as "Holstein-Freezeland Bovinia"?
>
Well, the water would not stay in a liquid form for long around here
right now.

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

 

[Tom Sherman]

Thomas Hood wrote:
> On 17 Jan, 23:29, "[email protected]"
> <[email protected]> wrote:
>>> If you had to purchase a handlebar now, you would not be able to
>>> purchase a steel handlebar.
>> http://www.yellowjersey.org/nitto.html
>>
>
> If you had arms like an ape, perhaps, but these aren't much use to
> your average road cyclist
>
Except for the odd circus bear, all cyclists ARE apes.

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth