Single-Bolt Seatpost saddle slippage? [Archive]

* * Chas

01-04-1970, 11:50 AM

"Andrew F Martin" <andrew.franklin.martin@gmail.com> wrote in message
news:bfedd0e4-5fa0-4896-9f52-f67fb8ca5520@d19g2000prm.googlegroups.com...
> I've got a Madone with the Bontrager single-bolt Seat Mast. 3 straight
> races I've hit a bump and had the saddle nose drop significantly.
> Anybody else have this problem with a single-bolt design? I'm 180 and
> do tent to slide forward to the nose of the saddle (Arione) when I'm
> digging hard.
>
> My shop said to try carbon prep, and it seems a lot stickier, but
> setting up the angle was a pain. Any alternatives? Anybody know of
> an aftermarket Madone Seat Mast with a traditional 2-bolt design?

Most single bolt seatpost suck! The ones with the serrations are difficult
to make minor adjustments and the other style tend to slip. There are
several dual bolt seatposts on the market with front/back adjustments. The
ones with one bolt one each side of the seatpost are rather useless for
making fine adjustments.

Chas.

jobst.brandt@stanfordalumni.org

01-04-1970, 11:50 AM

Andrew F Martin wrote:

> I've got a Madone with the Bontrager single-bolt Seat Mast. 3
> straight races I've hit a bump and had the saddle nose drop
> significantly. Anybody else have this problem with a single-bolt
> design? I'm 180 and do tent to slide forward to the nose of the
> saddle (Arione) when I'm digging hard.

> My shop said to try carbon prep, and it seems a lot stickier, but
> setting up the angle was a pain. Any alternatives? Anybody know of
> an aftermarket Madone Seat Mast with a traditional 2-bolt design?

A point one shouldn't overlook is failure consequences as with bar
stems on threadless steertubes. They need TWO clamp bolts on the
steertube and FOUR on the handlebar clamp so that a single bolt
failure will not leave the rider with no bars attached to the bicycle
in the middle of a high stress sprint.

The same goes for seat post saddle clamps. If the single bolt fails,
the rider falls onto the rotating rear wheel to produce an involuntary
colostomy. This occurred locally and the outcome was a shock to
riders who heard of it and caused review of the matter of light
weight.

Jobst Brandt

smokey

01-04-1970, 11:50 AM

On Jun 9, 10:47*pm, Andrew F Martin <andrew.franklin.mar...@gmail.com>
wrote:
> I've got a Madone with the Bontrager single-bolt Seat Mast. 3 straight
> races I've hit a bump and had the saddle nose drop significantly.
> Anybody else have this problem with a single-bolt design? *I'm 180 and
> do tent to slide forward to the nose of the saddle (Arione) when I'm
> digging hard.
>
> My shop said to try carbon prep, and it seems a lot stickier, but
> setting up the angle was a pain. *Any alternatives? *Anybody know of
> an aftermarket Madone Seat Mast with a traditional 2-bolt design?

One thing that I've used successfully on slipping metal parts is
automotive valve lapping compound. It stopped the metal post from
slipping down in my steel framed Lemond. It might also work on your
seat post head. It can be found at any auto parts store.

Smokey

bjw@mambo.ucolick.org

01-04-1970, 11:52 AM

On Jun 10, 9:26*am, "* * Chas" <verktygj...@aol.spamski.com> wrote:
> "Andrew F Martin" <andrew.franklin.mar...@gmail.com> wrote in messagenews:bfedd0e4-5fa0-4896-9f52-f67fb8ca5520@d19g2000prm.googlegroups.com...
>
> > I've got a Madone with the Bontrager single-bolt Seat Mast. 3 straight
> > races I've hit a bump and had the saddle nose drop significantly.
> > Anybody else have this problem with a single-bolt design? *I'm 180 and
> > do tent to slide forward to the nose of the saddle (Arione) when I'm
> > digging hard.
>
> > My shop said to try carbon prep, and it seems a lot stickier, but
> > setting up the angle was a pain. *Any alternatives? *Anybody know of
> > an aftermarket Madone Seat Mast with a traditional 2-bolt design?
>
> Most single bolt seatpost suck! The ones with the serrations are difficult
> to make minor adjustments and the other style tend to slip. There are
> several dual bolt seatposts on the market with front/back adjustments. The
> ones with one bolt one each side of the seatpost are rather useless for
> making fine adjustments.

Yes, but. The OP has a Trek Madone, a machine suitable
for the most discerning of riders who require the ultimate in
aerodynamics. Especially if they've already got a fully
streamlined aerobelly. As such, once you get above a certain
level of Madone (5.1 or Gold Elite or Platinum Preferred Traveler
or something like that) it has an "aero" seatmast that doesn't
take a standard seatpost, as far as I can tell.

And people say there is no such thing as progress!

Ben

Tom Kunich

01-04-1970, 11:54 AM

<jobst.brandt@stanfordalumni.org> wrote in message
news:484ed7fd$0$17235$742ec2ed@news.sonic.net...
>
> A point one shouldn't overlook is failure consequences as with bar
> stems on threadless steertubes. They need TWO clamp bolts on the
> steertube and FOUR on the handlebar clamp so that a single bolt
> failure will not leave the rider with no bars attached to the bicycle
> in the middle of a high stress sprint.
>
> The same goes for seat post saddle clamps. If the single bolt fails,
> the rider falls onto the rotating rear wheel to produce an involuntary
> colostomy. This occurred locally and the outcome was a shock to
> riders who heard of it and caused review of the matter of light
> weight.

I'd like to underscore Jobst's statements here since I came very close to a
serious injury less than a month ago due to something as silly as a clipless
pedal cleat having a funny wear pattern so that it gradually got so that it
disconnected with the slightest inward turn of the heal.

I'll eventually be as good as new according to several doctors but I'd
rather have never had such an accident.

John Forrest Tomlinson

01-04-1970, 11:54 AM

On 10 Jun 2008 19:37:33 GMT, jobst.brandt@stanfordalumni.org wrote:

>The same goes for seat post saddle clamps. If the single bolt fails,
>the rider falls onto the rotating rear wheel to produce an involuntary
>colostomy.

For sure that's a potentially dangerous situation, but not quite as
definitely dangerous as you say. I've had it happen twice -- around
1992 and around 2002 and neither time did I hurt myself.

But yeah, reliablity in that area is important. The seatposts on my
bikes are now single bolt, but sturdier (I hope). At least the bolts
are bigger.

jobst.brandt@stanfordalumni.org

01-04-1970, 11:55 AM

John Forrest Tomlinson wrote:

>> The same goes for seat post saddle clamps. If the single bolt
>> fails, the rider falls onto the rotating rear wheel to produce an
>> involuntary colostomy.

> For sure that's a potentially dangerous situation, but not quite as
> definitely dangerous as you say. I've had it happen twice -- around
> 1992 and around 2002 and neither time did I hurt myself.

> But yeah, reliability in that area is important. The seatposts on
> my bikes are now single bolt, but sturdier (I hope). At least the
> bolts are bigger.

That depends on how clever the design is. Old Schwinn balloon tired
bicycles had single bolt clamps that with bolt failure the saddle
could not fall away from under the rider as the current light weight
designs "racing" do. Old Campagnolo Record posts had two bolts with
which two bridge clamps allowed fore and aft sliding and by
differential tightening adjust the fore and aft tilt.

This attachment was reduced to a single bolt by others at a later date
without anyone questioning its safety and failure mode. I suspect
these posts are the ones under discussion.

Jobst Brandt

John Forrest Tomlinson

01-04-1970, 11:55 AM

On 11 Jun 2008 00:09:03 GMT, jobst.brandt@stanfordalumni.org wrote:

>John Forrest Tomlinson wrote:
>
>>> The same goes for seat post saddle clamps. If the single bolt
>>> fails, the rider falls onto the rotating rear wheel to produce an
>>> involuntary colostomy.
>
>> For sure that's a potentially dangerous situation, but not quite as
>> definitely dangerous as you say. I've had it happen twice -- around
>> 1992 and around 2002 and neither time did I hurt myself.
>
>> But yeah, reliability in that area is important. The seatposts on
>> my bikes are now single bolt, but sturdier (I hope). At least the
>> bolts are bigger.
>
>That depends on how clever the design is.

If the degree of danger if the bolt breaks varies with different
designs, I don't understand why you say "the rider falls" as if that
is a consistent outcome.

JT

jobst.brandt@stanfordalumni.org

01-04-1970, 11:55 AM

John Forrest Tomlinson wrote:

>>>> The same goes for seat post saddle clamps. If the single bolt
>>>> fails, the rider falls onto the rotating rear wheel to produce an
>>>> involuntary colostomy.

>>> For sure that's a potentially dangerous situation, but not quite
>>> as definitely dangerous as you say. I've had it happen twice --
>>> around 1992 and around 2002 and neither time did I hurt myself.

>>> But yeah, reliability in that area is important. The seatposts on
>>> my bikes are now single bolt, but sturdier (I hope). At least the
>>> bolts are bigger.

>> That depends on how clever the design is. Old Schwinn balloon
>> tired bicycles had single bolt clamps that with bolt failure the
>> saddle could not fall away from under the rider as the current
>> light weight designs "racing" do. Old Campagnolo Record posts had
>> two bolts with which two bridge clamps allowed fore and aft sliding
>> and by differential tightening adjust the fore and aft tilt.

>> This attachment was reduced to a single bolt by others at a later
>> date without anyone questioning its safety and failure mode. I
>> suspect these posts are the ones under discussion.

> If the degree of danger if the bolt breaks varies with different
> designs, I don't understand why you say "the rider falls" as if that
> is a consistent outcome.

You can only seriously say that having deleted what I had written and
reinserted. I explained why the single bolt is hazardous and the
difference between a heavy Schwinn attachment and a pseudo Campagnolo
attachment that uses a single bolt the original size. I included the
disclaimer: "I suspect these posts are the ones under discussion."

From your comment I'm not convinced you are posting in good faith.
Your question was anticipated and previously answered.

Jobst Brandt

John Forrest Tomlinson

01-04-1970, 11:55 AM

On 11 Jun 2008 00:47:55 GMT, jobst.brandt@stanfordalumni.org wrote:

>John Forrest Tomlinson wrote:
>
>>>>> The same goes for seat post saddle clamps. If the single bolt
>>>>> fails, the rider falls onto the rotating rear wheel to produce an
>>>>> involuntary colostomy.
>

>> If the degree of danger if the bolt breaks varies with different
>> designs, I don't understand why you say "the rider falls" as if that
>> is a consistent outcome.
>
>You can only seriously say that having deleted what I had written and
>reinserted. I explained why the single bolt is hazardous and the
>difference between a heavy Schwinn attachment and a pseudo Campagnolo
>attachment that uses a single bolt the original size. I included the
>disclaimer: "I suspect these posts are the ones under discussion."
>
>From your comment I'm not convinced you are posting in good faith.
>Your question was anticipated and previously answered.

Here is what you wrote earlier:

> That depends on how clever the design is. Old Schwinn balloon tired
> bicycles had single bolt clamps that with bolt failure the saddle
> could not fall away from under the rider as the current light weight
> designs "racing" do. Old Campagnolo Record posts had two bolts with
> which two bridge clamps allowed fore and aft sliding and by
> differential tightening adjust the fore and aft tilt.

You wrote "that depends on the design" after saying that "If the
single bolt fails, the rider falls onto the rotating rear wheel"

Again, you made a definitive and comprehensive statement, and then
qualified it to apply to only some situations and not others. The
earlier statement was simply wrong in trying to be comprehensive.
That's all I'm saying and I'm saying it in quite good faith. And
laughing.

jim beam

01-04-1970, 11:55 AM

jobst.brandt@stanfordalumni.org wrote:
> John Forrest Tomlinson wrote:
>
>>>>> The same goes for seat post saddle clamps. If the single bolt
>>>>> fails, the rider falls onto the rotating rear wheel to produce an
>>>>> involuntary colostomy.
>
>>>> For sure that's a potentially dangerous situation, but not quite
>>>> as definitely dangerous as you say. I've had it happen twice --
>>>> around 1992 and around 2002 and neither time did I hurt myself.
>
>>>> But yeah, reliability in that area is important. The seatposts on
>>>> my bikes are now single bolt, but sturdier (I hope). At least the
>>>> bolts are bigger.
>
>>> That depends on how clever the design is. Old Schwinn balloon
>>> tired bicycles had single bolt clamps that with bolt failure the
>>> saddle could not fall away from under the rider as the current
>>> light weight designs "racing" do. Old Campagnolo Record posts had
>>> two bolts with which two bridge clamps allowed fore and aft sliding
>>> and by differential tightening adjust the fore and aft tilt.
>
>>> This attachment was reduced to a single bolt by others at a later
>>> date without anyone questioning its safety and failure mode. I
>>> suspect these posts are the ones under discussion.
>
>> If the degree of danger if the bolt breaks varies with different
>> designs, I don't understand why you say "the rider falls" as if that
>> is a consistent outcome.
>
> You can only seriously say that having deleted what I had written and
> reinserted. I explained why the single bolt is hazardous and the
> difference between a heavy Schwinn attachment and a pseudo Campagnolo
> attachment that uses a single bolt the original size. I included the
> disclaimer: "I suspect these posts are the ones under discussion."
>
> From your comment I'm not convinced you are posting in good faith.
> Your question was anticipated and previously answered.

but jobst, you contradict yourself. upstream you say: "the saddle could
not fall away from under the rider as the current light weight designs
"racing" do." well, i've looked at every single one of my "racing" seat
posts, and not a single one will allow the seat to "fall away" in the
event of bolt breakage because the bottom cradle rests in compression on
the post head.

could it possibly be that you're contemplating some dim and distant
memory of some design you once saw and are using that as criticism for
the last 30 years of seat posts? because that would be entirely in
character with some of your other bizarre rants about equipment you
don't own or use.

how many brands do you possess btw? and how old are they? i ask
because every single one of the campy, ritchie, easton, weyless, or
other cheapo nameless brands i possess all have the cradle in
compression against the head.

oh, and on the subject of bolt breakage, the only bending or tensile
load on that bolt is from seat tilting. unless the seat is mounted at
the extreme of one or other end of its rails, there's not much fatigue
load. but you'd see that if you actually possessed a modern seat post.
or could be bothered to look at one.

jobst.brandt@stanfordalumni.org

01-04-1970, 11:56 AM

John Forrest Tomlinson wrote:

>>>>>> The same goes for seat post saddle clamps. If the single bolt
>>>>>> fails, the rider falls onto the rotating rear wheel to produce an
>>>>>> involuntary colostomy.

>>> If the degree of danger if the bolt breaks varies with different
>>> designs, I don't understand why you say "the rider falls" as if that
>>> is a consistent outcome.

>> You can only seriously say that having deleted what I had written and
>> reinserted. I explained why the single bolt is hazardous and the
>> difference between a heavy Schwinn attachment and a pseudo Campagnolo
>> attachment that uses a single bolt the original size. I included the
>> disclaimer: "I suspect these posts are the ones under discussion."

>> From your comment I'm not convinced you are posting in good faith.
>> Your question was anticipated and previously answered.

> Here is what you wrote earlier:

So why did you delete that from this response? As you see, I
reinserted that paragraph and you deleted it once more. You didn't
have to get it from an earlier posting and add it here/
>>

>># That depends on how clever the design is. Old Schwinn balloon
>># tired bicycles had single bolt clamps that with bolt failure the
>># saddle could not fall away from under the rider as the current
>># light weight designs "racing" do. Old Campagnolo Record posts
>># had two bolts with which two bridge clamps allowed fore and aft
>># sliding and by differential tightening adjust the fore and aft
>># tilt.

> You wrote "that depends on the design" after saying that "If the
> single bolt fails, the rider falls onto the rotating rear wheel"

That's why I mentoned old Schwinn design that does not present this
hazard, thereby not making it dependent on one bolt but rather the
design of that one bolt clamp.

> Again, you made a definitive and comprehensive statement, and then
> qualified it to apply to only some situations and not others. The
> earlier statement was simply wrong in trying to be comprehensive.
> That's all I'm saying and I'm saying it in quite good faith. And
> laughing.

You're creating your own entertainment at my expense. The single bolt
seat clamps that are a derivative of the earlier Campagnolo Record
seat post seemed to some to be an advance, but when the single bolt
breaks, the saddle falls backward, the load of the sit bones being
behind the pivot during at least part of the pedal stroke. This is
not apparent to many in the business or its users, so I think it is
worth mentioning the details.

By bolt failure the saddle can drop to the ground and the rider, still
attached to his pedals, land with his rectum on the rotating rear
wheel. I know this from a couple of incidents, so I mentioned it.
The injury was serious but repairable with emergency room sutures.

You needn't defend the single bolt seat post here at my expense. I
think there are better ways of discussing the merits of seat clamps
than with ad hominem argumentation. I explained that these seat posts
ignore the need for redundant bolts similar to stem and bar
attachments, and that the danger is not apparent.

Jobst Brandt

jim beam

01-04-1970, 11:56 AM

jobst.brandt@stanfordalumni.org wrote:
> John Forrest Tomlinson wrote:
>
>>>>>>> The same goes for seat post saddle clamps. If the single bolt
>>>>>>> fails, the rider falls onto the rotating rear wheel to produce an
>>>>>>> involuntary colostomy.
>
>>>> If the degree of danger if the bolt breaks varies with different
>>>> designs, I don't understand why you say "the rider falls" as if that
>>>> is a consistent outcome.
>
>>> You can only seriously say that having deleted what I had written and
>>> reinserted. I explained why the single bolt is hazardous and the
>>> difference between a heavy Schwinn attachment and a pseudo Campagnolo
>>> attachment that uses a single bolt the original size. I included the
>>> disclaimer: "I suspect these posts are the ones under discussion."
>
>>> From your comment I'm not convinced you are posting in good faith.
>>> Your question was anticipated and previously answered.
>
>> Here is what you wrote earlier:
>
> So why did you delete that from this response? As you see, I
> reinserted that paragraph and you deleted it once more. You didn't
> have to get it from an earlier posting and add it here/
>>>
>
>>> # That depends on how clever the design is. Old Schwinn balloon
>>> # tired bicycles had single bolt clamps that with bolt failure the
>>> # saddle could not fall away from under the rider as the current
>>> # light weight designs "racing" do. Old Campagnolo Record posts
>>> # had two bolts with which two bridge clamps allowed fore and aft
>>> # sliding and by differential tightening adjust the fore and aft
>>> # tilt.
>
>> You wrote "that depends on the design" after saying that "If the
>> single bolt fails, the rider falls onto the rotating rear wheel"
>
> That's why I mentoned old Schwinn design that does not present this
> hazard, thereby not making it dependent on one bolt but rather the
> design of that one bolt clamp.
>
>> Again, you made a definitive and comprehensive statement, and then
>> qualified it to apply to only some situations and not others. The
>> earlier statement was simply wrong in trying to be comprehensive.
>> That's all I'm saying and I'm saying it in quite good faith. And
>> laughing.
>
> You're creating your own entertainment at my expense. The single bolt
> seat clamps that are a derivative of the earlier Campagnolo Record
> seat post seemed to some to be an advance, but when the single bolt
> breaks, the saddle falls backward, the load of the sit bones being
> behind the pivot during at least part of the pedal stroke. This is
> not apparent to many in the business or its users, so I think it is
> worth mentioning the details.

"not apparent" is somewhat presumptive given that you attribute it to
all and sundry who may actually have bothered to contemplate such
matters. what's much more "not apparent" however is whether you're
prepared to address this single bolt's loading mode and discuss its real
world failure statistics. observation of manufacturer's torque spec
should enter into your discussion.

>
> By bolt failure the saddle can drop to the ground and the rider, still
> attached to his pedals, land with his rectum on the rotating rear
> wheel.

you repeat [not just here, but have done so many times] this clinical
detail as if it's more important than potential femoral artery rupture
or testicular laceration. do you have some kind of proctological
interest in that particular injury? i mean, it's ok here in the bay
area you know.

> I know this from a couple of incidents, so I mentioned it.
> The injury was serious but repairable with emergency room sutures.
>
> You needn't defend the single bolt seat post here at my expense.

eh? and why say it twice?

> I
> think there are better ways of discussing the merits of seat clamps
> than with ad hominem argumentation.

the only person here getting close to ad hominem is you. jft simply
pointed out that your typically jobstian "definitive and comprehensive
statement" required qualification, and thus was not a "definitive and
comprehensive statement" at all. if you think thats personal attack,
you're losing the plot.

> I explained that these seat posts
> ignore the need for redundant bolts similar to stem and bar
> attachments, and that the danger is not apparent.

how much redundancy do you need jobst? two front forks? two pedal
spindles each side? two crank arms each side? two brake levers each
side? double brake cables front and rear? two seat post tubes? we
gave up on biplanes years ago jobst - you can look for other ogres under
your bed.

John Forrest Tomlinson

01-04-1970, 11:56 AM

On 11 Jun 2008 03:23:14 GMT, jobst.brandt@stanfordalumni.org wrote:

>John Forrest Tomlinson wrote:
>
>>>>>>> The same goes for seat post saddle clamps. If the single bolt
>>>>>>> fails, the rider falls onto the rotating rear wheel to produce an
>>>>>>> involuntary colostomy.
>
>>>> If the degree of danger if the bolt breaks varies with different
>>>> designs, I don't understand why you say "the rider falls" as if that
>>>> is a consistent outcome.
>
>>> You can only seriously say that having deleted what I had written and
>>> reinserted. I explained why the single bolt is hazardous and the
>>> difference between a heavy Schwinn attachment and a pseudo Campagnolo
>>> attachment that uses a single bolt the original size. I included the
>>> disclaimer: "I suspect these posts are the ones under discussion."
>
>>> From your comment I'm not convinced you are posting in good faith.
>>> Your question was anticipated and previously answered.
>
>> Here is what you wrote earlier:
>
>So why did you delete that from this response?

Because it wasn't relevant, but you were trying to make it lool like I
was up to somethign deceptive, which I wasn't. If you want to rag on
my usenet skills, go ahead, but you shouldn't assign motive to those
lack of skills.
> As you see, I
>reinserted that paragraph and you deleted it once more. You didn't
>have to get it from an earlier posting and add it here/
>>>
>
>>># That depends on how clever the design is. Old Schwinn balloon
>>># tired bicycles had single bolt clamps that with bolt failure the
>>># saddle could not fall away from under the rider as the current
>>># light weight designs "racing" do. Old Campagnolo Record posts
>>># had two bolts with which two bridge clamps allowed fore and aft
>>># sliding and by differential tightening adjust the fore and aft
>>># tilt.
>
>> You wrote "that depends on the design" after saying that "If the
>> single bolt fails, the rider falls onto the rotating rear wheel"
>
>That's why I mentoned old Schwinn design that does not present this
>hazard, thereby not making it dependent on one bolt but rather the
>design of that one bolt clamp.
>
>> Again, you made a definitive and comprehensive statement, and then
>> qualified it to apply to only some situations and not others. The
>> earlier statement was simply wrong in trying to be comprehensive.
>> That's all I'm saying and I'm saying it in quite good faith. And
>> laughing.
>
>You're creating your own entertainment at my expense.

Yes. The entertainment is that I point out a tiny inconsistency in
what you wrote, and you use the occasssion to suggest I was posting
"in bad faith." If by bad faith you mean trying to be deceptive,
you're wrong. The only "bad faith" is some small enjoyment is
pointing out a tiny error on your part. So I enjoy that? So what?

The single bolt
>seat clamps that are a derivative of the earlier Campagnolo Record
>seat post seemed to some to be an advance, but when the single bolt
>breaks, the saddle falls backward, the load of the sit bones being
>behind the pivot during at least part of the pedal stroke. This is
>not apparent to many in the business or its users, so I think it is
>worth mentioning the details.
>
>By bolt failure the saddle can drop to the ground and the rider, still
>attached to his pedals, land with his rectum on the rotating rear
>wheel. I know this from a couple of incidents, so I mentioned it.
>The injury was serious but repairable with emergency room sutures.
>
>You needn't defend the single bolt seat post here at my expense. I
>think there are better ways of discussing the merits of seat clamps
>than with ad hominem argumentation. I explained that these seat posts
>ignore the need for redundant bolts similar to stem and bar
>attachments, and that the danger is not apparent.

I'm not knowledgeable enough about engineering to comment on all of
the above, so I won't even try. I'm not even discussing the merits of
seatposts. I was simply pointing out that a bolt breaking doesn't
necessarily result in injury -- which you said it did, at first,
without qualification. If you want to try to disparage my statement
in some way to preserve your ego or make me look foolish, go ahead.
If I were in your situation, I'd simply let it go.

01-04-1970, 11:56 AM

I had a one bolt Campy for a long time. I would tighten it very hard
and it would still eventually slip. The original Avocet design was
perfect, and I was lucky to find a Suntour Superb in 27.0. I'd love a
Nitto Jaguar, but I'd have to be drunk to PayPal that kind of money.
I've never understood why two bolts is not universal. You keep the
angle and move the seat backward and forward by loosening and
retightening only one bolt, or keep the displacement the same and only
change the angle by loosening one bolt as you tighten the other.
Brilliant!

JG

jim beam

01-04-1970, 11:56 AM

JG wrote:
> I had a one bolt Campy for a long time. I would tighten it very hard
> and it would still eventually slip. The original Avocet design was
> perfect, and I was lucky to find a Suntour Superb in 27.0. I'd love a
> Nitto Jaguar, but I'd have to be drunk to PayPal that kind of money.
> I've never understood why two bolts is not universal. You keep the
> angle and move the seat backward and forward by loosening and
> retightening only one bolt, or keep the displacement the same and only
> change the angle by loosening one bolt as you tighten the other.
> Brilliant!

not really. if one bolt breaks, the remainder of the cradle is
unbalanced and fails under trivial load. pointless really, especially
for a system where tilt load is the main fatigue factor. much better to
have a single bolt at what would effectively be the "neutral plane".

* * Chas

01-04-1970, 11:56 AM

"JG" <jchg@cox.net> wrote in message
news:55a3f601-2730-4ea3-98e8-818ce6bcd053@z16g2000prn.googlegroups.com...
> I had a one bolt Campy for a long time. I would tighten it very hard
> and it would still eventually slip. The original Avocet design was
> perfect, and I was lucky to find a Suntour Superb in 27.0. I'd love a
> Nitto Jaguar, but I'd have to be drunk to PayPal that kind of money.
> I've never understood why two bolts is not universal. You keep the
> angle and move the seat backward and forward by loosening and
> retightening only one bolt, or keep the displacement the same and only
> change the angle by loosening one bolt as you tighten the other.
> Brilliant!
>
> JG

Back in the day there were a lot of complaints about mounting seats and
adjusting them with Campy 2 bolt style seatposts (and similar knockoffs).
It was partly due to not having a proper fitting 10mm wrench to get to the
bolt heads. The Avocet and similar 2 bolt seatposts that used socket head
cap screws accessible from the bottom was a great solution.

I've switched most of my bikes back to 2 bolt Campy seatposts.

Chas.

jim beam

01-04-1970, 11:56 AM

* * Chas wrote:
> "JG" <jchg@cox.net> wrote in message
> news:55a3f601-2730-4ea3-98e8-818ce6bcd053@z16g2000prn.googlegroups.com...
>> I had a one bolt Campy for a long time. I would tighten it very hard
>> and it would still eventually slip. The original Avocet design was
>> perfect, and I was lucky to find a Suntour Superb in 27.0. I'd love a
>> Nitto Jaguar, but I'd have to be drunk to PayPal that kind of money.
>> I've never understood why two bolts is not universal. You keep the
>> angle and move the seat backward and forward by loosening and
>> retightening only one bolt, or keep the displacement the same and only
>> change the angle by loosening one bolt as you tighten the other.
>> Brilliant!
>>
>> JG
>
> Back in the day there were a lot of complaints about mounting seats and
> adjusting them with Campy 2 bolt style seatposts (and similar knockoffs).
> It was partly due to not having a proper fitting 10mm wrench to get to the
> bolt heads. The Avocet and similar 2 bolt seatposts that used socket head
> cap screws accessible from the bottom was a great solution.
>
> I've switched most of my bikes back to 2 bolt Campy seatposts.
>

let's say the front bolt breaks for some reason. how would the rear
bolt alone stop the seat bending the clamp and tilting off the bracket?

Tom Kunich

01-04-1970, 11:57 AM

"John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
news:ma7v445rubscfbagoutht0qadrnel4sk56@4ax.com...
>
> I was simply pointing out that a bolt breaking doesn't
> necessarily result in injury -- which you said it did, at first,
> without qualification.

I'm beginning to get the idea that John is starting to use the group to work
off his aggressions which obviously is one of the problems with groups in
general. I suppose it is getting to be time to ignore his postings if they
aren't going to add anything.

jim beam

01-04-1970, 11:58 AM

Tom Kunich wrote:
> "John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
> news:ma7v445rubscfbagoutht0qadrnel4sk56@4ax.com...
>>
>> I was simply pointing out that a bolt breaking doesn't
>> necessarily result in injury -- which you said it did, at first,
>> without qualification.
>
> I'm beginning to get the idea that John is starting to use the group to
> work off his aggressions

that's not an accurate assessment of this situation. this is one of
jobst's favorite games - the switch between aggressor and victim.

rather than admit to [and correct] one of his frequent mistakes, jobst
vociferously and personally attacks instead. then, when the aggressee
defends [naturally, because defense of the mistake is unjustified],
jobst switches and plays the victim of an "unwarranted" attack!

it's grossly inappropriate and highly childish, but apparently a
successful strategy when it comes to soliciting sympathy from those who
are susceptible to suggestion.

> which obviously is one of the problems with
> groups in general. I suppose it is getting to be time to ignore his
> postings if they aren't going to add anything.

Bill Sornson

01-04-1970, 11:58 AM

Tom Kunich wrote:
> "John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
> news:ma7v445rubscfbagoutht0qadrnel4sk56@4ax.com...
>>
>> I was simply pointing out that a bolt breaking doesn't
>> necessarily result in injury -- which you said it did, at first,
>> without qualification.

> I'm beginning to get the idea that John is starting to use the group
> to work off his aggressions which obviously is one of the problems
> with groups in general. I suppose it is getting to be time to ignore
> his postings if they aren't going to add anything.

I plonked ol' Flogittodeathlinson because he's personally abusive and uses
dishonest, weasel tactics (like snipping material to hide or, much worse,
alter meaning).

However, the example you quote above doesn't seem out of line at all. He
simply stated his position (I assume addressed to Brandt, another plonkee.
How dare he challenge the almighty Jobst?).

Bill "off to the ortho (shoulder injury from tire blowout at 40 mph on a
downhill curve two weeks ago, not that anyone asked)" S.

John Forrest Tomlinson

01-04-1970, 11:58 AM

On Wed, 11 Jun 2008 07:07:24 -0700, jim beam
<spamvortex@bad.example.net> wrote:

>Tom Kunich wrote:
>> "John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
>> news:ma7v445rubscfbagoutht0qadrnel4sk56@4ax.com...
>>>
>>> I was simply pointing out that a bolt breaking doesn't
>>> necessarily result in injury -- which you said it did, at first,
>>> without qualification.
>>
>> I'm beginning to get the idea that John is starting to use the group to
>> work off his aggressions
>
>that's not an accurate assessment of this situation. this is one of
>jobst's favorite games - the switch between aggressor and victim.

It's possibly true, but in this case I simply and politiely pointed
out an inconsistency in what Jobst wrote and he then starts
questioning "good faith" rather than simply saying "Yeah, I mispoke"
and leaving it at that.

So I get annoyed.

Tom is still an ass regardless.

01-04-1970, 11:58 AM

Jim, it appears you have done what you constantly accuse Jobst of
doing - talked about something you haven't actually looked at.

The Campy SR post has a semi-circular top with the bolt below on an
inner radius. If it breaks, the clamp wants to slide off. The
Suntour Superb has a cradle top. Should one bolt fail, the clamp is
still cradled on the top of the post.

JG

Tom Kunich

01-04-1970, 11:59 AM

"Bill Sornson" <askme@ask.me> wrote in message
news:484fe580$0$12895$4c368faf@roadrunner.com...
> Tom Kunich wrote:
>> "John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
>> news:ma7v445rubscfbagoutht0qadrnel4sk56@4ax.com...
>>>
>>> I was simply pointing out that a bolt breaking doesn't
>>> necessarily result in injury -- which you said it did, at first,
>>> without qualification.
>
>> I'm beginning to get the idea that John is starting to use the group
>> to work off his aggressions which obviously is one of the problems
>> with groups in general. I suppose it is getting to be time to ignore
>> his postings if they aren't going to add anything.
>
> I plonked ol' Flogittodeathlinson because he's personally abusive and uses
> dishonest, weasel tactics (like snipping material to hide or, much worse,
> alter meaning).

I've been bending over backwards to give him a break because he's been a
REAL(tm) bicycle racer which is rare on these groups. Originally he had a
lot of good things to add and was a nice conservative voice from the pack.
Lately however, he's gotten pretty weird.

jim beam

01-04-1970, 11:59 AM

JG wrote:
> Jim, it appears you have done what you constantly accuse Jobst of
> doing - talked about something you haven't actually looked at.
>
> The Campy SR post has a semi-circular top with the bolt below on an
> inner radius. If it breaks, the clamp wants to slide off. The
> Suntour Superb has a cradle top. Should one bolt fail, the clamp is
> still cradled on the top of the post.
>

i'm aware of that design. and it doesn't have the immediate "dump" fail
mode of which jobst accuses it since the post head and the bottom of the
cradle are in compression. furthermore, the design which jobst holds up
as "superior" really isn't because one bolt at either end of a two-bolt
clamp is incapable of preventing tipping, so you're pretty much in the
same position.

as for ability to follow this thread, you're still making the mistake
jobst wants you to make. jobst's response is that of the righteous
victim. in reality, /he's/ the [unjustified] aggressor - and you need
to learn that distinction. if you can't follow the technical argument,
you're in a difficult position because in most cases, it would be
correct to assume that a "victim" was the one being wronged. but in
this case, the "victim" is actually the one doing the attacking, so
you're [successfully] being suckered.

01-04-1970, 11:59 AM

>i'm aware of that design. and it doesn't have the immediate "dump" fail
>mode of which jobst accuses it since the post head and the bottom of the
>cradle are in compression.

Uh, you mean the compression from the rider sitting on it!?!? That
doesn't make it stable because actually it's under torque... and if
the rider didn't have his weight on the saddle , it wouldn't be a
problem.

Face it, neither you nor Jobst are competent to state the risk rate of
one or two bolt designs. Probably nobody is, as it would require well
controlled actuary data sets with enough incidents to be meaningful.
That leaves only anecdote and thought experiment to persuade.

But why bother? What advantage does a one bolt design have, other
than, "Look Ma! One bolt!", over its obvious drawbacks?

JG

Bill Sornson

01-04-1970, 11:59 AM

Tom Kunich wrote:
> "Bill Sornson" <askme@ask.me> wrote in message
> news:484fe580$0$12895$4c368faf@roadrunner.com...
>> Tom Kunich wrote:
>>> "John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
>>> news:ma7v445rubscfbagoutht0qadrnel4sk56@4ax.com...
>>>>
>>>> I was simply pointing out that a bolt breaking doesn't
>>>> necessarily result in injury -- which you said it did, at first,
>>>> without qualification.
>>
>>> I'm beginning to get the idea that John is starting to use the group
>>> to work off his aggressions which obviously is one of the problems
>>> with groups in general. I suppose it is getting to be time to ignore
>>> his postings if they aren't going to add anything.
>>
>> I plonked ol' Flogittodeathlinson because he's personally abusive
>> and uses dishonest, weasel tactics (like snipping material to hide
>> or, much worse, alter meaning).
>
> I've been bending over backwards to give him a break because he's
> been a REAL(tm) bicycle racer which is rare on these groups.
> Originally he had a lot of good things to add and was a nice
> conservative voice from the pack. Lately however, he's gotten pretty
> weird.

BDS. (Bush Derangement Syndrome.)

Bill "the shoulder's broken" S.

John Forrest Tomlinson

01-04-1970, 12:00 PM

Tom Kunich wrote:
> I've been bending over backwards to give him a break because he's
> been a REAL(tm) bicycle racer which is rare on these groups.
> Originally he had a lot of good things to add and was a nice
> conservative voice from the pack. Lately however, he's gotten pretty
> weird.

No Tom, I just got fed up with your nonsense and stopped being
"polite".

Plus, as the US goes to hell it's even more disturbing to hear nuts
like you and Sorni defending evil. Voting for, say, Bush 1 or Reagan
is something we can disagree on and discuss. Supporting, say, Bush 2
for his second term, after what he's done to the constitution, the
economy and our soldiers is inexcusable and defense of it really shows
who you are. I wish I'd understood you earlier.

Tom Kunich

01-04-1970, 12:00 PM

"John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
news:v530545k1kgic5vt7pqv1i042g4i4vanpd@4ax.com...
>
> No Tom, I just got fed up with your nonsense and stopped being
> "polite".

Because you've gone over the edge don't blame it on someone else.

> Plus, as the US goes to hell it's even more disturbing to hear nuts
> like you and Sorni defending evil.

I find it interesting that you seem intent on spelling Sorinson's name
incorrectly. That has a great deal to say about you.

> Supporting, say, Bush 2
> for his second term, after what he's done to the constitution, the
> economy and our soldiers is inexcusable and defense of it really shows
> who you are. I wish I'd understood you earlier.

What service were you in?

Luke

01-04-1970, 12:00 PM

In article <POudnWnpNOpTjs3VnZ2dnUVZ_rzinZ2d@earthlink.com>, Tom Kunich
<cyclintom@yahoo.> wrote:

> "John Forrest Tomlinson" <usenetremove@jt10000.com> wrote in message
> news:v530545k1kgic5vt7pqv1i042g4i4vanpd@4ax.com...
> >
> > No Tom, I just got fed up with your nonsense and stopped being
> > "polite".
>
> Because you've gone over the edge don't blame it on someone else.
>
> > Plus, as the US goes to hell it's even more disturbing to hear nuts
> > like you and Sorni defending evil.
>
> I find it interesting that you seem intent on spelling Sorinson's name
> incorrectly. That has a great deal to say about you.

Let's give BS his due: his name is spelled S-O-R-N-S-O-N!

jim beam

01-04-1970, 12:01 PM

JG wrote:
>> i'm aware of that design. and it doesn't have the immediate "dump" fail
>> mode of which jobst accuses it since the post head and the bottom of the
>> cradle are in compression.
>
> Uh, you mean the compression from the rider sitting on it!?!? That
> doesn't make it stable because actually it's under torque...

er, that's bending, not torque. and the degree depends on rider
position. any idea how seat rail positioning evolved?

> and if
> the rider didn't have his weight on the saddle , it wouldn't be a
> problem.
>
> Face it, neither you nor Jobst are competent to state the risk rate of
> one or two bolt designs.

really? personally, i feel pretty well qualified to differentiate
between torque and bending.

> Probably nobody is, as it would require well
> controlled actuary data sets with enough incidents to be meaningful.

nobody is qualified to assess risk of one design over another? that's
like saying that the only way you can assess whether a plane is
airworthy is to crash it so you have "enough incidents to be
meaningful"!!!

reality check: every single time you sit on your bike seat and it
doesn't break, that is an "incident" with a positive outcome. the
science of metal fatigue is well advanced and allows very high
confidence for given outcomes like this - provided a designer bothers to
read any of the last century's worth of research on the subject that is.

> That leaves only anecdote and thought experiment to persuade.

what good is "thought experiment" when one doesn't even grasp enough of
the fundamentals to understand the matter at hand?

>
> But why bother? What advantage does a one bolt design have, other
> than, "Look Ma! One bolt!", over its obvious drawbacks?

even clamp loading for one.

as with many things jobstian, grabbing onto one small element of a
design, then broadcasting it as if it's the whole story, leads to gross
misunderstanding. embarrassment for the broadcaster too, if they are
capable of receiving and not just transmitting.

here's reality: double bolt designs offer no significant safety over
single bolt because once one bolt goes, the other is unbalanced and
cannot sustain anything other than a trivial load. properly executed
single bolt designs otoh are absolutely strong enough for the job.
proven non-redundant design elements are used throughout a bicycle.
there's no logical reason, particularly in view of the above, that a
seat post clamp needs, or even can successfully utilize, two bolts.

Tom Kunich

01-04-1970, 12:01 PM

"jim beam" <spamvortex@bad.example.net> wrote in message
news:t_-dnaWJtOGi2c3VnZ2dnUVZ_oDinZ2d@speakeasy.net...
> JG wrote:
>>
>> Uh, you mean the compression from the rider sitting on it!?!? That
>> doesn't make it stable because actually it's under torque...
>
> er, that's bending, not torque. and the degree depends on rider position.
> any idea how seat rail positioning evolved?

As you PEDAL you put rotational loads on the saddle back and forth. You do
understand that don't you?

>> Face it, neither you nor Jobst are competent to state the risk rate of
>> one or two bolt designs.
>
> really? personally, i feel pretty well qualified to differentiate between
> torque and bending.

And you demonstrated that exactly when?

>> Probably nobody is, as it would require well
>> controlled actuary data sets with enough incidents to be meaningful.
>
> nobody is qualified to assess risk of one design over another? that's
> like saying that the only way you can assess whether a plane is airworthy
> is to crash it so you have "enough incidents to be meaningful"!!!

I see.... You don't have a clue about aircraft design either.

jim beam

01-04-1970, 12:01 PM

Tom Kunich wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:t_-dnaWJtOGi2c3VnZ2dnUVZ_oDinZ2d@speakeasy.net...
>> JG wrote:
>>>
>>> Uh, you mean the compression from the rider sitting on it!?!? That
>>> doesn't make it stable because actually it's under torque...
>>
>> er, that's bending, not torque. and the degree depends on rider
>> position. any idea how seat rail positioning evolved?
>
> As you PEDAL you put rotational loads on the saddle back and forth. You
> do understand that don't you?
>
>>> Face it, neither you nor Jobst are competent to state the risk rate of
>>> one or two bolt designs.
>>
>> really? personally, i feel pretty well qualified to differentiate
>> between torque and bending.
>
> And you demonstrated that exactly when?
>
>>> Probably nobody is, as it would require well
>>> controlled actuary data sets with enough incidents to be meaningful.
>>
>> nobody is qualified to assess risk of one design over another? that's
>> like saying that the only way you can assess whether a plane is
>> airworthy is to crash it so you have "enough incidents to be
>> meaningful"!!!
>
> I see.... You don't have a clue about aircraft design either.

tom, this conversation lacks two elements for continuation:

1. a point - because inability to understand the difference between
torque and bending is a fundamental prerequisite.

2. the scent of sincerity - all i smell from you right now is "let's you
and me fight".

one last thing - don't snip content out of context, and /definitely/ not
without annotation. thanks so much.

Tom Kunich

01-04-1970, 12:01 PM

"jim beam" <spamvortex@bad.example.net> wrote in message
news:PL2dnbeeCbFa1M3VnZ2dnUVZ_vzinZ2d@speakeasy.ne t...
> Tom Kunich wrote:
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:t_-dnaWJtOGi2c3VnZ2dnUVZ_oDinZ2d@speakeasy.net...
>>> JG wrote:
>>>>
>>>> Uh, you mean the compression from the rider sitting on it!?!? That
>>>> doesn't make it stable because actually it's under torque...
>>>
>>> er, that's bending, not torque. and the degree depends on rider
>>> position. any idea how seat rail positioning evolved?
>>
>> As you PEDAL you put rotational loads on the saddle back and forth. You
>> do understand that don't you?
>>
>>>> Face it, neither you nor Jobst are competent to state the risk rate of
>>>> one or two bolt designs.
>>>
>>> really? personally, i feel pretty well qualified to differentiate
>>> between torque and bending.
>>
>> And you demonstrated that exactly when?
>>
>>>> Probably nobody is, as it would require well
>>>> controlled actuary data sets with enough incidents to be meaningful.
>>>
>>> nobody is qualified to assess risk of one design over another? that's
>>> like saying that the only way you can assess whether a plane is
>>> airworthy is to crash it so you have "enough incidents to be
>>> meaningful"!!!
>>
>> I see.... You don't have a clue about aircraft design either.
>
> tom, this conversation lacks two elements for continuation:
>
> 1. a point - because inability to understand the difference between torque
> and bending is a fundamental prerequisite.

Perhaps you can explain to me why you're arguing about bending when the rest
of us are discussing the fact that if the bold on a single bolt mechanism
breaks that you have ROTATIONAL forces applied to it?

> 2. the scent of sincerity - all i smell from you right now is "let's you
> and me fight".

You are the one that picks a fight with everything that Jobst writes. Often
you have to really stretch it to force his writing into some sort of form in
order to criticize it.

At times it appears that you actually have a mechanical education but then
you start trying to argue that the important forces on a single bolt
seatpost are BENDING after the bolt has been broken?

> one last thing - don't snip content out of context, and /definitely/ not
> without annotation. thanks so much.

Perhaps you'd be kind enough to take your own advice?

jim beam

01-04-1970, 12:02 PM

Tom Kunich wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:PL2dnbeeCbFa1M3VnZ2dnUVZ_vzinZ2d@speakeasy.ne t...
>> Tom Kunich wrote:
>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>> news:t_-dnaWJtOGi2c3VnZ2dnUVZ_oDinZ2d@speakeasy.net...
>>>> JG wrote:
>>>>>
>>>>> Uh, you mean the compression from the rider sitting on it!?!? That
>>>>> doesn't make it stable because actually it's under torque...
>>>>
>>>> er, that's bending, not torque. and the degree depends on rider
>>>> position. any idea how seat rail positioning evolved?
>>>
>>> As you PEDAL you put rotational loads on the saddle back and forth.
>>> You do understand that don't you?
>>>
>>>>> Face it, neither you nor Jobst are competent to state the risk rate of
>>>>> one or two bolt designs.
>>>>
>>>> really? personally, i feel pretty well qualified to differentiate
>>>> between torque and bending.
>>>
>>> And you demonstrated that exactly when?
>>>
>>>>> Probably nobody is, as it would require well
>>>>> controlled actuary data sets with enough incidents to be meaningful.
>>>>
>>>> nobody is qualified to assess risk of one design over another?
>>>> that's like saying that the only way you can assess whether a plane
>>>> is airworthy is to crash it so you have "enough incidents to be
>>>> meaningful"!!!
>>>
>>> I see.... You don't have a clue about aircraft design either.
>>
>> tom, this conversation lacks two elements for continuation:
>>
>> 1. a point - because inability to understand the difference between
>> torque and bending is a fundamental prerequisite.
>
> Perhaps you can explain to me why you're arguing about bending when the
> rest of us are discussing the fact that if the bold on a single bolt
> mechanism breaks that you have ROTATIONAL forces applied to it?

eh? a bolt is loaded in tension or shear. it's only subject to
rotation when it's being fastened.

>
>> 2. the scent of sincerity - all i smell from you right now is "let's
>> you and me fight".
>
> You are the one that picks a fight with everything that Jobst writes.

that's misrepresentation - i don't bother with the majority of his
emissions - only the stuff that's "tech" and blatantly wrong.

> Often you have to really stretch it to force his writing into some sort
> of form in order to criticize it.
>
> At times it appears that you actually have a mechanical education but
> then you start trying to argue that the important forces on a single
> bolt seatpost are BENDING after the bolt has been broken?

see above.

>
>> one last thing - don't snip content out of context, and /definitely/
>> not without annotation. thanks so much.
>
> Perhaps you'd be kind enough to take your own advice?
>

i haven't snipped a single letter in this thread. you otoh have snipped
whole paragraphs that in fact answered points that you have then tried
to argue against. not very honest of you.

Tom Kunich

01-04-1970, 12:02 PM

"jim beam" <spamvortex@bad.example.net> wrote in message
news:qbydnTEAz6_ayc3VnZ2dnUVZ_sLinZ2d@speakeasy.ne t...
> Tom Kunich wrote:
>>
>> Perhaps you can explain to me why you're arguing about bending when the
>> rest of us are discussing the fact that if the bold on a single bolt
>> mechanism breaks that you have ROTATIONAL forces applied to it?
>
> eh? a bolt is loaded in tension or shear. it's only subject to rotation
> when it's being fastened.

Ahh, I see - you don't understand that we're talking about the SADDLE and
not the bolt. No wonder you don't have any answers that make sense.

>>> 2. the scent of sincerity - all i smell from you right now is "let's you
>>> and me fight".
>>
>> You are the one that picks a fight with everything that Jobst writes.
>
> that's misrepresentation - i don't bother with the majority of his
> emissions - only the stuff that's "tech" and blatantly wrong.

Your idea of "blatant" and the Encyclopedia Britannica are substantially
different.

jim beam

01-04-1970, 12:02 PM

Tom Kunich wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:qbydnTEAz6_ayc3VnZ2dnUVZ_sLinZ2d@speakeasy.ne t...
>> Tom Kunich wrote:
>>>
>>> Perhaps you can explain to me why you're arguing about bending when
>>> the rest of us are discussing the fact that if the bold on a single
>>> bolt mechanism breaks that you have ROTATIONAL forces applied to it?
>>
>> eh? a bolt is loaded in tension or shear. it's only subject to
>> rotation when it's being fastened.
>
> Ahh, I see - you don't understand that we're talking about the SADDLE
> and not the bolt. No wonder you don't have any answers that make sense.

pleeese. the saddle rails bend. what next - discuss the torque effect
of sweat on leather. give us a break.

>
>>>> 2. the scent of sincerity - all i smell from you right now is "let's
>>>> you and me fight".
>>>
>>> You are the one that picks a fight with everything that Jobst writes.
>>
>> that's misrepresentation - i don't bother with the majority of his
>> emissions - only the stuff that's "tech" and blatantly wrong.
>
> Your idea of "blatant" and the Encyclopedia Britannica are substantially
> different.

tom, if you want to play, play it straight. thanks.