Another scary crash video

Scott

On Jun 22, 3:41*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
wrote:
> On Sat, 21 Jun 2008 19:04:05 -0700 (PDT), Scott
>
> <hendricks_sc...@hotmail.com> wrote:
> >It's not widely known (at least as far as I can tell from talking to
> >folks about steering geometry) but bikes have a built-in tendency to
> >upright themselves and go straight if you apply too much front brake
>
> You're joking about this being "not widely known", right?

If by joking about it not being widely known, you mean I should've
said 'not known at all', then yeah... I was joking.

If you're implying that it's more widely understood than I think, then
you must be joking. I've never spoken to another racer who understood
that a bicycle has a natural tendency to upright itself and go
straight when applying front brake forces. Lot's of folks may do it
intuitively, but aside from the folks who've written the articles
which I've read on the matter, I haven't found anyone who was aware or
or understood the physics behind the phenomenon.

Hell, I don't understand the physics, but I know that before I apply
my front brake while turning I have to put a bit more force into the
inside handlebar to counter the effect. My situation is complicated
even further because I like my bikes to have a bit more trail than
most, and therefore my bikes will straighten up more quickly than
most.

John Forrest Tomlinson

On Sun, 22 Jun 2008 07:12:20 -0700 (PDT), Scott
<hendricks_scott@hotmail.com> wrote:

>I've never spoken to another racer who understood
>that a bicycle has a natural tendency to upright itself and go
>straight when applying front brake forces. Lot's of folks may do it
>intuitively, but aside from the folks who've written the articles
>which I've read on the matter, I haven't found anyone who was aware or
>or understood the physics behind the phenomenon.

So what? Good riders know if they hit the braks the bike goes up, so
they try not to do it mid-turn. They dont' udnerstand the physics -
so what?

Well, I guess you're smarter and better read than most. Congrats.

Scott

On Jun 22, 9:11*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
wrote:
> On Sun, 22 Jun 2008 07:12:20 -0700 (PDT), Scott
>
> <hendricks_sc...@hotmail.com> wrote:
> >I've never spoken to another racer who understood
> >that a bicycle has a natural tendency to upright itself and go
> >straight when applying front brake forces. *Lot's of folks may do it
> >intuitively, but aside from the folks who've written the articles
> >which I've read on the matter, I haven't found anyone who was aware or
> >or understood the physics behind the phenomenon.
>
> So what? *Good riders know if they hit the braks the bike goes up, so
> they try not to do it mid-turn. *They dont' udnerstand the physics -
> so what?
>
> Well, I guess you're smarter and better read than most. *Congrats.

Help me out here, why are you so argumentative this morning?

FWIW, if you were to take a poll on your next group ride, I think
you'd be very surprised how few riders, or racers for that matter,
know anything at all about how trail is determined, the inverse
relationship to offset and trail, or how trail effects steering or
what happens under braking forces. I'm not suggesting that good
riders don't do certain things intuitively, I merely pointed out from
my viewing of the video that it appeared that Schleck over-braked,
then panicked.

If you want to argue about this, send an email to TK or something.
I'm not in the mood, I'm on the way out the door for a nice ride in
the mountains.

Donald Munro

Scott wrote:
> Help me out here, why are you so argumentative this morning?

He's a Dutch football supporter ?

Ted van de Weteringe

Donald Munro schreef:
> Scott wrote:
>> Help me out here, why are you so argumentative this morning?
>
> He's a Dutch football supporter ?

These are tough times for them. On the other hand, I am just glad the
late night neighbourhood noise will slowly subside.

-old fart

John Forrest Tomlinson

On Sun, 22 Jun 2008 08:24:42 -0700 (PDT), Scott
<hendricks_scott@hotmail.com> wrote:

>On Jun 22, 9:11*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
>wrote:
>> On Sun, 22 Jun 2008 07:12:20 -0700 (PDT), Scott
>>
>> <hendricks_sc...@hotmail.com> wrote:
>> >I've never spoken to another racer who understood
>> >that a bicycle has a natural tendency to upright itself and go
>> >straight when applying front brake forces. *Lot's of folks may do it
>> >intuitively, but aside from the folks who've written the articles
>> >which I've read on the matter, I haven't found anyone who was aware or
>> >or understood the physics behind the phenomenon.
>>
>> So what? *Good riders know if they hit the braks the bike goes up, so
>> they try not to do it mid-turn. *They dont' udnerstand the physics -
>> so what?
>>
>> Well, I guess you're smarter and better read than most. *Congrats.
>
>Help me out here, why are you so argumentative this morning?

People bragging about how they know stuff that others don't annoys me.

>
>FWIW, if you were to take a poll on your next group ride, I think
>you'd be very surprised how few riders, or racers for that matter,
>know anything at all about how trail is determined,

Who cares? I don't. I know if I hit the brakes when leaned over hard
in a corner I'll either slide out or the bike will jerk upright.
That's enough. Good racers know that.

But I'm not as knowledgeable as you, so...

Scott

On Jun 22, 11:31*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
wrote:
> On Sun, 22 Jun 2008 08:24:42 -0700 (PDT), Scott
>
>
>
>
>
> <hendricks_sc...@hotmail.com> wrote:
> >On Jun 22, 9:11*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
> >wrote:
> >> On Sun, 22 Jun 2008 07:12:20 -0700 (PDT), Scott
>
> >> <hendricks_sc...@hotmail.com> wrote:
> >> >I've never spoken to another racer who understood
> >> >that a bicycle has a natural tendency to upright itself and go
> >> >straight when applying front brake forces. *Lot's of folks may do it
> >> >intuitively, but aside from the folks who've written the articles
> >> >which I've read on the matter, I haven't found anyone who was aware or
> >> >or understood the physics behind the phenomenon.
>
> >> So what? *Good riders know if they hit the braks the bike goes up, so
> >> they try not to do it mid-turn. *They dont' udnerstand the physics -
> >> so what?
>
> >> Well, I guess you're smarter and better read than most. *Congrats.
>
> >Help me out here, why are you so argumentative this morning?
>
> People bragging about how they know stuff that others don't annoys me.
>
>
>
> >FWIW, if you were to take a poll on your next group ride, I think
> >you'd be very surprised how few riders, or racers for that matter,
> >know anything at all about how trail is determined,
>
> Who cares? I don't. I know if I hit the brakes when leaned over hard
> in a corner I'll either slide out or the bike will jerk upright.
> That's enough. *Good racers know that.
>
> But I'm not as knowledgeable as you, so...- Hide quoted text -
>
> - Show quoted text -

1st, I wasn't bragging. 2nd, I can't help it if I know more than
you. :->

JT, let's not quibble over this. Ain't worth it.

John Forrest Tomlinson

On Sun, 22 Jun 2008 12:50:01 -0700 (PDT), Scott
<hendricks_scott@hotmail.com> wrote:


>1st, I wasn't bragging. 2nd, I can't help it if I know more than
>you. :->


No quibbles -- just re-think this sort of statement "I've never spoken
to another racer who understood that a bicycle has a natural tendency
to upright itself and go straight when applying front brake forces."

Scott

On Jun 22, 4:15*pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
wrote:
> On Sun, 22 Jun 2008 12:50:01 -0700 (PDT), Scott
>
> <hendricks_sc...@hotmail.com> wrote:
> >1st, I wasn't bragging. *2nd, I can't help it if I know more than
> >you. *:->
>
> No quibbles -- just re-think this sort of statement "I've never spoken
> to another racer who understood that a bicycle has a natural tendency
> to upright itself and go straight when applying front brake forces."

What's to rethink? I haven't. I don't talk to that many people,
though. :-)

Most know they shouldn't brake in a corner, but few (in my experience)
know why.

Anyway, I didn't mean to set you off this morning. I was caught off-
guard 'cause you're rarely reactionary or overly sensitive. Peace.

Paul G.

On Jun 22, 3:15*pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
wrote:
> On Sun, 22 Jun 2008 12:50:01 -0700 (PDT), Scott
>
> <hendricks_sc...@hotmail.com> wrote:
> >1st, I wasn't bragging. *2nd, I can't help it if I know more than
> >you. *:->
>
> No quibbles -- just re-think this sort of statement "I've never spoken
> to another racer who understood that a bicycle has a natural tendency
> to upright itself and go straight when applying front brake forces."

Yes, that's a bold statement but where are the equations to support
it? Every competent racer of Category 1 and most of the Cat 2's can
do the math in their heads, real time. The leaning equation is:
http://tinyurl.com/5rpp6k

and the steering equation is:
http://tinyurl.com/3wr9mf

where

* èr is the lean angle of the rear assembly,
* ø is the steer angle of the front assembly relative to the rear
assembly and
* Mè and Mø are the moments (torques) applied at the rear assembly
and the steering axis, respectively.

Most of the rider-error crashes in turns you see in pro races are due
to poor math skills.
-Paul

bjw@mambo.ucolick.org

On Jun 19, 10:05*pm, Michael Press <rub...@pacbell.net> wrote:
> In article
> <d0f865db-c487-4390-9743-250519259...@d19g2000prm.googlegroups.com>,
>
>
>
> *"b...@mambo.ucolick.org" <b...@mambo.ucolick.org> wrote:
> > On Jun 19, 7:26*am, raam...@gmail.com wrote:
> > > On Jun 19, 8:23*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
> > > wrote:
>
> > > > Yeah. Perhaps rider error, perhaps oil. If I heard later his tire
> > > > flatted just then I wouldn't be surprised either. *But NOT severe
> > > > frame flex for those bikes specifically.
>
> > > not severe flex, but just enough under load- or something else about
> > > the frame- last year at the tdf there were a couple of occaisions
> > > where the csc rider was unable to negoiate the curve on a descent,
> > > whereas other riders did- *anyone re-watching the tdf2007 dvds might
> > > just take a note of the number of times a csc rider had trouble on a
> > > curve
>
> > Side load on a head tube, or just about any frame
> > part, during a descent is essentially zero. *Bicycles
> > lean into corners rather than scrubbing tires like cars.
> > I could see issues from either an ultra flexy fork or
> > flex in a really long steerer and headtube (which can
> > contribute to shimmy), but hardly any of these guys
> > ride such a frame.
>
> I do not think it is that simple.
> What you describe is true for a constant curvature turn.
> Descents require very hard changes in the
> bicycle's aspect. This puts forces every
> which way on the front of the bicycle.
>

I don't think it's that complicated. Although the bike lean
angle changes as you enter and exit turns, it does so
gradually. Turns are initiated by small amounts of
countersteer and your COG is more or less in plane
with the wheel. While descending, you never turn the
handlebars very far, even if you really have to slow
down to enter a turn. The majority of the force on the
headtube is not side load, but fore-aft from braking
force. There are exceptions, like if you are doing a
slow-speed technical MTB descent, but they're not
relevant to Schleck's Cervelo.

You can put a side load on the head tube while climbing
or sprinting when you lean the bike and pull on the
handlebars. When descending, you would rarely
put that kind of force on the handlebar. I think if you're
descending on the road and you manage to put a large
side load on the head tube, you're going to fall down,
and it has nothing to do with magical frame-flex
properties.

Ben

Michael Press

In article <h03t5456tdkhon97aame6aigvigh2dn46m@4ax.com>,
John Forrest Tomlinson <usenetremove@jt10000.com> wrote:

> On Sun, 22 Jun 2008 08:24:42 -0700 (PDT), Scott
> <hendricks_scott@hotmail.com> wrote:
>
> >On Jun 22, 9:11*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
> >wrote:
> >> On Sun, 22 Jun 2008 07:12:20 -0700 (PDT), Scott
> >>
> >> <hendricks_sc...@hotmail.com> wrote:
> >> >I've never spoken to another racer who understood
> >> >that a bicycle has a natural tendency to upright itself and go
> >> >straight when applying front brake forces. *Lot's of folks may do it
> >> >intuitively, but aside from the folks who've written the articles
> >> >which I've read on the matter, I haven't found anyone who was aware or
> >> >or understood the physics behind the phenomenon.
> >>
> >> So what? *Good riders know if they hit the braks the bike goes up, so
> >> they try not to do it mid-turn. *They dont' udnerstand the physics -
> >> so what?
> >>
> >> Well, I guess you're smarter and better read than most. *Congrats.
> >
> >Help me out here, why are you so argumentative this morning?
>
> People bragging about how they know stuff that others don't annoys me.
>
> >
> >FWIW, if you were to take a poll on your next group ride, I think
> >you'd be very surprised how few riders, or racers for that matter,
> >know anything at all about how trail is determined,
>
> Who cares? I don't. I know if I hit the brakes when leaned over hard
> in a corner I'll either slide out or the bike will jerk upright.
> That's enough. Good racers know that.

Does Schleck know that? Or did Schleck spill for some
reason other than what Scott says?

--
Michael Press

John Forrest Tomlinson

On Sun, 22 Jun 2008 23:55:44 -0700, Michael Press <rubrum@pacbell.net>
wrote:

>In article <h03t5456tdkhon97aame6aigvigh2dn46m@4ax.com>,
> John Forrest Tomlinson <usenetremove@jt10000.com> wrote:
>
>> On Sun, 22 Jun 2008 08:24:42 -0700 (PDT), Scott
>> <hendricks_scott@hotmail.com> wrote:
>>
>> >On Jun 22, 9:11*am, John Forrest Tomlinson <usenetrem...@jt10000.com>
>> >wrote:
>> >> On Sun, 22 Jun 2008 07:12:20 -0700 (PDT), Scott
>> >>
>> >> <hendricks_sc...@hotmail.com> wrote:
>> >> >I've never spoken to another racer who understood
>> >> >that a bicycle has a natural tendency to upright itself and go
>> >> >straight when applying front brake forces. *Lot's of folks may do it
>> >> >intuitively, but aside from the folks who've written the articles
>> >> >which I've read on the matter, I haven't found anyone who was aware or
>> >> >or understood the physics behind the phenomenon.
>> >>
>> >> So what? *Good riders know if they hit the braks the bike goes up, so
>> >> they try not to do it mid-turn. *They dont' udnerstand the physics -
>> >> so what?
>> >>
>> >> Well, I guess you're smarter and better read than most. *Congrats.
>> >
>> >Help me out here, why are you so argumentative this morning?
>>
>> People bragging about how they know stuff that others don't annoys me.
>>
>> >
>> >FWIW, if you were to take a poll on your next group ride, I think
>> >you'd be very surprised how few riders, or racers for that matter,
>> >know anything at all about how trail is determined,
>>
>> Who cares? I don't. I know if I hit the brakes when leaned over hard
>> in a corner I'll either slide out or the bike will jerk upright.
>> That's enough. Good racers know that.
>
>Does Schleck know that? Or did Schleck spill for some
>reason other than what Scott says?

You're playing both sides. On the one hand you say you're not
bragging, you're only saying you're one of the few people who
understand on a conceptual or theoretical level the problem.

And on the other hand there's youre comment above, which suggests mor
than that.

And yes, Schleck knows that. Doesn't mean he can't make a mistake.

Donald Munro

Paul G. wrote:
> Yes, that's a bold statement but where are the equations to support it?
> Every competent racer of Category 1 and most of the Cat 2's can do the
> math in their heads, real time. The leaning equation is:
> http://tinyurl.com/5rpp6k
>
> and the steering equation is:
> http://tinyurl.com/3wr9mf
>
> where
>
> * θr is the lean angle of the rear assembly, * ψ is the steer angle
> of the front assembly relative to the rear
> assembly and
> * Mθ and Mψ are the moments (torques) applied at the rear assembly
> and the steering axis, respectively.
>
> Most of the rider-error crashes in turns you see in pro races are due to
> poor math skills.

Dumbass,
Why do you have a bike computer if you can't use it to do the math for
you ? My computer can even generate a naked view simulation of the hot
chick in front of me's ass.