Bicycle Drift, revisited...



On Jan 10, 3:11 pm, [email protected] wrote:
> On Thu, 10 Jan 2008 11:55:30 -0800 (PST), "[email protected]"
>
> <[email protected]> wrote:
> >On Jan 10, 2:21 pm, dabac <dabac.32z...@no-
> >mx.forums.cyclingforums.com> wrote:
> >> [email protected] Wrote:

>
> >> > Foot down on a speedway?  

>
> >> Not *on* a speedway. but *during* the specific motorcycle discipline
> >> speedway. Another beast entirely, and very much proper technique.

>
> >> --
> >> dabac

>
> >Ah... gotcha.  Thanks!

>
> Dear Dank,
>
> Example of foot-down speedway technique:
>  http://www.speedwaybikes.com/re/images/99747_19.jpg
>
> Rear view of foot-down in speedway racing:
>  http://www.speedwaybikes.com/video/images/video_p.jpg
>
> View from inside the corner:
>  http://www.speedwaybikes.com/gallery/images/turn1i.jpg
>  http://www.speedwaybikes.com/gallery/images/byebyei.jpg
>
> And here's what you may be thinking of, the rarer knee-down:
>  http://www.speedwaybikes.com/gallery/images/ryan1i.jpg
>
> Lots of speedway racing photos:
>  http://www.speedwaybikes.com/gallery/index.htm
>
> Small videos:
>  http://www.speedwaybikes.com/video/index.htm
>
> This video is slow-motion, which makes it possible to see what's
> happening:
>  http://www.speedwaybikes.com/video/images/bob_lac.avi
>
> Cheers,
>
> Carl Fogel


Dear Carl,

Thanks for the links. Coolness. Once dabac helped me rattle the old
brain I figured out what you were talking about - at first I was
thinking pavement racing. You know, stuff like this:
http://www.motorcyclenews.com/upload/195091/images/snipshot_rossi.jpg

Anyway, we're all on the same page now, forgive the momentary lapse.
 
On Thu, 10 Jan 2008 12:30:59 -0800 (PST), "[email protected]"
<[email protected]> wrote:

>On Jan 10, 3:11 pm, [email protected] wrote:
>> On Thu, 10 Jan 2008 11:55:30 -0800 (PST), "[email protected]"
>>
>> <[email protected]> wrote:
>> >On Jan 10, 2:21 pm, dabac <dabac.32z...@no-
>> >mx.forums.cyclingforums.com> wrote:
>> >> [email protected] Wrote:

>>
>> >> > Foot down on a speedway?  

>>
>> >> Not *on* a speedway. but *during* the specific motorcycle discipline
>> >> speedway. Another beast entirely, and very much proper technique.

>>
>> >> --
>> >> dabac

>>
>> >Ah... gotcha.  Thanks!

>>
>> Dear Dank,
>>
>> Example of foot-down speedway technique:
>>  http://www.speedwaybikes.com/re/images/99747_19.jpg
>>
>> Rear view of foot-down in speedway racing:
>>  http://www.speedwaybikes.com/video/images/video_p.jpg
>>
>> View from inside the corner:
>>  http://www.speedwaybikes.com/gallery/images/turn1i.jpg
>>  http://www.speedwaybikes.com/gallery/images/byebyei.jpg
>>
>> And here's what you may be thinking of, the rarer knee-down:
>>  http://www.speedwaybikes.com/gallery/images/ryan1i.jpg
>>
>> Lots of speedway racing photos:
>>  http://www.speedwaybikes.com/gallery/index.htm
>>
>> Small videos:
>>  http://www.speedwaybikes.com/video/index.htm
>>
>> This video is slow-motion, which makes it possible to see what's
>> happening:
>>  http://www.speedwaybikes.com/video/images/bob_lac.avi
>>
>> Cheers,
>>
>> Carl Fogel

>
>Dear Carl,
>
>Thanks for the links. Coolness. Once dabac helped me rattle the old
>brain I figured out what you were talking about - at first I was
>thinking pavement racing. You know, stuff like this:
>http://www.motorcyclenews.com/upload/195091/images/snipshot_rossi.jpg
>
>Anyway, we're all on the same page now, forgive the momentary lapse.


Dear Dank,

No problem--at first I didn't realize what _you_ meant, so I was
wondering if speedway racers had switched to knee-down slides while my
back was turned. "Speedway" can be a fuzzy term.

Yes, pavement racers use their knees to feel for lean angles.

Trials riders scorn such delicacy. Here's how an expert trials rider
judges a section on the fly:

http://www.youtube.com/watch?v=a09IcYXXR4I

See how Grant Morris determines that traction is better to the left of
his original line? Look at his bike go!

Cheers,

Carl Fogel
 
On Jan 10, 4:04 pm, [email protected] wrote:
> On Thu, 10 Jan 2008 12:30:59 -0800 (PST), "[email protected]"
>
>
>
>
>
> <[email protected]> wrote:
> >On Jan 10, 3:11 pm, [email protected] wrote:
> >> On Thu, 10 Jan 2008 11:55:30 -0800 (PST), "[email protected]"

>
> >> <[email protected]> wrote:
> >> >On Jan 10, 2:21 pm, dabac <dabac.32z...@no-
> >> >mx.forums.cyclingforums.com> wrote:
> >> >> [email protected] Wrote:

>
> >> >> > Foot down on a speedway?

>
> >> >> Not *on* a speedway. but *during* the specific motorcycle discipline
> >> >> speedway. Another beast entirely, and very much proper technique.

>
> >> >> --
> >> >> dabac

>
> >> >Ah... gotcha. Thanks!

>
> >> Dear Dank,

>
> >> Example of foot-down speedway technique:
> >> http://www.speedwaybikes.com/re/images/99747_19.jpg

>
> >> Rear view of foot-down in speedway racing:
> >> http://www.speedwaybikes.com/video/images/video_p.jpg

>
> >> View from inside the corner:
> >> http://www.speedwaybikes.com/gallery/images/turn1i.jpg
> >> http://www.speedwaybikes.com/gallery/images/byebyei.jpg

>
> >> And here's what you may be thinking of, the rarer knee-down:
> >> http://www.speedwaybikes.com/gallery/images/ryan1i.jpg

>
> >> Lots of speedway racing photos:
> >> http://www.speedwaybikes.com/gallery/index.htm

>
> >> Small videos:
> >> http://www.speedwaybikes.com/video/index.htm

>
> >> This video is slow-motion, which makes it possible to see what's
> >> happening:
> >> http://www.speedwaybikes.com/video/images/bob_lac.avi

>
> >> Cheers,

>
> >> Carl Fogel

>
> >Dear Carl,

>
> >Thanks for the links. Coolness. Once dabac helped me rattle the old
> >brain I figured out what you were talking about - at first I was
> >thinking pavement racing. You know, stuff like this:
> >http://www.motorcyclenews.com/upload/195091/images/snipshot_rossi.jpg

>
> >Anyway, we're all on the same page now, forgive the momentary lapse.

>
> Dear Dank,
>
> No problem--at first I didn't realize what _you_ meant, so I was
> wondering if speedway racers had switched to knee-down slides while my
> back was turned. "Speedway" can be a fuzzy term.
>
> Yes, pavement racers use their knees to feel for lean angles.
>
> Trials riders scorn such delicacy. Here's how an expert trials rider
> judges a section on the fly:
>
> http://www.youtube.com/watch?v=a09IcYXXR4I
>
> See how Grant Morris determines that traction is better to the left of
> his original line? Look at his bike go!
>
> Cheers,
>
> Carl Fogel- Hide quoted text -
>
> - Show quoted text -


hahahaa.... great clip! I almost bought a trials bike a while back,
to replace my CR125. Some of the obstacles that I had to conquer to
get to the trails/pits seemed like they'd be a blast on a trials,
where they were a PITA on a tuned 2-stroke pro-circuit MX bike. I
decided that while it may make getting to the pits easier, the amount
of fun my CR was once I got it to the pits outweighed any benefits of
the trials bike. Very cool stuff though, and sweet video.
 
Dan K? writes:

>>> I doubt it's what's happening here, but steel-soled (yes, sole)
>>> shoes are used in flat-track (dirt) motorcycle racing for the
>>> inside foot. This is probably a bit for wear, a bit for friction.


http://www.bumblebee77.com/Ken Maeley Hot Shoe.JPG

>>> The technique is not so much controversial as debatable: in theory
>>> you can reduce a little bit of the cornering load on the tires by
>>> adding your foot as a third support point or to catch a momentary
>>> bobble, but some of the fastest riders go through corners with
>>> both feet on the pegs.


http://www.amaflattrack.com/

>> They're just recovering trials riders. :)


>> Off-road, riders often put the inside foot down--see any motocross.


>> The best place for foot-down power-sliding is the speedway, where
>> the machines are designed for that, right down to the
>> short-on-the-right handlebar that wiki fails to mention:


http://en.wikipedia.org/wiki/Motorcycle_speedway

> Foot down on a speedway? Having read a book or two on motorcycle
> racing, I don't recall hearing of putting a foot down. Isn't it
> more common to put the knee down, allowing the bike to achieve a
> greater lean, hence the market for things like knee pucks?
> It's my understanding that the knee is sometimes used to help support
> the bike, but other times is only used to help gauge the angle of the
> lean and just how close the bike is to leaning too far and planting
> some other part of the bike down, lifting the rear wheel off of the
> ground and causing a crash.


I don't thing reading books on motorcycle road racing covers flat dirt
track riding styles. Traction on a dirt track is not good enough to
lean a bike to knee dragging angles. You'll notice the track is
watered in most of these scenes. Some tracks are practically slick
hard wet clay. They use a steel slip-on shell on the boot.

Here are some pix:

http://www.vft.org/2007/2007_11Nov18SCFTAPerris.html

Jobst Brandt
 
On Jan 10, 4:45 pm, [email protected] wrote:
> Dan K? writes:
> >>> I doubt it's what's happening here, but steel-soled (yes, sole)
> >>> shoes are used in flat-track (dirt) motorcycle racing for the
> >>> inside foot.  This is probably a bit for wear, a bit for friction.

>
>  http://www.bumblebee77.com/Ken Maeley Hot Shoe.JPG
>
> >>> The technique is not so much controversial as debatable: in theory
> >>> you can reduce a little bit of the cornering load on the tires by
> >>> adding your foot as a third support point or to catch a momentary
> >>> bobble, but some of the fastest riders go through corners with
> >>> both feet on the pegs.

>
>  http://www.amaflattrack.com/
>
> >> They're just recovering trials riders. :)
> >> Off-road, riders often put the inside foot down--see any motocross.
> >> The best place for foot-down power-sliding is the speedway, where
> >> the machines are designed for that, right down to the
> >> short-on-the-right handlebar that wiki fails to mention:

>
>  http://en.wikipedia.org/wiki/Motorcycle_speedway
>
> > Foot down on a speedway?  Having read a book or two on motorcycle
> > racing, I don't recall hearing of putting a foot down.  Isn't it
> > more common to put the knee down, allowing the bike to achieve a
> > greater lean, hence the market for things like knee pucks?
> > It's my understanding that the knee is sometimes used to help support
> > the bike, but other times is only used to help gauge the angle of the
> > lean and just how close the bike is to leaning too far and planting
> > some other part of the bike down, lifting the rear wheel off of the
> > ground and causing a crash.

>
> I don't thing reading books on motorcycle road racing covers flat dirt
> track riding styles.  Traction on a dirt track is not good enough to
> lean a bike to knee dragging angles.  You'll notice the track is
> watered in most of these scenes.  Some tracks are practically slick
> hard wet clay.  They use a steel slip-on shell on the boot.  
>
> Here are some pix:
>
> http://www.vft.org/2007/2007_11Nov18SCFTAPerris.html
>
> Jobst Brandt


Jobst,

We're past that, and have it figured out. We were thinking of
different types of speedways. Thanks all the same.
 
On 10 Jan 2008 21:45:14 GMT, [email protected] wrote:


>I don't think reading books on motorcycle road racing covers flat dirt
>track riding styles. Traction on a dirt track is not good enough to
>lean a bike to knee dragging angles. You'll notice the track is
>watered in most of these scenes. Some tracks are practically slick
>hard wet clay. They use a steel slip-on shell on the boot.
>
>Here are some pix:
>
>http://www.vft.org/2007/2007_11Nov18SCFTAPerris.html
>
>Jobst Brandt


Dear Jobst,

Actually, the speedway racers in that linke are heeled over so far in
the turns that their knees would be touching the ground, but they
almost invariably have the inside foot well out from under:
http://www.speedwaybikes.com/gallery/calfast.htm

Somtimes a rider trails a knee in the dirt, but it's not good
technique:
http://www.speedwaybikes.com/gallery/images/ryan1i.jpg

Cheers,

Carl Fogel
 
Carl Fogel writes:

>> I don't think reading books on motorcycle road racing covers flat
>> dirt track riding styles. Traction on a dirt track is not good
>> enough to lean a bike to knee dragging angles. You'll notice the
>> track is watered in most of these scenes. Some tracks are
>> practically slick hard wet clay. They use a steel slip-on shell on
>> the boot.


>> Here are some pix:


http://www.vft.org/2007/2007_11Nov18SCFTAPerris.html

> Actually, the speedway racers in that Link are heeled over so far in
> the turns that their knees would be touching the ground, but they
> almost invariably have the inside foot well out from under:


http://www.speedwaybikes.com/gallery/calfast.htm

> Sometimes a rider trails a knee in the dirt, but it's not good
> technique:


http://www.speedwaybikes.com/gallery/images/ryan1i.jpg

I think there is a misunderstanding of cornering forces between
pavement and dirt. Dirt does not have the traction that leaning road
riders use entirely by tire contact. In the pictures of flat track
racing with low lean angles, riders could not pick up their foot from
the track an stay upright for even a moment. There is significant
weight on the sliding foot on dirt, while the road rider puts no
weight on the knee or elbow that gets close to the road. The plastic
buttons on their leathers are there for intermittent and incidental
road contact, not for supporting weight.

Meanwhile, do not forget that road (pavement) race cars corner a more
than 3g's which would be a lean angle for a motorcycle of about 18.5°
making evident that unless the M/C cab cut corners, the car is always
faster in turns. You cannot lean an M/C anywhere near that close to
the ground for several reasons. That includes first that the M/C tire
does not have enough traction, being round in cross section, that
leaned at such an angle the tire would be essentially a street sweeper
broom with lots of scrub between inner and outer edge of road contact.
And finally, all sorts of hardware (engine and transmission would
scrape on the road.

Most folks have never seen a GT or F1 race on a course like the
Nürburgring that has many mountain curves. These cars corner like
slot-cars and one naturally wonders what holds them to the road. This
quickly brings to mind that motorcycles are not faster than cars of
the same class (in curves as is commonly believed).

Of course bicycles are far behind M/C's in that respect, both because
the traction isn't there and because few riders are young enough to
have tested the limits.

Here are some of those fast guys and a gal.

http://geocities.com/rayhosler/coastrangeslides/coastrange.html

Jobst Brandt
 
[email protected] aka Jobst Brandt wrote:

> ...
> Meanwhile, do not forget that road (pavement) race cars corner a more
> than 3g's which would be a lean angle for a motorcycle of about 18.5°
> making evident that unless the M/C cab cut corners, the car is always
> faster in turns. You cannot lean an M/C anywhere near that close to
> the ground for several reasons. That includes first that the M/C tire
> does not have enough traction, being round in cross section, that
> leaned at such an angle the tire would be essentially a street sweeper
> broom with lots of scrub between inner and outer edge of road contact.
> And finally, all sorts of hardware (engine and transmission would
> scrape on the road.


Yes, but only cars with significant aerodynamic down force corner
anywhere near 3g. Without down force, the traction limit is around 1.2
to 1.3g on warmed up racing slicks.

> Most folks have never seen a GT or F1 race on a course like the
> Nürburgring that has many mountain curves.


Old or new Nürburgring?

> These cars corner like
> slot-cars and one naturally wonders what holds them to the road. This
> quickly brings to mind that motorcycles are not faster than cars of
> the same class (in curves as is commonly believed).


What is there to wonder about? The aerodynamic devices are hardly hidden.

> Of course bicycles are far behind M/C's in that respect, both because
> the traction isn't there and because few riders are young enough to
> have tested the limits....


I just need to find some good hip and elbow pads, and some sacrificial
foam to protect the seat. Falling does not hurt much when you are only
20 cm from the ground when traction loss occurs.

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

>> Meanwhile, do not forget that road (pavement) race cars corner a
>> more than 3g's which would be a lean angle for a motorcycle of
>> about 18.5° making evident that unless the M/C cab cut corners, the
>> car is always faster in turns. You cannot lean an M/C anywhere
>> near that close to the ground for several reasons. That includes
>> first that the M/C tire does not have enough traction, being round
>> in cross section, that leaned at such an angle the tire would be
>> essentially a street sweeper broom with lots of scrub between inner
>> and outer edge of road contact. And finally, all sorts of hardware
>> (engine and transmission would scrape on the road.


> Yes, but only cars with significant aerodynamic down force corner
> anywhere near 3g. Without down force, the traction limit is around
> 1.2 to 1.3g on warmed up racing slicks.


Yes butt! You better check your sources. Nearly slick tires achieve
these cornering forces in low speed curves as well. Drag Racers
achieve more than 4g's even at the start and average 5g's+ for the
quarter mile.

>> Most folks have never seen a GT or F1 race on a course like the
>> Nürburgring that has many mountain curves.


> Old or new Nürburgring?


The north course, of course 26km.

http://de.wikipedia.org/wiki/Nordschleife

>> These cars corner like slot-cars and one naturally wonders what
>> holds them to the road. This quickly brings to mind that
>> motorcycles are not faster than cars of the same class (in curves
>> as is commonly believed).


> What is there to wonder about? The aerodynamic devices are hardly
> hidden.


You haven't seen it and don't know what you are talking about. Just
as standing behind the start of a top fuel drag race one does not get
the impression of speed but rather that of watching a zoom lens being
exercised. The car gets smaller so fast it violates ones
understanding of acceleration, much like the announcer who said "Watch
that airplane" as the X1 fires its rockets and vanished instantly,
even though it is flying in the line of sight.

>> Of course bicycles are far behind M/C's in that respect, both
>> because the traction isn't there and because few riders are young
>> enough to have tested the limits...


> I just need to find some good hip and elbow pads, and some
> sacrificial foam to protect the seat. Falling does not hurt much
> when you are only 20 cm from the ground when traction loss occurs.


I think you need to compare your model with the guy on roller-blade
wheels in the Alps.

Jobst Brandt
 
On Jan 6, 7:04 pm, "Paul M. Hobson" <[email protected]> wrote:
> A while back, there was a thread discussing the technique, equipment,
> and road conditions required to "peel out" on a bicycle like this:http://www.youtube.com/watch?v=PzC6yU6DhkY
>
> I won't pretend to know exactly where this footage was shot. But I
> wonder if the video below could possibly shed some insight into the road
> surface that allows such a feat to be possible:http://www.youtube.com/watch?v=hwdZl2BpDAc
>
> Any thoughts?


I finally got a response from my friend who's in Baghdad. (As you
might expect, he doesn't have much time for e-mail.) Here's what he
said:

"I've seen the bicycle video before and I saw a similar car video
(except in the one I saw the idiots crashed into the crowd) -- I think
the heat and type of road surface has a lot to do with it... the road
surfaces are very, very smooth in Baghdad, maybe from the tar
constantly melting in the heat. Since it often goes the better part
of a year without rain, the oil build up often makes it like an ice
rink at 120 degrees... I've seen people slip and fall walking along
some roads. I think a combination of that and the super-fine sand
everywhere allowed the guy on the bike to spin his rear wheel like
that... and, obviously, that he didn't have much weight on the back
tire.

I think it's fair to say that it's not icy. You should see the layers
the locals put on when it goes down to just 50 or so."

Regarding the "super-fine sand," this is the guy who told me that the
sand can be like talcum powder. Each step you take can raise a little
cloud of sand dust.

- Frank Krygowski
 
Paul M. Hobson wrote:
> A while back, there was a thread discussing the technique, equipment,
> and road conditions required to "peel out" on a bicycle like this:
> http://www.youtube.com/watch?v=PzC6yU6DhkY
>
> I won't pretend to know exactly where this footage was shot. But I
> wonder if the video below could possibly shed some insight into the road
> surface that allows such a feat to be possible:
> http://www.youtube.com/watch?v=hwdZl2BpDAc
>
> Any thoughts?
> \\paul



I supposed one could consider this oddly on topic for this thread:
http://news.bbc.co.uk/2/hi/middle_east/7193784.stm

\\paul
 
Thanks for the follow up, Frank. In my mind, that settles it.

\\paul
 
On Thu, 17 Jan 2008 11:03:27 -0500, "Paul M. Hobson"
<[email protected]> wrote:

>Paul M. Hobson wrote:
>> A while back, there was a thread discussing the technique, equipment,
>> and road conditions required to "peel out" on a bicycle like this:
>> http://www.youtube.com/watch?v=PzC6yU6DhkY
>>
>> I won't pretend to know exactly where this footage was shot. But I
>> wonder if the video below could possibly shed some insight into the road
>> surface that allows such a feat to be possible:
>> http://www.youtube.com/watch?v=hwdZl2BpDAc
>>
>> Any thoughts?
>> \\paul

>
>
>I supposed one could consider this oddly on topic for this thread:
>http://news.bbc.co.uk/2/hi/middle_east/7193784.stm
>
>\\paul


Dear Paul,

Here's a nice weather page for Riyadh, which shows daily how far it is
to the nearest place where frost is predicted:

http://www.weather-forecast.com/locations/Riyadh/forecasts/latest/weather_finder

The nearest frost is usually 500 miles north (or further) in Iran in
winter. The Riyadh weather forecaster is pretty desperate for
material.

***

Here are the monthly minimum and maxium and maximum temperatures for
Riyadh:

http://www.weatherunderground.com/NORMS/DisplayIntlNORMS.asp?CityCode=40438&Units=both

Usually Riyadh varies from 47F to 66F in January. The BBC shows not
only averages, but record temperatures. Riyadh has gotten as cold as
-7C in some long ago January:

http://www.bbc.co.uk/weather/world/city_guides/results.shtml?tt=TT002770

***

So far this month, the Riyadh temperature has ranged from 70F down to
an incredible 28F this morning, the coldest that it's been this
century and clear evidence of the cold snap that you mention:

http://www.weatherunderground.com/h...tml?req_city=NA&req_state=NA&req_statename=NA

I blame global warming. :)

Cheers,

Carl Fogel