track tubulars

In article ,
wrote:

On Fri, 25 Feb 2005 21:51:17 -0800, Ryan Cousineau
wrote:

In article ,
wrote:

Dear Ron,

The motorcycle side of the thread ended up distinguishing
"tread creep" from true sliding.

Actually breaking the tires loose from the pavement while
cornering has about the same effect on any two-wheeled
vehicle, no matter how it's powered.

Maybe this just ups the noise ratio, but the received wisdom in
motorcycle road racing is that the fastest riders really are able to
consistently slide both tires in a turn. I'm pretty sure this is
dependent on very special tires, applying major power, and abnormally
good bike-control skills.

Probably easier to just work on your climbing skills,

Dear Ryan,

Here's a link to where Mark McMaster seemed to nail the
slithery details down:

http://tinyurl.com/5ppsw

The question seemed to be whether it was a true slide (all
the rubber breaking loose) or a squirm-walk-creep-roll.

It doesn't seem to depend on terribly special tires, just
wide enough for the squirm to occur (road bicycle tires
haven't the width or the thickness of tread to do this).

Carl Fogel

I am...skeptical that squirm accounts for all of the sliding sensation
that elite motorcycle racers experience. Just so we are clear on the
vehicles in question and the nature of the tires:

http://www.cqq.ch/Moto/1Moto_images/.../GP-Vale_2.jpg
http://www.dreamgate.ne.jp/nsr/Gallery/03_gp_10.jpg

These are photos of some Italian named Rossi. I'm not sure he's any
good, since his number is 46, and not 1, and he's riding a Honda, and I
heard a Yamaha won MotoGP last year.

Those are pure slick tires, of course. Zero tread. I don't have the
engineering chops to discuss slip angles in any depth, and I readily
concede that this is moot when compared to cycling experiences, as
nobody has as much horsepower as even the most asthmatic YSR50:

http://phhauchard.free.fr/double/ysr50.jpg

But it seems to me that any squirm on these front tires would have to be
trying to roll the tire almost completely perpendicular to the long axis
of the tire. Unfortunately, I couldn't find a smoking gun in any of
these photos, which might be faint slide marks the right size and
location to be left by the front tire.

I also have this other photo, which seems to assert that it is possible
to corner at speed with the front tire neither slipping nor squirming.
Indeed, the rider hardly seems to need it at all:

http://www.riverside-jp.com/new/rs250b.jpg

--
Ryan Cousineau, http://www.wiredcola.com
Verus de parvis; verus de magnis.

On Sat, 26 Feb 2005 09:16:53 -0800, Ryan Cousineau
wrote:

In article ,
wrote:

On Fri, 25 Feb 2005 21:51:17 -0800, Ryan Cousineau
wrote:

In article ,
wrote:

Dear Ron,

The motorcycle side of the thread ended up distinguishing
"tread creep" from true sliding.

Actually breaking the tires loose from the pavement while
cornering has about the same effect on any two-wheeled
vehicle, no matter how it's powered.

Maybe this just ups the noise ratio, but the received wisdom in
motorcycle road racing is that the fastest riders really are able to
consistently slide both tires in a turn. I'm pretty sure this is
dependent on very special tires, applying major power, and abnormally
good bike-control skills.

Probably easier to just work on your climbing skills,

Dear Ryan,

Here's a link to where Mark McMaster seemed to nail the
slithery details down:

http://tinyurl.com/5ppsw

The question seemed to be whether it was a true slide (all
the rubber breaking loose) or a squirm-walk-creep-roll.

It doesn't seem to depend on terribly special tires, just
wide enough for the squirm to occur (road bicycle tires
haven't the width or the thickness of tread to do this).

Carl Fogel

I am...skeptical that squirm accounts for all of the sliding sensation
that elite motorcycle racers experience. Just so we are clear on the
vehicles in question and the nature of the tires:

http://www.cqq.ch/Moto/1Moto_images/.../GP-Vale_2.jpg
http://www.dreamgate.ne.jp/nsr/Gallery/03_gp_10.jpg

These are photos of some Italian named Rossi. I'm not sure he's any
good, since his number is 46, and not 1, and he's riding a Honda, and I
heard a Yamaha won MotoGP last year.

Those are pure slick tires, of course. Zero tread. I don't have the
engineering chops to discuss slip angles in any depth, and I readily
concede that this is moot when compared to cycling experiences, as
nobody has as much horsepower as even the most asthmatic YSR50:

[snip]

Dear Ryan,

But you do have the engineering chops to see that there are
hardly any black tire marks on the pavement in those
corners, consistent with tread squirm-roll-creep-walk, not
true sliding.

Think of the marks that the tires of cars would leave behind
while actually drifting through such corners.

Carl Fogel

Ryan Cousineau wrote:

I am...skeptical that squirm accounts for all of the sliding sensation
that elite motorcycle racers experience....

Maybe the squirm sensation comes from using excessive amounts of chamois
butter?

--
Tom Sherman - Earth

wrote:

On Sat, 26 Feb 2005 09:16:53 -0800, Ryan Cousineau
wrote:


In article ,
wrote:


On Fri, 25 Feb 2005 21:51:17 -0800, Ryan Cousineau
wrote:


In article ,
wrote:

Dear Ron,

The motorcycle side of the thread ended up distinguishing
"tread creep" from true sliding.

Actually breaking the tires loose from the pavement while
cornering has about the same effect on any two-wheeled
vehicle, no matter how it's powered.

Maybe this just ups the noise ratio, but the received wisdom in
motorcycle road racing is that the fastest riders really are able to
consistently slide both tires in a turn. I'm pretty sure this is
dependent on very special tires, applying major power, and abnormally
good bike-control skills.

Probably easier to just work on your climbing skills,

Dear Ryan,

Here's a link to where Mark McMaster seemed to nail the
slithery details down:

http://tinyurl.com/5ppsw

The question seemed to be whether it was a true slide (all
the rubber breaking loose) or a squirm-walk-creep-roll.

It doesn't seem to depend on terribly special tires, just
wide enough for the squirm to occur (road bicycle tires
haven't the width or the thickness of tread to do this).

Carl Fogel

I am...skeptical that squirm accounts for all of the sliding sensation
that elite motorcycle racers experience. Just so we are clear on the
vehicles in question and the nature of the tires:

http://www.cqq.ch/Moto/1Moto_images/.../GP-Vale_2.jpg
http://www.dreamgate.ne.jp/nsr/Gallery/03_gp_10.jpg

These are photos of some Italian named Rossi. I'm not sure he's any
good, since his number is 46, and not 1, and he's riding a Honda, and I
heard a Yamaha won MotoGP last year.

Those are pure slick tires, of course. Zero tread. I don't have the
engineering chops to discuss slip angles in any depth, and I readily
concede that this is moot when compared to cycling experiences, as
nobody has as much horsepower as even the most asthmatic YSR50:


[snip]

Dear Ryan,

But you do have the engineering chops to see that there are
hardly any black tire marks on the pavement in those
corners, consistent with tread squirm-roll-creep-walk, not
true sliding.

Think of the marks that the tires of cars would leave behind
while actually drifting through such corners.

Carl Fogel

Rossi is probably the most talented living roadracer, with a
phenomonal amount of skill. He raced and won MotoGP for Honda,
switched to Yamaha last season, to what was regarded as an
inferior bike, and won the championship his first season on it.
While Rossi is more than capable of recovering from slides, his
racing style is a fairly clean style without much drifting. Some
riders, especially those with dirt track background, drift road
racing bikes on dry tracks on a regular basis. American Nicky
Hayden used to drift bikes quite a bit, but after being a teammate
of Rossi, is finding out he can go faster by riding cleaner.
Hayden's style was mostly rear-wheel sliding, with the front end
pushing a lot and sometimes breaking loose. The rider who does the
most obvious 2-wheel drifts is probably Australian Garry McCoy. It
really takes video to see the drift, but is very obvious to anyone
who has seen it, nothing subtle about it. I think McCoy has moved
from MotoGP back to World Superbike, not having had great success
in MotoGP.

I've never seen a road bicycle drift. Sometimes a tire will break
loose on a low-traction patch (dirt, sand, etc.) and recover when
it hits clean pavement. It seems more common (judging from the pro
races OLN used to cover) for a slide to result in a very quick
low-side fall.

Dave Lehnen

On Sat, 26 Feb 2005 12:36:11 -0600, Tom Sherman wrote:

Ryan Cousineau wrote:

I am...skeptical that squirm accounts for all of the sliding sensation
that elite motorcycle racers experience....

Maybe the squirm sensation comes from using excessive amounts of chamois
butter?

Watch that talk or I'll link more MJ pictures.

Ron

RonSonic wrote:

On Sat, 26 Feb 2005 12:36:11 -0600, Tom Sherman wrote:


Ryan Cousineau wrote:


I am...skeptical that squirm accounts for all of the sliding sensation
that elite motorcycle racers experience....

Maybe the squirm sensation comes from using excessive amounts of chamois
butter?


Watch that talk or I'll link more MJ pictures.

Oh yeah, take this!
http://www.outsideconnection.com/gallant/hpv/joe/MVC-001S.JPG

--
Tom “Pre-emptive strike” Sherman - Earth

On Fri, 25 Feb 2005 03:08:05 GMT,
wrote:

Ron Sonic? writes:

It is recoverable, but not always! Pointing your wheel down the
track and speeding up is the only way out of it.

Now Jobst contended in a separate thread, on cornering on a road
course, a couple of months ago that slipping in a corner was not
something that one could recover from. It seems to me that the 2
situations are the same.

Can you reconcile this?

Yeah: Jobst was wrong. Hundreds of riders have recovered from
slides by opening out the corner. About half of them have ended up
in the ditch/hedge/barriers/crowd, but they didn't get there by
sliding :-)

Hundreds? Is this limited to say perfect clean pavement and smooth
tires or some other such rules, otherwise it would be millions. I
can't guess how many times my rear tire's added a few inches of
extra lateral motion. Hell, even caught the front trying to stutter
step a couple times.

I guess some readers need to make things up to suit their egos. The
source of this is:

http://www.sheldonbrown.com/brandt/descending.html

excerpt:

# Drifting a Road Bicycle on Pavement

# Riders have claimed they can slide a bicycle on dry pavement in
# curves to achieve greater cornering speed, as in drifting through a
# turn. A drift, in contrast to a slide, means that both wheels slip,
# which is even more difficult. This notion may come from observing
# motorcycles, that can cause a rear wheel slide by applying power
# when banked over. Besides, when questioned about how this is done,
# the proponent says that the ability was observed, done by others.

You'll notice there are qualifications about the surface this on which
occurs and it isn't with knobbies or on loose or soft surface... it's
a bicycle race track or road. I have no doubt that one can skid the
rear wheel on almost any surface and recover but causing this to
happen from tire contact (lean) angle in a turn is another matter and
the subject at hand.

Jobst Brandt


Actually, the very precise subject at hand is sliding down the banking
at the velodrome, something which usually happens to sprinters trying
to stand on the steep bit. Like any slide (including lean angle
induced slides, as in your description), it's recoverable by reducing
the sideways load before you hit the floor. At the velodrome, this
means you have to get the bike rolling down the slope, with the front
wheel below the rear (assuming, as is usually the case, that the rear
wheel was the one to break traction). As I said, the corrective action
on a road bike usually means you end up no longer on the road, the
consequences of which may be worse than completing the slide/topple,
but nonetheless the slip angle has been reduced to a negligible value
as you careen into the barriers.

As other people have noted, a bicycle cornering at high speed is
effectively an unpowered vehicle, and therefore any claims to
increased cornering speed achieved through sliding are spurious. This
is an entirely different question, though, and only peripherally
relevant to the original enquiry.

To answer Ron Sonic's query about numbers, hundreds are a subset of
millions, and I didn't want to commit myself to such a high number. I
suppose nearly every moderately serious cyclist has, at some time,
recovered from a slide, so you're probably right to say millions.


Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

"Dave Lehnen" wrote in message
news:yS6Ud.288533$w62.65856@bgtnsc05- Think of the marks that the tires of
cars would leave behind
while actually drifting through such corners.

Carl Fogel


http://images.google.com/images?q=mi...an+slide&hl=en

"Dave Lehnen" wrote in message
...
wrote:

Think of the marks that the tires of cars would leave behind
while actually drifting through such corners.

Carl Fogel

http://members.home.nl/mmschutte/1996doohan1.JPG

On Sun, 27 Feb 2005 08:24:58 -0500, "Andy Birko"
wrote:


"Dave Lehnen" wrote in message
...
wrote:

Think of the marks that the tires of cars would leave behind
while actually drifting through such corners.

Carl Fogel

http://members.home.nl/mmschutte/1996doohan1.JPG


Dear Andy,

That picture does show up--thanks for taking the trouble to
track a second version down.

I may be the credulous victim of an out-of-context snapshot,
or the front wheel may have been just about to rise off the
ground as the rear wheel accelerates, or he may have crashed
a moment later . . .

But I don't think so--that sure looks like a well-controlled
rear-wheel slide or drift under control on a paved corner to
me, with the rear wheel plainly outside the front wheel's
line and angled inward, not the mere tread-squirm that I had
in mind.

Unless someone explains otherwise, I'm wrong and Ryan and
you (and others) are right--controlled drift or slide
obviously happens on a two-wheeled vehicle on pavement.

There's even nice contrast in the picture between the
unmarked lighter pavement on the inside of the turn and the
darker pavement where the tires are skidding.

Rub my nose in this one as often as needed.

Thanks again,

Carl Fogel