Traction

We got 12" of wet, dense snow today, but the plows came out, and the
roads aren't terrible, despite a bit of slush and some snowy patches. So
this evening, when I had to pick up a prescription at the local
pharmacy, I flicked on the dynohub headlight & taillight and rode to the
pharmacy and back. As I did so, I noticed a reflex retained from my
teenage years of winter newspaper delivery by bicycle.

When I'm making a turn on a surface that is, or might be, very slippery,
of course I slow down. But I also reflexively make an effort to keep
the bike vertical. To balance, I lean my body inward from the bike.

Obviously, the center of gravity of my body+bike must be a bit inward
(i.e. toward the center of the curve) for balance and stability. The
amount the c.g. is inward is a simple function of speed and radius of
turn. But in dry conditions, I achieve this by tilting the bike while
keeping my body in the normal position relative to the bike. In
slippery conditions, I do it instead by leaning my body away from the bike.

Do others do this? If so, why?

To achieve a certain lateral acceleration (or sharpness of turn), the
amount of lateral friction force (or traction) is fixed. And I don't
think there's any great difference in friction coefficient for my
Paselas when they're vertical vs. tilted, so the likelihood of a skid
shouldn't be much different. Psychologically, it _feels_ like some sort
of secondary effect - as if I have a better chance of stopping the
slide, or catching the bike, or just not falling, if the bike is vertical.

Maybe this is a valuable reflex I picked up by trial and error in my
paperboy days. Or maybe it's some unconscious superstition. At my age,
I'm a bit afraid to do an A-B test to see.

So: Comments?


--
- Frank Krygowski

I did it on the ice 10 weeks ago and broke my hip if you remember so be
careful. I am happy to report I am back to riding outside if I want when the
weather gets better but even to my surprise I started back running a week
ago easy. Have run 5.5 miles past two days on the treadmill.

But if I were you given my experience with ice just stay on the trainer.


Deacon mark cleary

"Frank Krygowski" wrote in message ...

We got 12" of wet, dense snow today, but the plows came out, and the
roads aren't terrible, despite a bit of slush and some snowy patches. So
this evening, when I had to pick up a prescription at the local
pharmacy, I flicked on the dynohub headlight & taillight and rode to the
pharmacy and back. As I did so, I noticed a reflex retained from my
teenage years of winter newspaper delivery by bicycle.

When I'm making a turn on a surface that is, or might be, very slippery,
of course I slow down. But I also reflexively make an effort to keep
the bike vertical. To balance, I lean my body inward from the bike.

Obviously, the center of gravity of my body+bike must be a bit inward
(i.e. toward the center of the curve) for balance and stability. The
amount the c.g. is inward is a simple function of speed and radius of
turn. But in dry conditions, I achieve this by tilting the bike while
keeping my body in the normal position relative to the bike. In
slippery conditions, I do it instead by leaning my body away from the bike.

Do others do this? If so, why?

To achieve a certain lateral acceleration (or sharpness of turn), the
amount of lateral friction force (or traction) is fixed. And I don't
think there's any great difference in friction coefficient for my
Paselas when they're vertical vs. tilted, so the likelihood of a skid
shouldn't be much different. Psychologically, it _feels_ like some sort
of secondary effect - as if I have a better chance of stopping the
slide, or catching the bike, or just not falling, if the bike is vertical.

Maybe this is a valuable reflex I picked up by trial and error in my
paperboy days. Or maybe it's some unconscious superstition. At my age,
I'm a bit afraid to do an A-B test to see.

So: Comments?


--
- Frank Krygowski

you taught engineering n have a degree ?

On Tue, 16 Feb 2016 19:34:40 -0500, Frank Krygowski
wrote:

We got 12" of wet, dense snow today, but the plows came out, and the
roads aren't terrible, despite a bit of slush and some snowy patches. So
this evening, when I had to pick up a prescription at the local
pharmacy, I flicked on the dynohub headlight & taillight and rode to the
pharmacy and back. As I did so, I noticed a reflex retained from my
teenage years of winter newspaper delivery by bicycle.

When I'm making a turn on a surface that is, or might be, very slippery,
of course I slow down. But I also reflexively make an effort to keep
the bike vertical. To balance, I lean my body inward from the bike.

Obviously, the center of gravity of my body+bike must be a bit inward
(i.e. toward the center of the curve) for balance and stability. The
amount the c.g. is inward is a simple function of speed and radius of
turn. But in dry conditions, I achieve this by tilting the bike while
keeping my body in the normal position relative to the bike. In
slippery conditions, I do it instead by leaning my body away from the bike.

Do others do this? If so, why?

To achieve a certain lateral acceleration (or sharpness of turn), the
amount of lateral friction force (or traction) is fixed. And I don't
think there's any great difference in friction coefficient for my
Paselas when they're vertical vs. tilted, so the likelihood of a skid
shouldn't be much different. Psychologically, it _feels_ like some sort
of secondary effect - as if I have a better chance of stopping the
slide, or catching the bike, or just not falling, if the bike is vertical.

Maybe this is a valuable reflex I picked up by trial and error in my
paperboy days. Or maybe it's some unconscious superstition. At my age,
I'm a bit afraid to do an A-B test to see.

So: Comments?

I think that turning while keeping the bike vertical, i.e., by simply
turning the handle bars, is probably how most kids who are first
learning to ride turn and usually they fall over a few times before
they learn to lean the bike.

But, on the other hand if either the front or rear wheel skid one
automatically, it seems, compensate by trying to move the CG toward
the outside of the turn, in the direction of the skid. If on foot
slips and slides happen very quickly and it is hard to remember what
one did but if skating one tends to do the same thing throw one's
weight in the direction of the skid to try and stay vertical.
--
cheers,

John B.

On 17/02/16 01:34, Frank Krygowski wrote:
We got 12" of wet, dense snow today, but the plows came out, and the
roads aren't terrible, despite a bit of slush and some snowy patches. So
this evening, when I had to pick up a prescription at the local
pharmacy, I flicked on the dynohub headlight & taillight and rode to the
pharmacy and back. As I did so, I noticed a reflex retained from my
teenage years of winter newspaper delivery by bicycle.

When I'm making a turn on a surface that is, or might be, very slippery,
of course I slow down. But I also reflexively make an effort to keep
the bike vertical. To balance, I lean my body inward from the bike.

Obviously, the center of gravity of my body+bike must be a bit inward
(i.e. toward the center of the curve) for balance and stability. The
amount the c.g. is inward is a simple function of speed and radius of
turn. But in dry conditions, I achieve this by tilting the bike while
keeping my body in the normal position relative to the bike. In
slippery conditions, I do it instead by leaning my body away from the bike.

Do others do this? If so, why?

Yep. Makes me feel like a Motorcycle Grand Prix racer.

To achieve a certain lateral acceleration (or sharpness of turn), the
amount of lateral friction force (or traction) is fixed. And I don't
think there's any great difference in friction coefficient for my
Paselas when they're vertical vs. tilted, so the likelihood of a skid
shouldn't be much different. Psychologically, it _feels_ like some sort
of secondary effect - as if I have a better chance of stopping the
slide, or catching the bike, or just not falling, if the bike is vertical.

I *think* it gives a small margin. With the normal turn the CoG, point
of lateral resistance (CoLR) are in a plane, if the CoLR moves outwards,
out of plane, the CoG is now helping it move further out of plane. If
you hang off, you get a few inches while the *opposite* is happening.

Just my tuppence worth.

Maybe this is a valuable reflex I picked up by trial and error in my
paperboy days. Or maybe it's some unconscious superstition. At my age,
I'm a bit afraid to do an A-B test to see.

So: Comments?

Jobst Brandt addressed the question of bicycle/rider angle and traction in one of his short FAQ pieces. Try Google. I'm not so sure there's anything to add to what he wrote.

Andre Jute
Now let us praise famous men -- Ecclesiastes

On Wednesday, February 17, 2016 at 5:17:56 AM UTC-5, Andre Jute wrote:
Jobst Brandt addressed the question of bicycle/rider angle and traction in one of his short FAQ pieces. Try Google. I'm not so sure there's anything to add to what he wrote.

Andre Jute
Now let us praise famous men -- Ecclesiastes

COUNTERSTEERING, AND LEANING WEIGHT FORWARD FOR FRONT WHEEL TRACTION REDUCES FRONT WHEEL TURNING FOR ALL TURNS IN THAT FRONT WHEEL DOESN'T TURN AS MUCH.
TURNING A WHEEL FROM THE PREVIOUS PATH REDUCES GRIP: NEWTON

AND NOT COUNTERSTEERING REDUCES CONTACT SURFACE.


NOT COUNTERSTEERING REDUCES SECONDARY MOTIONS POTENTIALS INSIDE THE NOW TURNING WHEEL...ALL ADDITIVE FROM YAW FORCES OUTSIDE THE PREVIOUS PATH. INCREASING DISTORTION OF CONTACT PATCH.

On 2/16/2016 6:34 PM, Frank Krygowski wrote:
We got 12" of wet, dense snow today, but the plows came out,
and the roads aren't terrible, despite a bit of slush and
some snowy patches. So this evening, when I had to pick up a
prescription at the local pharmacy, I flicked on the dynohub
headlight & taillight and rode to the pharmacy and back. As
I did so, I noticed a reflex retained from my teenage years
of winter newspaper delivery by bicycle.

When I'm making a turn on a surface that is, or might be,
very slippery, of course I slow down. But I also
reflexively make an effort to keep the bike vertical. To
balance, I lean my body inward from the bike.

Obviously, the center of gravity of my body+bike must be a
bit inward (i.e. toward the center of the curve) for balance
and stability. The amount the c.g. is inward is a simple
function of speed and radius of turn. But in dry
conditions, I achieve this by tilting the bike while keeping
my body in the normal position relative to the bike. In
slippery conditions, I do it instead by leaning my body away
from the bike.

Do others do this? If so, why?

To achieve a certain lateral acceleration (or sharpness of
turn), the amount of lateral friction force (or traction) is
fixed. And I don't think there's any great difference in
friction coefficient for my Paselas when they're vertical
vs. tilted, so the likelihood of a skid shouldn't be much
different. Psychologically, it _feels_ like some sort of
secondary effect - as if I have a better chance of stopping
the slide, or catching the bike, or just not falling, if the
bike is vertical.

Maybe this is a valuable reflex I picked up by trial and
error in my paperboy days. Or maybe it's some unconscious
superstition. At my age, I'm a bit afraid to do an A-B test
to see.

So: Comments?



Yes, I've noticed that; one intuitively tends to keep the
bike more vertical where there are traction losses like
ice/snow. Maybe for faster correction to front slip?

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 2/17/2016 5:13 AM, AMuzi wrote:
On 2/16/2016 6:34 PM, Frank Krygowski wrote:
We got 12" of wet, dense snow today, but the plows came out,
and the roads aren't terrible, despite a bit of slush and
some snowy patches. So this evening, when I had to pick up a
prescription at the local pharmacy, I flicked on the dynohub
headlight & taillight and rode to the pharmacy and back. As
I did so, I noticed a reflex retained from my teenage years
of winter newspaper delivery by bicycle.

When I'm making a turn on a surface that is, or might be,
very slippery, of course I slow down. But I also
reflexively make an effort to keep the bike vertical. To
balance, I lean my body inward from the bike.

Obviously, the center of gravity of my body+bike must be a
bit inward (i.e. toward the center of the curve) for balance
and stability. The amount the c.g. is inward is a simple
function of speed and radius of turn. But in dry
conditions, I achieve this by tilting the bike while keeping
my body in the normal position relative to the bike. In
slippery conditions, I do it instead by leaning my body away
from the bike.

Do others do this? If so, why?

To achieve a certain lateral acceleration (or sharpness of
turn), the amount of lateral friction force (or traction) is
fixed. And I don't think there's any great difference in
friction coefficient for my Paselas when they're vertical
vs. tilted, so the likelihood of a skid shouldn't be much
different. Psychologically, it _feels_ like some sort of
secondary effect - as if I have a better chance of stopping
the slide, or catching the bike, or just not falling, if the
bike is vertical.

Maybe this is a valuable reflex I picked up by trial and
error in my paperboy days. Or maybe it's some unconscious
superstition. At my age, I'm a bit afraid to do an A-B test
to see.

So: Comments?



Yes, I've noticed that; one intuitively tends to keep the bike more
vertical where there are traction losses like ice/snow. Maybe for faster
correction to front slip?

Obviously he needs a two wheel drive or AWD bicycle for these conditions.

For your reference, records indicate that
Frank Krygowski wrote:

Do others do this? If so, why?

I like to keep my body weight as dynamic as possible when riding over
questionable surfaces. When riding in snow, even along a straight line,
my experience tells me that I’m going to be better able to man-handle
the machine to keep it upright if I don’t have all my weight dead on the
seat.

Psychologically, it _feels_ like some sort
of secondary effect - as if I have a better chance of stopping the
slide, or catching the bike, or just not falling, if the bike is vertical.

This may be part of the reason I do it, too, but it may also have a physical basis. A bike that is farther from vertical seems like it will not *regain* traction as easily as one that is near vertical. And if a point of contact
starts to slide, I don’t expect recovery is going to be very possible if I
am stuck with the tilt+gravity adding energy to the problem.

--
"Also . . . I can kill you with my brain."
River Tam, Trash, Firefly