The 1G Club - By Keith Code

[Motofool]

"Once we become comfortable with 45 degrees and attempt to go beyond that, the process begins to reverse. Immediately we have more lateral load than vertical load, and things begin to heat up. Riders apparently have difficulty organizing this. Suddenly, we are thrust into a sideways world where the forces escalate rapidly. While it takes 45 degrees to achieve 1g lateral, it takes only 15 degrees more to experience nearly double that (depending on rider position and tire size)."

http://www.motorcyclistonline.com/ne...ning_the_bike/

[csmith12]

I would like to see the same graph with speed and grip factored in.

[alex.s]

i think speed might be irrelevant... because the weight of the rider and the bike is (relatively) fixed, the lean angle is proportional to the centrifugal force (outward force caused by inertia) so if you were going 10mph at 45degrees lean angle, you would experience the same centrifugal force (1G) as you would at 100mph at 45 degrees lean angle (1G), the difference would be how much that 45 degrees actually gets you (you would be running a much wider line)

[rojoracing53]

I think us riders in the superbike class at Daytona get easily over 1g on the banks and I know my dad used to get light headed when he raced there.

[Alex]

Yup - I think it's much higher than even that. All of the Daytona tire testing makes reference to the bike putting twice the normal load into the tires on the banking, requiring those extra-stiff sidewalls to keep from destroying themselves. Which would imply 2+ G, depending on how it's measured. Jason - doesn't your upper body / helmet feel twice as heavy and yanked down to the tank while at speed there?

[rojoracing53]

Originally Posted by Alex

Yup - I think it's much higher than even that. All of the Daytona tire testing makes reference to the bike putting twice the normal load into the tires on the banking, requiring those extra-stiff sidewalls to keep from destroying themselves. Which would imply 2+ G, depending on how it's measured. Jason - doesn't your upper body / helmet feel twice as heavy and yanked down to the tank while at speed there?

Yes it's a very odd feeling but you really do feel like you at least twice as heavy but your laying on the tank so you don't have to hold up the wieght on your own. But if you lose your windscreen then even the G's won't be enough to keep the wind from trying to tear you off the bike, ask me how I know

[ai4px]

Originally Posted by Motofool

http://www.motorcyclistonline.com/ne...ning_the_bike/

Looks like TANgent to me....

[CC Cowboy]

Originally Posted by rojoracing53

Yes it's a very odd feeling but you really do feel like you at least twice as heavy but your laying on the tank so you don't have to hold up the wieght on your own. But if you lose your windscreen then even the G's won't be enough to keep the wind from trying to tear you off the bike, ask me how I know

I remember the old track pounding your chest on the banking from a few dips in the track. It was like someone punching you in the chest lap after lap. I used to put some foam in my leathers but I would still be sore. The new track (repaved) is silky smooth and much faster.

[Misti]

Just an FYI, Twist of the Wrist is being released shortly as an eBook by Amazon and other eBook retailers....soon

[Alex]

It's been so easily available electronically via some less than legitimate methods, I'm happy that it is now going to be easily accessible in a way that fairly compensates Keith and his team. I hope it is successful.

[Motofool]

Originally Posted by Alex

Yup - I think it's much higher than even that. All of the Daytona tire testing makes reference to the bike putting twice the normal load into the tires on the banking, requiring those extra-stiff sidewalls to keep from destroying themselves. Which would imply 2+ G, depending on how it's measured.

Originally Posted by rojoracing53

Yes it's a very odd feeling but you really do feel like you at least twice as heavy but your laying on the tank so you don't have to hold up the wieght on your own.

Originally Posted by CC Cowboy

I remember the old track pounding your chest on the banking from a few dips in the track. It was like someone punching you in the chest lap after lap. I used to put some foam in my leathers but I would still be sore. The new track (repaved) is silky smooth and much faster.

Note that the graph of post #1 shows only the lateral G, which is what tries to skid the tires.

What the rider feels on his body (against seat, tank, pegs and grips) is higher than that, which would be the total or real G.

Regarding maximum attainable grip, that should be proportional to the weight of the bike plus rider before they start moving and proportional also to the tires' contact patches.

That weight is the mass of both combined with the vertical G, which oscillates around the natural gravity (g) while the bike rolls over the irregularities of the pavement (hence, the "track pounding your chest" feeling).
After a crest G<g (the bike+rider are moving down and weight less = less friction or traction on the contact patch to fight the lateral G).
After a valley G>g (the bike+rider are moving up and weight more = more friction or traction on the contact patch).

Some tires have a bigger contact patch as they lean.
After several laps of a fast race, the rubber on the sides starts deteriorating, which may cancel the gain in area of the contact patch.

See these schematics:

http://forums.superbikeschool.com/in...=40#entry26802

[alex.s]

so the actual felt effect on the rider on the high bank is around 3Gs? you start to pass out around 5Gs right?

[Motofool]

This article is not specific about the 5g, other than is the typical maximum under-heavy-braking for Formula One car, but it explains that passing out depends of physical condition:

http://en.wikipedia.org/wiki/G-force

[Motofool]

Originally Posted by csmith12

I would like to see the same graph with speed and grip factored in.

[alex.s]

i'm kinda confused by that graph... regarding speed...

also what about acceleration force? 40/60 is .2G you said, right? is that what the bike speed line represents?

[Motofool]

Yes, it is confusing seeing that distorted line.

Our senses are familiar with a fix radius turn that we take at different speeds, while they are not familiar with minute lean angle readings.

Also, in our world, speed always increases and decreases at a steady rate when we are accelerating or braking.

If we could measure the lean angle while our bikes are speeding up or slowing down at a steady rate, we could see that the angle does not change at a steady rate.

No, the 40/60 weight distribution and the 0.2g acceleration is not included in the graph.
Only what is happening in the lateral world (plane perpendicular to the forward movement of the bike).

[bdavison]

Cool, I put a G-meter on my bike with a data logger, and a 45 deg feeler stick on the foot pegs...and took a ride in the twisties....pretty dang accurate chart. Speed didnt seem to be much of a factor, +/-.3g, which is probably just the accuracy level of my g-meter or lean angle.

[Rexbo]

how about lean angle vs ass clench.

I call not it for measuring the 2nd one.

[csmith12]

One might be able to buy a "device" capable of measuring said "clench" from here.

[rojoracing53]

Originally Posted by csmith12

One might be able to buy a "device" capable of measuring said "clench" from here.

Will this interface with me current data acuisition program?

[Alex]

Originally Posted by csmith12

One might be able to buy a "device" capable of measuring said "clench" from here.

[ninja250r81]

throw a spanner in the works

a few can-am clubs popping up down under. http://www.can-am.brp.com/

their g force should be calculated like a car??

[Motofool]

Some serious expertise in said "clench" has been exposed here.

My advice would be as about tensing the arms: just relax and let it enter..........the curve.

[csmith12]

lol..... **** has hit the fan now....

[Motofool]

Originally Posted by Motofool

"Once we become comfortable with 45 degrees and attempt to go beyond that, the process begins to reverse."

If we could measure the lean angle while our bikes are speeding up or slowing down at a steady rate, we could see that the angle does not change at a steady rate.

[Motofool]

Another one.

We are seeing a frontal view of the bike and rider.

The red arc represents how the top of the bike moves along the whole range of leaning, the 0.0 point represents the tires' contact patch.

Note that, for steadily increasing speed, the higher variation of lean angle happens around 45 degrees (~55 mph).

Same thing, different presentation:

[csmith12]

I always had a gut feeling... but now I got confirmation. Seems I like to spend alot of time near 1g too.

I am really digging decent telemetry.

[sharky nrk]

^^ that telemetry and data acq is pretty sweet

[Motofool]

Original related article is in German; this is a Google translation:

https://translate.googleusercontent....2chDRL5vcWrnGQ

[SLOWn60]

Lol! You got me Hernan!
Sorry @Misti & @Alex: I must remember to check the date of posts before interacting with them!

[cbinker]

Makes me wonder what kind of G-forces i was experiencing when i crashed in the bowl at chuckwalla.

[Motofool]

Originally Posted by cbinker

Makes me wonder what kind of G-forces i was experiencing when i crashed in the bowl at chuckwalla.

Perhaps up to 20 or 25 times the force of your weight while standing still (g=1).

Look for "Human tolerance" and "Typical examples" here:
https://en.m.wikipedia.org/wiki/G-force

[Alex]

Originally Posted by cbinker

Makes me wonder what kind of G-forces i was experiencing when i crashed in the bowl at chuckwalla.

I'd imagine you experienced quite a few G-related forces and exclamations while flying through the air:

"Gadzooks, goddammit, gee whiz, goodness, good grief, gosh, goodbye"

[cbinker]

Originally Posted by Alex

I'd imagine you experienced quite a few G-related forces and exclamations while flying through the air:

"Gadzooks, goddammit, gee whiz, goodness, good grief, gosh, goodbye"

i lost the front end on the 250 pinned in 6th. I blacked out and the next thing i remember was sliding at the top of the track, then i hit the dirt and started tumbling.

[Misti]

Originally Posted by cbinker

i lost the front end on the 250 pinned in 6th. I blacked out and the next thing i remember was sliding at the top of the track, then i hit the dirt and started tumbling.

Doh, that doesn't sound fun....