Leaning

[Skyryder]

I got as far as the bvroom stick then I fell off.


Skyryder

[Motu]

The C of G goes through the contact patch of the tyre,a wide tyre needs the CG to shift inwards as the bike leans over,and actualy a bike with a low CG needs to be leaned over further with a wide tyre.Tony Foale has an excelent diagram and explanation in his book Motorcycle Chassis Design.

I ride a variety of bikes and use many different riding styles to get around - sometimes I move to the inside of the bike,sometimes I push the bike down and lean out.Trials riders and to some extent enduro and MX riders shift their weight to the outside of the bike in a turn....a road racer will hang off the inside of the bike,but weight the outside peg...same thing,going about it different ways.

[John]

As said - better than listening to us talk about gyroscopic forces and gravity enduced forces, just go do a course much less complicated and more practical (not bashing previous posts mind you! very good stuff)

[ridespy]

There isn't any such force. My 7th form Physics tutor took great pains to enforce that and had successfully challenged exam questions that contained the word centrifugal. Centripetal force describes a force being generated to prevent an object moving in a straight line. The object wants to travel at a tangent to the arc your a setting it on through other forces. A slightly more simple example than a motorcycle is a sling.

Well you are right and wrong, You can use the word centrifugal and in physics you can use and calculate centrifugal force in a formula, (IE Fc = mv2/r, where Fc = centrifugal force, m = mass, v = speed, and r = radius. ) but yes the force doesn't exist. Its just like the number zero it doesn't exist either but we use it every day.

An object traveling in a circle behaves as if it is experiencing an outward force. This force is known as the centrifugal force. But centrifugal force does not actually exist. Nevertheless, it appears quite real to the object being rotated. For instance, a person on a play ground round about is not experiencing any real force outward, but they must exert a force inwards to keep from flying off the merry-go-round. The person believes that they are in an inertial frame of reference, when in fact they are is not. An object traveling in a circular motion is constantly accelerating and is therefore never in an inertial frame of reference. Since the centrifugal force appears so real, but in fact it is not real, but can still be used.

So in summing up Centripetal force is a real force and Centrifugal force is perceived effect of Centripetal force.

If you don't believe me, feel free to drop steven hawkings an email and ask him

[James Deuce]

If you don't believe me, feel free to drop steven hawkings an email and ask him

I'd be quite happy too, and I am sure that he would agree that centrifugal force is a convenient term coined by technicians, not scientists. As for zero not existing, the zero concept was pivotal in human development. Without it very little of what we consider "modernity" is possible.

There is no such thing as centrifugal force, just as there is no such thing as "US English". Both are convenient adjectives for an inability to use a tool correctly.

[justsomeguy]

Just go out and ride for now and on the 19th of June it will all be explained in detail until you understand it .

[sAsLEX]

Well you are right and wrong, You can use the word centrifugal and in physics you can use and calculate centrifugal force in a formula, (IE Fc = mv2/r, where Fc = centrifugal force, m = mass, v = speed, and r = radius. ) but yes the force doesn't exist. Its just like the number zero it doesn't exist either but we use it every day.

yip the c in your formula stands for centripetal, not centrifugal.

look here for good info to confuse http://hyperphysics.phy-astr.gsu.edu/hbase/cf.html#cf

[Ixion]

In 40 odd years of riding I've never figured out the why of leaning. Always just get confused. just seem to find what works and do it. On road, lean with the bike, straight line through the rear wheel and up your legs and back. For emergencies scunch off the bike on the downside. Off road, hang off the bike the other way. Sometimes. Damn if I know when though. And sidecar's different again. And slow turns on road is like off road.

It's all damn confusing, easiest just to go out and do it.

[John]

Yup best way to learn is to get out there - you will find everything pretty much automatic - minds are amazing things..

[James Deuce]

minds are amazing things..

If you've got one.

I've half a mind

[pyrocam]

hmm.

first let me say for those of you havent seen my 'wafer thin' tyres. I have the tiniest tyres ive ever seen on a bike. almost chunky pushbike wheels.

ok to the point of 'what feels right;
I feel right doing image 1 of my first post. Im only doing slow (30-60k) turns on an even surface (fucking around while I commute) and it 'FEELS' like I should be on top of the bike. Ive been riding pushbikes long distances and I used to commute through central auckland at rush hour on one and perhaps sometimes a slight lean was in order

am I right in guessing that.
If I am going around a corner on my biscuit tires a low (30-60k) if it feels right I should be as perpendicular to the ground as I feel comfortable with (as in, what feels 'right') but if I were to particapate in a high speed track situation then perhaps a 'lean with the bike' situation might be more in order.

at the moment. I can drive straight with the bike at maybe 15 degree's and myself perfectly straight. and if I want to go around a corner the the bike handles better while on that 15 degree angle but it feels safer with gravity effect pushing down to the earth (therefore pushing the wheel onto the road) than pushing my weight sideways to the road?

[John]

hmm.

first let me say for those of you havent seen my 'wafer thin' tyres. I have the tiniest tyres ive ever seen on a bike. almost chunky pushbike wheels.

ok to the point of 'what feels right;
I feel right doing image 1 of my first post. Im only doing slow (30-60k) turns on an even surface (fucking around while I commute) and it 'FEELS' like I should be on top of the bike. Ive been riding pushbikes long distances and I used to commute through central auckland at rush hour on one and perhaps sometimes a slight lean was in order

am I right in guessing that.
If I am going around a corner on my biscuit tires a low (30-60k) if it feels right I should be as perpendicular to the ground as I feel comfortable with (as in, what feels 'right') but if I were to particapate in a high speed track situation then perhaps a 'lean with the bike' situation might be more in order.

at the moment. I can drive straight with the bike at maybe 15 degree's and myself perfectly straight. and if I want to go around a corner the the bike handles better while on that 15 degree angle but it feels safer with gravity effect pushing down to the earth (therefore pushing the wheel onto the road) than pushing my weight sideways to the road?

Just a point - tire size means nothing at ALL, big bikes just need more tire space to hold the torque to the ground, the smaller the better in practicality.

On another note, dont try so hard, sounds like your trying to understand more than you can comprehend at the moment...

[justsomeguy]

Well PYRO the easiest way to do this is find a set of corners you know well and practice riding them.

Try different stances and positions. I feel a more hanging off style is called for while riding your bike due to your 100 width rear tyres.

Practice makes anything easier.

[pyrocam]

Well PYRO the easiest way to do this is find a set of corners you know well and practice riding them.

Try different stances and positions. I feel a more hanging off style is called for while riding your bike due to your 100 width rear tyres.

Practice makes anything easier.

I do. I only play around with this stuff on corners I know like the back of me hand. considering Im comuting Im only doing stuff on 90 degree turns but I have a fair bit of leeway.

so. if the size of my tires doesnt matter. then
the big question is. how low can I go.

I can get at most 40 degrees (from my POV) if im fully suited up and keen (+dry weather and grippy road etc)

Bugjuice has said that I can 'lean the crap' out of my tires (btw not his actual words)

I feel that on normal city roads when im not going so fast. im quite alright to go perpendicular to the road (like first post image 1) because it feels right and im not going too fast. but if i was on a corner that has its own lean built in (like a good 22 corner or a track corner) the I could lean the crap out of it and it would slide off into the distance.

I think the 2 things that bother me are
shouldnt the bike slide out if I lean too much into a corner
I dont have the riding experience to try lean the crap out of corner.

[John]

If your hitting the limits of the tire you will feel the back sliding about, just lift it a little and lean off the bike, and your sweet - I dont think you will have to worry about 'overleaning' at this point, ask ts to tip you out if your real keen on getting on the limits.