Kawasaki Motorcycle Forums banner

Status
Not open for further replies.
1 - 14 of 14 Posts

·
Registered
Joined
·
451 Posts
Discussion Starter #1
I was wondering if there were any good pages that explain the "reasoning" as to why a bike can damn near lay parallel with the road and not hop accross it sideways.. I know it DOESN'T.. I just want to be taught how and why it's possible..

You would just think that since all the weight is being pressed sideways that you would have no more help from gravity holding you down on the street..

I dunno, just a lot of bike riding goes against common sense (ie if you want to turn right, push the opposite way, stuff like that)..

Thanks ahead of time for the input.
 

·
Registered
Joined
·
129 Posts
its all physics. as you are going through a corner, weight is transfered via the momentum of the bike, which in turn 'pulls it down' and as long as the tires keep their traction the weight will be channelled down through the tires keeping the bike up. its a bit tricky to explain, but you further help you get the idea, take a cup full of water in your hand, hold it from above with your fingers and start to spin, slowly raising your arm, if you keep doing this and keep a good spin rate you can hold your arm straight out without the water spilling out, same idea roughly.
 

·
Registered
Joined
·
451 Posts
Discussion Starter #5
Wow, didn't expect such quick replies :)

I was gonna google when I got home tonight (just started thinking about this at work today), but I wanted to see if anybody had some good resources, first.

Thanks again, guys.

Any more help would be appreciated, you can never be too edumacated :D
 

·
Registered
Joined
·
178 Posts
centripetal force (Fc=m*v^2/r) acts in the radial direction, and gravitionanl force (Fg=m*g) still works pulling you down. each provides an effective torque at the center of mass about the pivot point where the tires touch the ground. this torque balance is what keeps you suspended while leaning over in a turn. or rather, you lean over accordingly so as to change the effective lever arm that each force acts over, which balances the forces. hence the higher the speed, the greater the centripetal force, the more you need to lean the bike over.
friction between the tires is a function the force pushing down on the tires and the coefficient of friction between your tires and the tarmac. as long as the only thing touching the ground is your tires, you still have all of your and the bike's weight pushing down to provide friction. that frictional force (Ffric=mu*m*g) pushes inward toward the center of the turn while the centripetal force is trying to push out.
 

·
Registered
Joined
·
451 Posts
Discussion Starter #8
Originally posted by jmart
centripetal force (Fc=m*v^2/r) acts in the radial direction, and gravitionanl force (Fg=m*g) still works pulling you down. each provides an effective torque at the center of mass about the pivot point where the tires touch the ground. this torque balance is what keeps you suspended while leaning over in a turn. or rather, you lean over accordingly so as to change the effective lever arm that each force acts over, which balances the forces. hence the higher the speed, the greater the centripetal force, the more you need to lean the bike over.
friction between the tires is a function the force pushing down on the tires and the coefficient of friction between your tires and the tarmac. as long as the only thing touching the ground is your tires, you still have all of your and the bike's weight pushing down to provide friction. that frictional force (Ffric=mu*m*g) pushes inward toward the center of the turn while the centripetal force is trying to push out.
Very interesting. This is what I was looking for. That's more specific and the website is represented more in plain english. Thanks for all the information, guys. I knew I'd get a good outcome asking this question here [8D]
 

·
Registered
Joined
·
532 Posts
ever played with a gyro?...worth the 5 buck at a science or school supply store...play with that and you will understand...two wheel and a crankshaft makes excelent gyros. thats why burnout are possible with no feet on the ground.. play with a gryo...and not the greek sandwich
 

·
Registered
Joined
·
1,100 Posts
Also, if you really look, it's pretty rare to see a bike at more than a 45 deg angle to the road. The main thing that keep the bike from skittering off the road is gravity, but it's helped by a properly tuned suspension, and a rider keeping his (or her) mass in the proper place.
 

·
Registered
Joined
·
178 Posts
I forgot to add that roads are banked in order to take advantage of the centripetal force to push you harder into the road.
 

·
Registered
Joined
·
2,042 Posts
Originally posted by ifgshooter
Kinda reminds me of this pic I found awhile back of Rossi. The difference between winning & losing.
While the pic looks nice, lean angle or midcorner speed is far from the most important phase in going fast.
 
1 - 14 of 14 Posts
Status
Not open for further replies.
Top