Counter-steering physics 101

[zedsaid]

https://carnot.physics.buffalo.edu/archives/1997/01_1997/msg00016.html

Countersteering physics 101.


An over-most-heads explanation of the technique, and how it actually works.

[Speeddog]

That's a good one. 

[ScottRNelson]

I disagree with the explanation.

It implies that gyroscopic forces lean the bike, while those only play a very small part in getting a motorcycle to turn.  When you push on the inside bar to get the bike to start turning, the wheel turns slightly towards the outside of the turn, pulling the tires towards the outside while the bike rotates about its center of gravity.  But steering geometry (rake and trail) very quickly causes the front wheel to get back in line and steers around the turn to balance the lean.

This works on a motorcycle with a ski on the front and no front wheel at all, with no gyroscopic forces to help lean the bike, and it feels very much the same as with a front wheel there turning the bike.

[zedsaid]

I disagree with the explanation.

I remember the "turn a spinning wheel" lesson from physics, and it's a pretty tough thing to ignore.  I  don't have any expectations as to the gyroscopic effect maintaining the turn, but it has to have something to do with  initiating it.

I think this is the type of thing the Mythbusters would have a field day with.  The trick is, how do we phrase it in the form of a myth to be tested?

[Adamm0621]

Since I still have a while until I can get another motorcycle, and my only means of transportation is a bicycle, I've been practicing my riding techniques, i.e. counter-steering, looking through turns, riding on sidewalks... the usual.  I was working on my counter-steering the other day and nearly ate it.  I forgot that on a bike with pedals if you counter-steer into a hard turn where you're leaning pretty far over, if you continue to pedal to maintain speed or increase it after the apex, you're going to drag a pedal, shoe, and possibly your calf.  Luckily I didn't crash, and I arrived at work fully awake.  [moto]

[zedsaid]

Since I still have a while until I can get another motorcycle, and my only means of transportation is a bicycle, I've been practicing my riding techniques, i.e. counter-steering, looking through turns, riding on sidewalks... the usual.  I was working on my counter-steering the other day and nearly ate it.  I forgot that on a bike with pedals if you counter-steer into a hard turn where you're leaning pretty far over, if you continue to pedal to maintain speed or increase it after the apex, you're going to drag a pedal, shoe, and possibly your calf.  Luckily I didn't crash, and I arrived at work fully awake.  [moto]

How far can you lean while pedaling?

[Statler]

I'm with Scott.

very light wheels with less gyroscopic effect let the bike turn much faster.  why?   it's easier to turn them so it's faster to get them out to the side while the center mass of the bike keeps going straight, thus "falling" over to the side over the front wheel now off center.

gyroscopic effect of the wheels do more to keep it from turning than making the bike lean....yes, if you turn the wheel left it will lean right...we all did the bicycle wheel in our hands thing in school...but on a motorcycle the faster the wheel can be turned the faster the bike will lean over (all other things equal).

[Popeye the Sailor]

That is one of the most obtuse, poorly written pieces of engineering I've ever seen.

[He Man]

that was pretty bad. there is a video of it on youtube. he puts a camera on the floor and ride towards it slowly tuning his bar left and right, and you can see how the bike dips.

[triangleforge]

How far can you lean while pedaling?

Pretty far, but ride a fixed gear bike enough and you'll discover it's not much fun to clip a pedal, usually two or three times in quick succession, and feel the rear wheel lift and sidestep about a foot to the outside of the turn.

Wait a minute -- that IS a lot of fun!!!

[Triple J]

I'm with Scott & Statler.

[He Man]

I'm with Scott & Statler.

Sounds like a lawfirm. 

Statler, arent you a lawyer?

[aaronb]

im on the 'that guy sucks' wagon as well.  he is really trying to over think things while ignoring some basic concepts

[duc996]

For some reason i can't view it.

[Latinbalar]

For the Mythbusters fans:

A motorcycle turns using Gyro scopic forces.....or does it?

Thats how you should word it.

You should also recomend that they use me for the test rider