On the average motorcycle, how many degrees do the handlebars turn, lock-to-lock?
I’ve never bothered to find out. The reason is that at cruising speed you don’t actually steer the bike. You countersteer it. That is, if you want to turn right you press forward on the right bar. This would seem to turn the wheel to the left and make a left turn, but it doesn’t. It makes the bike lean to the right, so you go right.
The reason for this is gyroscopic precession. Precession is a phenomenon whereby a force applied to a spinning mass (such as a motorcycle tyre or a helicopter rotor system) will manifest itself 90° in the direction of rotation.
Let’s go back to the right turn. You press on the right handlebar. This pressure is transmitted through the forks and down to the axle. The axle tries to turn left, in effect “putting pressure” on the rotating mass that would cause that part of the wheel that is rearmost to move in an anti-clockwise direction as viewed from above. But precession won’t let it move there. The motion manifests itself 90° in the direction of rotation – at the top of the wheel. That is, instead of the back of the wheel moving right, the top of the wheel is moving right. Since this gyroscope is connected to the rest of the bike, the bike leans to the right with it.
The movements are very small and probably imperceptible to an outside viewer. Steering by actually turning the wheel in the direction you want to go is only done at very low speeds.
So I’ve never bothered to find out the “lock-to-lock” distance.
- Just remembering, not a whole lot, really: 60, maybe 70 degrees total for off-road bikes, and off-road bikes tend to have more range than street bikes do. - DougC
While countersteering is the way to go, it isn’t because of gyroscopic effects.
The idea of turning left to go right is no more complicated than getting the center of mass shifted in the direction you are going to turn before starting the turn.
You do the same thing while walking/running. When you want to make a sudden direction change, you will move your feet out from under yourself oposite of the direction you want to go.
In either situation, if you did not begin leaning in the direction you wanted to go before you headed that way, you would fall over the other direction.
Counter steering is just a very quick and direct way to get the lean initiated.
As to the OP, all I can say is that most bikes have more than enough, though couldn’t put a specific figure on it.
You should never get a bike to the lock while riding (even slowly). Turns are ended by increasing the amount of turn to stand the bike back up. (in effect counter steering again, but the other way.) If you are putting around in a turn that has the bars at the lock the only way to stop the turn would be to apply throttle.
Interesting. I’ve never ridden a motercycle but I’ve ridden a bicycle forever and I’ve never heard of this. Is it unique to motorbikes?
Not at all, in fact it can be more noticible on a bicycle. Try it! It’s more noticible on a BMX or stringray type than a road bike or mountain bike I think.
And it’s very noticable on a bicycle with little trail at high speeds. I countersteer on my roadbike all the time.
I am not a physicist, but I am a helicopter pilot so I know a little about rotating masses. I’m also a motorcyclist.
You say countersteering is a way to get the lean started. But how does it get the lean started? By transfering the pressure from the handlebars to the axle. The effect (to make it easy to visualize) is of moving the back of the rotating wheel to the right (in the case of a right turn). Imagine you lift the front wheel and set it to spinning. Then get a stick and push on the back of the tire to the right. The bike will tilt to the right even though you are “steering” the wheel left.
This is due to precession. The bike tilts to the right because your pressure on the tire manifests itself at the top instead of the back. (i.e., 90° in the direction of rotation).
Gyroscopes are stable. That’s why they’re so useful. Once you have “set” the lean, you no longer have to apply pressure to keep it there. Okay, maybe a little due to friction – but basically you’re stable in the turn.
Going back to “leaning before turning while you are walking”, I have to disagree with your analogy because on a motorcyle the lean is what
causes the turn. When you lean while walking in a circle you counteracting a force. (I don’t remember if it’s centrepital force or the imaginary centrigugal force.)
My 2001 Kawasaki has a turning range of about 85 degrees - estimated. The only time it ever really comes in to play is when I’m parking ass-end first in a narrow spot. Putting the bike away for the winter entails about a one hundred point turn to get it where it rests. Frustrating, but because of the forks on the outside of the frame, I don’t see how they could make them turn much more than that.
This is an extremely common misconception even of writers of magazine about motorcycles.
A razor skooter has negligible amounts of gyroscopic affects and counter steering works exactly the same as on a motorcycle.
Obviously there is some gyroscopic affects going on, but you would steer a motorcycle exactly them same if you came up with a massless wheel that had no gyroscopic effects.
The main effect of the gryoscope between the forks is that it will require increased pressure on the bars to get the turn initiated as speed increases.
Okay, then, how is the turn initiated? You said:
I do not begin a turn by leaning into it. I apply pressure to the handlebar in the direction I wish to turn. If I wanted to, I could lean slightly to the left before puching right, and I would turn right without falling over. Please explain the physics of countersteering.
Re: the Razor scooter. The Razor is much lighter than a motorcycle, so it doesn’t need a large gyroscope. The centre of gravity is also much higher than on a motorcycle, so it leans more readily.
The major effect of the gyroscope (front wheel) is to increase the amount of pressure on the bars required to counter steer.
That is the reason that going to lighter wheels and tires (of the same dimensions) make a bike feel quicker and lighter on steering.
I will illustrate a right hand turn by counter steer.
By training you put pressure on the right grip (push it forward). This points the front tire slightly to the left. You are now attempting a left turn and the bike immediately begins to fall towards its right side. When the bike is leaned over as far as desired, you take release the pressure on the right grip. Here is where the gyroscopic effects are actually interesting on a motorcycle. As a bike falls into a lean angle, the front wheel’s rotation axis is altered much more than by the counter steering effort. The reaction of the front tire to the changing (increasing) lean angle is to try to turn the front wheel and handle bars into the turn.
So I’m correct in saying that the turn is initiated by gyroscopic precession. You are correct in that the lean which is initiated by the precession causes the turn, and this is caused by the rake of the forks.
To get back to the OP, since the actual range of motion is not a critical factor in being able to turn, some bikes have a very limited steering lock.
There are two main ways to steer a bike, bar-steering and counter-steering, although there are other very advanced ways too, only for the highly skilled or( extremely desparate measures)
Generally, the sportier the bike is, the less the steering lock, and the more commuter biased it is, the greater the lock.
If you have a very limited steering lock then doing U-turns can mean a great deal of paddling around with the feet to-ing and fro-ing and making a 23point turn.
Step forward Italian bikes, which are notorious in this aspect.
Bikes like this are intended for use at high speeds, preferably on tracks where steering is accomplished by means of counter-steering, weight transfer or, if you are truly gifted, rear-wheel sliding.
Having a lots of steering movement available on such machines is irrelevant, and makes fairing design less efficient, aerodynamics are crucial to the handling of high speed machines.
Trailbikes usually have a good range of bar movement, and can turn on a dime, and those small wheels on scooter allow very tight turning circles.
Interestingly there is a crossover speed at which countersteering will not work, and instead you have to lean your bike one way, whilst you lean in exactly the opposite, this will allow even a sports bike the means to u-turn at low speed but it’s not an easy skill to master, and those plastic fairings are rather expensinve to repair or replace if if all goes pear-shaped.
Althought the crossover speed between counter-steering and handlebar steering should be differant for every bike, it always seems to be just around a low jogging pace, the crossover between the two methods of steering is due to there not being enough precessive force to counter-steer.
well, it looks like the q has been answered, so i’ll just add that my GB500 only has about 60 degrees max and it is a pain in the ass to roll around in the garage!
the RZ’s have about 90, except the right switch housing/throttle housing will hit the side of the tank if it is not rotated properly. This is why there are so many used RZ tanks with dents all in the exact same spot on the right side!
When you countersteer the bike rotates on the center of mass. If you want to go left you turn the bar to the right, the bottom of the bike goes right and the top goes left leaning the bike to the left. If you watch motorcycle races on TV you can watch this as they enter the turns. This movement is so slight and instictive that many riders do not even realize they are doing it but at higher speeds and more radical turns you do have to notice it. It is the same on a bicycle but the movement is even more subtle.
The only time lock to lock really comes into play is when you are pushing the bike along with your feet or in some cases slow parking lot manuvering…
I have quite a bit of experience on motorcycles, the first time I rode a wave runner (jet ski) I was confused when it kept going the oppisite of the direction I wanted to turn.
On my Yamaha Seca II the bar turns close to 45 deg in either direction so probably about 70-80 degrees total lock to lock.
Hey, I ride one of those. Got it new in 1994 and it only has a bit over 71,000 miles on it.
Good lord I can’t imagine having almost 90 degrees, I would guess my R1 has 45 or so at the most.