Moto-Myths 2: How to Steer a Bike
Nov 20th, 2007 by Leo
Conventional (non-biker) wisdom says if you turn the wheels left you will turn left, if you turn the wheels right, you will turn right. With motorcycles, however, you turn left to go right: this is called counter-steering.
Physics 101
The theory of this is actually pretty simple: 2-wheeled vehicles turn by leaning in the direction of the turn. Lean a bike left, it turns left; lean right, turn right. The problem is a motorcycle has too much mass to be easily leaned over once it’s moving. This is where counter-steering comes in…
Q: If you were riding a bicycle and some bully were to run along side and turn your handlebars violently to the left which way would you fall?
If you said “to the right”, then you’re correct. A sharp left would drive the wheels to the left forcing you and the upper part of the bicycle to fall to the right. This is the key to how you steer a motorcycle. By turning the bars to the left the front wheel pulls to the left leaning the motorcycle to the right, allowing you to turn right. Because 2-wheeled vehicles turn by leaning in the direction of the turn.
How come some experienced motorcyclists disagree?!?!
This is what I find so interesting! There’s a lot to be said for instinct. People can counter-steer (to an extent) instinctively without realizing what they are doing. Bicyclists often counter-steer without realizing it, and so do some motorcyclists (usually Harley-type riders). What they will tell you is that they simply “lean in the direction of the turn to get the bike to turn…”
But what they are really doing is…in the act of trying to lean, they are gripping the handlebars and counter-steering. I can prove it. Sit on your bike and hold the bars with your elbows somewhat stiff (the way you would if you were trying to move something heavy) and lean your body to the left. Which way are you turning the front wheel when you do this? By moving your body to the left you are actually steering the front wheel to the right. Counter-steering!
Not only that, Keith Code’s “no BS (body steering) Bike” shows that it’s impossible to effectively steer a motorcycle at speed simply by leaning. All those “lean-ers” are really just counter-steerin, but they don’t know it. Monkey bars and similar Harley-type contraptions additionally force you to lock your elbows as you “lean” causing you to counters-steer more easily.
More theory…
So does this mean that when a motorcycle is in a turn, the front wheel is faced in the wrong direction? No. The wheel is faced more or less in the direction of the turn, but in the act of leaning (or leaning further) it faces further out of the turn… So if you’re making a constant left turn (in a circle) the bars would point left. But in order to get the bike to make an even tighter turn to the left you would “push” on the left grip causing the bike to lean left even further. During that whole time the front wheel would face left, but at the moment you make the steering input it would face slightly less to the left.
So do you have to continually counter-steer in a turn, or is it just to initiate a turn?
It depends on how far you are leaned over… If you are going for a full lean, Moto GP style, or a very slow turn at a moderate speed, the answer is: you only need to counter-steer to start the turn – once you’re in the turn the wheels follow the arc of the turn.
But there are speeds and lean angles at which you may have to keep applying the steering input for as long as you are turning at that speed and angle. So often times in spirited parkway riding you need to counter-steer, hard, and keep pressing in order to maintain the arc, otherwise the bike seems to want-to straighten out.
…If all that confuses you – then forget it, the theory is not all that important as long as you get the feel for it.
How the Pros Do It…
This is how expert bicyclists, scooter riders, and motorcyclists turn their bikes. Scooters and bicycles can-be turned by forceful leaning (usually), but when you watch skilled riders, they don’t whip their bodies around – they steer. How do you steer your bike?
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PS – So for those to whom counter-steering is a new idea, here’s a little exercise you can do on an empty street. At a moderate speed (30mph or so) make S-lines across the center of your lane. (Make sure there are no cars behind you…) Lean forward so that you can reach the handle bars while keeping your elbows bent. Push on the right grip to lean right, left grip to lean left. Try not to move your torso relative to your bike, but use only your arms. Gradually make sharper “esses” as you get the feel for how the steering works.
Related posts:
This is a very good description of the steering.