Countersteering, tailgating and roadrage.

Been riding a lot in the evening rush hour lately. I hate it. For a start it’s more of a mad 240 minute scramble. But when there are things to be done things get done. I’ve noticed a pattern of behaviour I don’t like . It starts with someone following too close. It’s always a Ford Focus, driven very aggressively and following very closely, particularly through sections where the traffic ahead of me is behaving unpredictably and eroding my braking distance. At some point I will need to turn off and will check behind me (as if i can see anything beyond ), indicate, change my position in the road, flash my brake light, then break and change gear ready to make the turn, perhaps being ready to stop or indeed stopping if it’s a right turn across oncoming traffic. Shoulder check in the direction of turn, and start turning, a nice tight precise turn to put me in the command position in the road I’m turning into, without cutting into lanes I shouldn’t be in. Then the tailgater passes me beating up their horn. I had assumed this was mere rage at being slowed down. Then I saw this:

Yes it’s yet more of a bike riding towards the camera along a white line. What I hadn’t noticed is how far the bike moves away from the direction of turn as countersteering takes place. And so I have a new theory: Expert tailgater has forced car into a space with no clearance and is then spooked as the bike appears to move back into the space that was vacated. I’m not sure whether to someone who doesn’t get bikes the act of turning looks like a rider might be changing their mind at the last minute, or whether there was a serious collision risk. So how to minimise the latter? I guess i could refuse to give up command of the road, that is staying in or near the centre of my lane, until I am committed to turn so that the tailgater cannot squeeze into a space that is too small. Or I push right into the gutter or onto the centre-line of the road and slow down more to allow more room. It’s not an issue that’s in any of my books. I’m for the former, choosing not to allow following vehicles past.

Steering is countersteering.

Motorcycle racing games amuse me, there is all this detailed simulation of moving weight around forwards and backwards to manage grip during acceleration and braking, yet the most basic part is utterly wrong move control stick left, bike goes left. This further propagates the misconceptions of how two wheeled vehicles steer.

On a motorcycle (or bicycle) apply a small force to the handlebars turning the front wheel to the right (usually by pushing on the left bar) and the bike will lean over to the left. Stop applying that force and the caster effect will cause the front wheel to turn itself to follow a stable curved trajectory.

At very low speeds, frictional forces between the tyre and road may prevent the castor effect so the rider must both initiate a small amount of lean and then turn the bars to follow the curve himself. It may be the case that a slow turn can be initiated by muscling the bars around and moving the body to balance, this will likely cause a wobble that will need steering input to correct, resulting in a similar counter steering manoeuvre.

Beyond walking pace steering is a brief light push on a bar to initiate lean, then applying no force to either bar as the wheel aligns to the lean angle by the caster effect. Small pushes on either bar adjust the angle of turn. Briefly push the bars so the wheel points further into the curve and the bike will stand up. Of course it’s all about knowing how hard and how long to push for, which is something one picks up with practice very quickly.

My point is the control input the rider makes is a torque (turning force) on the bars, not a degree of rotation as it would be on a four wheeled vehicle.

Furthermore one cannot steer a bike by leaning alone. This myth propagates as changes in body position executed badly cause a torque on the bars and thus turning. The Califonia Superbike school has a bike with one set of bars fixed to the frame of the bike and another fixed to the front forks, turning the front wheel in the conventional manner. It is a tool used to demonstrate to riders that lean alone will not steer a bike as a moving bike is incredibly stable.