What does the curve ahead sign mean?

This sign is posted before a bend on a country road. When should you do most of your slowing?

Before you enter the bend, so your speed is steady all the way through

Braking hard while the wheels are turned uses up grip that you need for steering, and that is how a car runs wide. Set the speed on the straight, hold it through the bend, and accelerate gently once the wheel is coming back.

This sign appears at the roadside ahead of you. When should you slow down?

Before you enter the bend, while the wheels are still straight

Braking inside a bend throws weight forward and uses up grip that the front tires need for steering, which is how vehicles run wide. Set your speed while you are still travelling straight, then hold a light steady throttle the whole way round.

This sign is at the roadside and the bend it warns about starts just past it. Where should your braking happen?

Before you reach the bend, so the car is settled through it

Braking and steering share the grip the tires have, and asking for both at once is what puts a car off a bend. Get the speed off while the wheels are still straight, then hold a steady throttle around the curve. The sign is placed to give you the distance to do exactly that.

This sign is at the roadside on a country highway, and the road beyond it disappears from view. Where should the slowing down happen?

Before you enter the curve, so you are already at a settled speed

Braking in a curve shifts weight onto the front wheels and takes grip away from the ones doing the steering, which is how a car ends up over the centre line. Set your speed on the straight, hold it steady through the bend, then accelerate gently as the road opens out. The sign is placed far enough back to give you room to do that.

This sign appears on a country road you have never ridden. Where should the braking and the gear change happen?

Before you reach it, so the bike is at a settled speed by the time you turn in

Grip is shared between turning and braking. A bike that is already leaning has spent part of its grip on the corner, so a handful of brake there is what runs a rider out of road. Setting your speed on the straight leaves the whole of the corner for cornering.

This sign appears on an unfamiliar road. You cannot see where the bend goes or how tight it becomes.

Finish the slowing before you turn in, then hold or gently open the throttle through the bend

Grip is a single budget shared between turning and slowing, so a bike that is leaned over has very little left for the brakes. Getting the speed settled while you are upright means the whole of that budget is available for the lean. A steady or slightly opening throttle also keeps the suspension settled instead of pitching the bike about mid bend.