Derny race facts for kids

A derny race is a special kind of bike race where cyclists get a speed boost from a motorized bike called a Derny. Imagine riding your bike really fast, but with a powerful little motorcycle just in front of you, cutting through the wind!

A Derny is a unique motorized bicycle. It's built specifically to help cyclists go super fast in certain events. These events include motor-paced races, often seen in exciting six-day events or Keirin races. Sometimes, they are also used in motor-paced road races.

What is a Derny?

A Derny is a small, powerful motorcycle designed for a very specific job: pacing cyclists. It's not like a regular motorbike. Its main purpose is to create a slipstream, which is an area of reduced wind resistance, for the cyclist riding right behind it.

How Derny Pacing Works

The rider of the Derny sits very upright. This might look a bit strange, but it's done on purpose! By sitting tall, the Derny rider creates a larger area for the wind to hit. This helps the cyclist behind them by making a bigger "hole" in the air. This way, the cyclist uses less energy to go faster. It's like drafting behind a big truck, but much more controlled and precise.

The cyclist rides extremely close to the Derny's back wheel, sometimes just inches away! This close distance is key to getting the most benefit from the slipstream.

History of the Derny

The very first Derny bikes were made in Paris, France. A company called "Roger Derny et Fils" built them in 1938. These original Dernys were so good at their job that the name "Derny" became famous.

Even though the original company is no longer making bikes, any motorized bicycle used for pacing cyclists is now often called a "Derny." It's like how people might call any tissue a "Kleenex," even if it's not that brand!

Why are Dernys used?

Dernys help cyclists achieve incredible speeds that they might not reach on their own. This makes races more exciting and allows athletes to push their limits. They are especially important in track cycling events where high speeds are crucial.

You might wonder why other motorbikes aren't used. In the past, photographers' motorbikes sometimes rode in front of cyclists in regular races. This helped the cyclists, but it wasn't fair to everyone. Because of this, these motorbikes were banned from riding in front of cyclists in ordinary races. The Derny, however, is specifically designed and allowed for its pacing role in certain events.

Images for kids

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  Derny publicity material

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  Derny Taon 125, 1955/1956

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  This 650cc Triumph TR65 Thunderbird "Stayer" bike was first used at Leicester Velodrome in 1982. It's now at Herne Hill Velodrome. Notice the roller at the back and the upright riding position. These features help tell a "Stayer" bike apart from a true Derny.