Subject: Riding on Ice
From: Jobst Brandt
Ice riding is best done with studded tires of which there are a few
suppliers, mainly in northern Europe, such as Nokian.
[Nokian Tyres used to produce bicycle tires, but divested the brand to Suomi Tyres- a Finnish company that makes high quality bicycle tires for any kind of riding weather and trail conditions. -- Harriet Fell]
Riding on ice, especially frozen lakes, requires a few practical tricks. This applies to slick as well as studded tires. Ice, in contrast to fresh snow, is slick no matter whether it is frozen water or firmly compacted snow. It offers poor traction. Therefore, riding on ice should be done in top gear to avoid rear-wheel spin. This is similar to driving a car with a manual transmission, where starting in second gear helps avoid wheel spin. For bicycling on level ice, top gear is best for both starting and cruising, because while starting, acceleration is the main force, while once rolling, wind drag, even at low speeds, readily exceeds traction.
In skating over thin ice, our safety is in our speed.
-Ralph Waldo Emerson
In the absence of studded tires for frozen lakes without a snow crust, slick tires are better than ones with miniature automobile tread because they give more contact surface, thereby reducing contact pressure and slip.
Braking with the front wheel is impractical for two reasons. Skidding the front wheel usually causes a fall, and there is no way to detect that the front wheel is skidding except by falling. In contrast, rear wheel skidding is benign and can be easily detected. Continuing to pedal while braking enables a precise ABS. When the rear wheel skids, the pedals stop suddenly, to which one can respond almost instantly by letting up on the brake. The response speed and precision of this method are surprising.
Good gloves help not only against the cold, but with inevitable falling, they protect the hands from the ice. Frozen lakes are a wonderful way to appreciate landscapes where there is no alternate route and are safer than riding with traffic on icy streets. Thin ice, a term heard often with risky adventures, is a hazard that occurs from currents and from convection caused by gas bubbling to the surface in marshy areas. Stay away from reeds and swamps.
Water in a frozen lake is at 4°C (39°F), its greatest density, because colder water rises to the surface and begins to freeze, while warmer water rises to the surface and cools. Marsh gas bubbling to the surface brings 4°C water to the surface to melt ice, causing thin hollow domes that no longer contact the water.
Thin spots can be detected if the surface is clear ice, but they present a hazard just the same. The bubble method is used to protect boats too large to be lifted from the water. An underwater air-bubble pipe in the shape of the boat waterline, bubbling air through a series of small holes, produces a gap in the ice around the boat. This prevents the hull from being crushed by the ice on the lake.
The Big Freeze of 1963
An important consideration is that escaping from a hole in the ice, should a breakthrough occur, is practically impossible without external help.
More Articles by Jobst Brandt
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