chromium-molybdenum steel , auch: chromoly steel , auch: cromoly

The air chamber is a cylinder of thin shell made by alloy of nickel chromium-molybdenum steel.

When introduced, most BMX bicycles were made from either hi-tensile steel or more expensive but stronger chromium-molybdenum steel.

The second type air gas (oxygen) was stored at 225 atm in a 980-liter main chamber made by machining a block of nickel chromium-molybdenum steel, an alloy first developed for battleship armour.

The basis for this bike was Egli's central tube frame constructed from nickel-plated chromium-molybdenum steel and the engine was completely redesigned with a longer stroke crankshaft (105 mm), special main bearings, dry clutch, timing belt primary drive.

Chromium-molybdenum steel, commonly known as "Chromoly", while more expensive than high-tensile steel, it was cheaper than aluminum, in part it was much easier to fabricate and more reliable in terms of durability than most other aluminum framed race bicycles on the market at the time.