Cannondale metal bikes are most likely aluminium frames.
Most modern bicycle frames are made of one of three components: Aluminum, Steel or Carbon Fiber. Aluminum can make for a more forgiving frame. Steel frames are hardy, transfer power well and are commonly found on BMX bikes and some mountain bikes. Carbon Fiber frames are the lightest and most expensive frames and are only found on the high end road bikes.
metal.
They are made of metal.
Window frames are usually made of aluminum.
Honda
It seems that the frames are made in Taiwan, then sent to Colorado, where they are inspected, and the rest of the parts are fitted.
Basically the same as road bikes, but with thicker tubes and bigger welds.
Most mountain bikes are made from Aluminum, some are made from carbon fiber and older bikes are made from steel. Quality, weight and strength vary hugely by manufacturer with most high end bikes claiming unique methods which either reduce weight, improve strength or both.
metal and rubber
There are several materials that can be used for light frames, all depending on where you draw the line for light. Today the materials most often associated with light frames is either carbon fibre or titanium.
Over the years a wide variety of materials have been used in bicycle designs. The earliest bicycle-looking designs used wooden frames. Overall most common material are various steel Alloys, with aluminium as a second. Then there are titanium frames, carbon fiber frames, a few thermoplastic frames, fibreglass frames. Even some listed as Magnesium (alloy) frames.