The garage at my house is practically a bike shop. For five roommates we have eight to nine bikes, a moped and a broken down motorcycle. Bikes hang from the ceiling on hooks and the shelves are filled with parts for broken bicycles. The only thing we need to complete our little “shop” is a unicycle and a tandem bike.
All the bicycles in our garage have the same diamond frame. There are different bike frames available but the diamond figuration seems to be standard. A number of different components make up a diamond frame. The head tube holds the handlebars and runs down to the fork at the front of the bike. The fork holds the wheels. The top tube is the horizontal bar that goes up toward the bike frame. Running diagonally on down the chain wheel is the down tube. Lastly, the seat tube runs from the seat down to around the chain wheel.
There are a number of different materials used for bike frames, all of which have their own advantages. Aluminum tube swaging is used to make frames out of aluminum alloys. These frames have a greater strength-to-weight ratio compared to the average steel alloy frame. Aluminum bikes are often lighter, but some riders claim steel frames provide a smother ride over aluminum.
All the bikes in our garage have steel frames with varying thicknesses. Compared to the mountain bikes, the road bikes not only have thinner wheels but thinner frames as well. Steel tubing is often less rigid and allows for some shock absorption. More expensive steel frames might even employ butted tubing. The thick tube ends and thin tube middles can reduce the weight of the frame. For hardcore riders titanium frames are available. These are expensive, high strength frames popular for performance racing bikes. There are many materials used to make bike frames but aluminum, steel and titanium make up the majority of the market.