| If you are going to build a motorcycle, the | | | | distinctive look, but other designs are |
| frame determines the basic look of the bike. | | | | better in terms of strength and rigidity. |
| Of course motorcycle frames affect not only | | | | |
| the appearance of the bike but the handling | | | | Perimeter: These frames originated on racing |
| and safety of the finished machine. | | | | motorcycles. The steering head and swingarm |
| | | | are joined at a very short distance, reducing |
| Frames are the basic skeleton to which other | | | | flexure and torsion substantially. They were |
| components are attached. They hold the | | | | originally made from steel but most are made |
| motorcycle tanks and engine and provide | | | | from aluminum nowadays to save weight. Once |
| support to the whole bike. Most frames are | | | | the advantages of this frame were seen, they |
| made of steel or aluminum but there are also | | | | were adopted by most motorcycle |
| other choices such as carbon-fibre. | | | | manufacturers. |
| | | | |
| Motorcycle frames generally fall into one of | | | | Monocoque: Another specialty frame that is |
| several categories. | | | | even rarer than the backbone. They are very |
| | | | heavy and rigid, combining seat mounting, |
| Single Cradle: This is the simplest of the | | | | tank, and tail into a single sturdy piece of |
| motorcycle frames, a design that harks back | | | | metal. They are used almost exclusively on |
| to some of the earliest motorcycles ever | | | | specialized competition bikes and are not a |
| made. It has a single large tube for a spine | | | | good choice for street bikes. |
| and smaller tubes that cradle the engine. | | | | |
| This is commonly used on off-road bikes. A | | | | Trellis: European manufacturers came up with |
| variation is the split single cradle which is | | | | this design although it is catching on in the |
| a single cradle that splits into two cradles | | | | US as well. It uses many of the same |
| at the back for the exhaust. | | | | construction principles as the perimeter |
| | | | frame and matches it in rigidity and weight. |
| Double Cradle: An evolution of the single | | | | Its distinctive look is formed by a "trellis" |
| cradle, it uses two cradles on either side to | | | | of short tubes that make up the body of the |
| hold the engine. These were commonly used on | | | | frame. It requires more effort to |
| simple road bikes and some custom bikes, but | | | | manufacture than the perimeter but the result |
| have mostly been supplanted by perimeter | | | | is extremely strong. |
| frames. | | | | |
| | | | One of the earliest decisions to make is |
| Backbone: These are specialty frames that are | | | | which of these motorcycle frames is right for |
| used rarely. It has a solid metal backbone | | | | your bike. Many of your other decisions will |
| and the engine hangs suspended from this. | | | | depend on the type of frame you choose so |
| It's a simple and inexpensive frame with a | | | | consider the options and choose wisely. |