Monocoque : Very popular with the good old Vespa scooters, the Honda super-cub 50/100 and more. This frame is made out of pressed metal sheets, steel or aluminum. One modern bike which utilizes this frame is the Kawasaki 1400 GTR.
Single Cradle : Maybe the most popular, especially among bike builders, show bikes and custom bikes. Mostly built from steel tubes. Although it can not handle hyper sport riding, it is simple and strong and for builders, gives plenty of room and a good base for any custom built bike. Models that use the single cradle are the old Triumphs and other British bikes, and today’s most dual-purpose, touring and custom motorcycles like the Suzuki C50 and more.
Double Cradle: Such a frame was popular during the 80’s with the GSX-R line and other Japanese bikes. This frame was a giant leap forward in chassis rigidness and handling. Build from aluminum and aluminum alloys it made the sport bikes lighter and more agile.
Perimeter Frame: The next step after the double cradle, is the perimeter with two massive beams surrounding the engine. Almost all today’s hyper sports, including GSX-Rs and etc Japanese use this frame. Made from aluminum and alloys. Buell motorcycles took this a step further with a fuel-in-the-frame design.
Trellis Frame: Most identified with Ducati, the trellis frame is very rigid and compact. It is based on steel tubes connected by triangular shapes. Ducati builds its frames from tubular steel hollow tubes, while Suzuki and others prefer aluminum alloy oval tubes. Triangle is the most rigid shape (see cranes for ex.) so if built right, these frames can supply rigidness, with low weight.
Omega Frame (C-shaped):
Used by only a few rare models, this C-shaped or Omega frame was developed in order to being able to locate the front fork horizontally, and by that to separate the braking forces from effecting the steering. Italian Bimota was the first to implement this on the Tezi . Yamaha followed up with the GTS 1000 that was the first mass production bike to incorporate this design.
Frameless Chassis: I bet you didn’t see that coming ha? that can be an option as well.
In the early 90’s John Britten designed the revolutionary Britten V1000 that had its engine function as the chassis, with the swing arm , front suspension and practically all the rest, connected to it. Besides being a beautiful peace of art, the bike went on to win the Battle of the Twins in Daytona, USA and set a number of world speed records.