What is a "diamond" frame?

[IT WASN'T ME!]

I understand the basic frame types: twin spar, bridge, backbone, full cradle, perimeter and so on, but I don't understand what a Diamond frame is on a motorcycle. I know that a standard bicycle frame is called a diamond frame and early motorcycle frames that were of that same bicycle design were called diamond frames, but I see many modern bikes with what the magazines call diamond frames. However they never show a pic of the frame. Some, from what I can see with the bodywork on look like full cradle frames and others look like they might be some sort of tubular backbone type frame. Just curious.

 

[HeatXfer]

I'll just leave this here...

 

[louemc]

^^^ Ummm Diamond frame, wasn't mentioned in that Wiki link, Was it?

Pretty much everything else, was.

 

[HeatXfer]

^^^ Ummm Diamond frame, wasn't mentioned in that Wiki link, Was it?

Pretty much everything else, was.

From the Wiki:

"Stressed member engines were pioneered at least as early as the 1916 Harley-Davidson 8-valve racer, and incorporated in the production Harley-Davidson Model W by 1919.[6] This was called a keystone, or diamond, frame.[7][8] The 1946 Vincent Series B Rapide was designed with an advanced chassis, termed a "tour de force for its day,"[9] that included a stressed member engine. During early testing of the 1983 Kawasaki GPZ900R, twin downtubes were included, creating a full cradle, but the downtubes were found to carry little load, so they were removed, relying entirely on the combination of the steel backbone and engine for chassis rigidity.[10] BMW's R1100 series twins of 1994 relieved the frame of stress entirely, with the engine carrying the total load from the front Telelever fork to the rear Monolever.[11][12]"


More here: Honda CBR250R frame

 

[IT WASN'T ME!]

From the Wiki:

"Stressed member engines were pioneered at least as early as the 1916 Harley-Davidson 8-valve racer, and incorporated in the production Harley-Davidson Model W by 1919.[6] This was called a keystone, or diamond, frame.[7][8] The 1946 Vincent Series B Rapide was designed with an advanced chassis, termed a "tour de force for its day,"[9] that included a stressed member engine. During early testing of the 1983 Kawasaki GPZ900R, twin downtubes were included, creating a full cradle, but the downtubes were found to carry little load, so they were removed, relying entirely on the combination of the steel backbone and engine for chassis rigidity.[10] BMW's R1100 series twins of 1994 relieved the frame of stress entirely, with the engine carrying the total load from the front Telelever fork to the rear Monolever.[11][12]"


More here: Honda CBR250R frame

The wiki link wasn't very helpful, but the Honda 250 link was, thanks.

 

[ScottRNelson]

The wiki link wasn't very helpful, but the Honda 250 link was, thanks.

So here's the answer:

This is new to me too.