I don't understand the question?

 

Several of the Triumphs Mule builds remove the subframe tubes and use the engine as a stressed member - aka the engine serves as part of the frame. Think Ducatis and others.

http://mulemotorcycles.net/triumphs.html

 

Thank you for the clarification. Now the question becomes, is the Triumph case able to withstand the pressure points? The Ducati’s are designed that way. I dunno, sometimes it seems the custom approach goes too far? NTM, the bike looks odd/incompletish.

 

Personally,I think going “tubeless”makes the bike look,somehow,incomplete. The tubes add very little weight and provide some protection for the cases,oil pickup and wiring. Everybody knows my vision for the front of that engine.lol

 

I'm not an engineer, but it seems logical to me that motorcycles that use the engine as a stressed member have had the frames and engines, particularly their mounting points, designed to accommodate those stresses. It's just my opinion, but to me it makes sense. Addressing the Bonneville specifically and it's retro appearance, I like the look of the frame with the tubes in place.

Bob

 

I'm not an engineer, but it seems logical to me that motorcycles that use the engine as a stressed member have had the frames and engines, particularly their mounting points, designed to accommodate those stresses. It's just my opinion, but to me it makes sense. Addressing the Bonneville specifically and it's retro appearance, I like the look of the frame with the tubes in place.

Bob

My thoughts exactly. The engineers designed the frame that way for a purpose.

 

From an artistic perspective, I like what they have done/are able to do to those bikes. I am not qualified to say anything about the safety factor/engineering perspective of their decision. Looks neat, might not be as safe - but I don't know.

 

The subframe is foe cosmetics only it is unnecessary.

 

Unless you screw the head stem to the cam cover.

 

The Thunderbird 1600 line has engine as stressed member as do Tigers, at least my last 2 Tigers (955i & 1050) I presume the newer 800/1200's do too.

 

My member is stressed thinking about it.

 

Hinckley Triumphs were all engine as stressed member until the classics came along. In fact, according to a guide on the factory tour some time in the mid 90s, Triumph thought of basically using the engine as the frame and bolting front and rear subframes on to hang the wheels off (as per Egli Vincent) but decided that the public probably weren't ready for something as radical as that.

 

I don't know about the frame tubes but leaving the front fender off isn't such a good idea if you're actually planning on riding the bike.