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Basically I decided the EX650 frame just has too much steel... Started with the hack-saw & welder, 32lbs off so far, still playing with the design of it but the next project is a new frame from the ground up in either Titanium or Chromoly. This OEM frame (silver) is 45lbs (62lbs with the swingarm)! I want to keep it under 10lbs (15 with the swingarm). Also the currently missing sub-frame on the orange frame is going to be made with a few titanium tubes to support the rider (weight will be less than 1lb).

I wanted to post this to ask A) if there is anyone else playing with the frame/weight and B) to get some general feedback - I have found that hearing other people's thoughts is very helpful when designing/building/modding. And if you want to tell me I'm an idiot and wasting my time and here's a list of other mods etc. don't waste your time because you're right (and I agree). I just like having a truly unique machine, and I don't think a bike can be truly unique with just off-the-shelf parts so I will try stuff like this instead...

P.S. please forgive my spelling :p
 

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Interesting project, but I'm just wondering if the cost of the materials and your labour is actually going be that effective?
I'm assuming you have experience in this field(welding in particular)? Main reason I ask is, and I am by no means educated in this field at all, the amount of weight and frame work you have taken out/modified, will the bike still have enough support to be able to bear a riders weight, and the torque of the engine etc?
Like I said, I have no experience in this field, but I do know, if you take away too much, it will just fold in on itself.
Good luck with it, I certainly want to see how this turns out!
 

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Cool project, no matter what....Plus, anyone who can bend metal like that gets a pass on spelling.
 

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Discussion Starter #6
Interesting project, but I'm just wondering if the cost of the materials and your labour is actually going be that effective?
I'm assuming you have experience in this field(welding in particular)? Main reason I ask is, and I am by no means educated in this field at all, the amount of weight and frame work you have taken out/modified, will the bike still have enough support to be able to bear a riders weight, and the torque of the engine etc?
Like I said, I have no experience in this field, but I do know, if you take away too much, it will just fold in on itself.
Good luck with it, I certainly want to see how this turns out!
Zandit - you point out an important question/hesitation a lot of people have with something like this. The truth is the frame supports the motor as much as the motor supports the frame (by design from the factory). On any frame there are really just 2 stress points to watch for: the neck where the tripple tree is mounted and the swingarm pivot. As long as those two points can't bend/twist (relative to eachother) you can use the engine as a stress-member to help hold the frame in shape. I'm trying to think of a good analogy involving house-hold items but coming up blank at the moment. In the grand scheme of things, for my purposes (drag racing), the frame can be quite minimal and this one will still have more frame than the minimal needed amount. That said, it's a frame modification and will be tested & monatered carefully to insure it will hold up before gettiong the "OK" - always always always safety first!! ...Unless it conflicts with budget or time :p Seriously though I am a skilled welder and good at the math/physics that goes into design - at the end of the day I have to trust my work with my life as I will be the one piloting it at hard and as fast at it can possably go and breaking a frame at 100+mph doesn't seem like it would end well. I appreciate your insight and concern though! Always good to have someone asking these things, so thank you! No more progress yet but will hopefully have something up soon.

P.S. Again, please forgive my spelling :p
 

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Cool project, no matter what....Plus, anyone who can bend metal like that gets a pass on spelling.
Man this made me laugh and laugh! I am going to quote you anytime someone talks smack about my spelling from now on!
 

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I'm glad you mentioned its a drag specific bike and not a stretched custom for the street or road track. The forces you encounter are very different. For example, a motogp bike is obviously very light (340 lbs) but the chassis actually needs to flex a lot. When cornering at super high speeds the suspension no longer work on bumps (for obvious reasons) so the chassis must be able to absorb that. Otherwise, Rossi and the like will get launched on the first bump they hit while cornering. Drag racing is very different. The suspension can work on bumps and the chassis requires much less input. You don't get the rear end twisting effect you do with a drag car. All that allows you to use unique materials like chromoly and Ti which are very light but also have very high tensile and sheer strength.

Well engineered. Good luck with it.
 

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If you dont mind, how do you select the "right " material for something like this?

Its one of those projects a thousand would love to do, but only one goes ahead with it. With your talent, its time to get an old r6 with a blow engine, and find an crashed fz09.....and see what happens when the two are near each other...

The utmost respect towards, you, sir! I wish you were my next door neighbor instead of the douchebag I have...
 

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If you dont mind, how do you select the "right " material for something like this?
That's sort of depends on who you ask. If you actually designing it using a software like CAD you would essentially model what and where your stresses are. That would tell you what your minimum material strength is. The engineer and project funder (the money man) can make the trade off of strength vs weight vs price. Obviously you have to meet the minimum strength but the weight you choose will drastically change the price of that raw material. Then there is also the consideration of what materials do you have the ability to work with. Some materials have very unique characteristics like welding flux or gas requirements so that often drives cost and decision.

That's usually the professional engineering approach. I suspect the OP has experience with these materials and is comfortable fabricating them and knows they are plenty strong and light for his purpose. So he went with what he knows (always a wise choice when your butt is on the line).
 
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