CUTTING BACKBONES

LongHornCycles

New Member
New to the website and these forums, have a question that i just want some general feedback on. i have a 1973 triumph that is currently stripped going for a full chopper and i bought a new lowbrow customs "P Nut" gas tank. as you know a '73 is an OIF model so the backbone where the tank sits is massive. so i cut and shaved down both sides so that this gas tank would fit smooth on the frame. im going to have the holes i cut welded flat this weekend. NOW ON TO THE WHOLE REASON FOR THIS POST....HOW unsafe is this? im not one to ride a bike with a reflective yellow vest, and im not fond of front brakes, but is my frame just going to snap if i hit a pothole going 60?
 
With proper bracing and welded in reinforcement... It SHOULD be OK. That being said, (hindsight) why didn't you split the tank, add a center strip and weld it back together to fit over the backbone instead? I'm assuming at the time it wasn't an option or maybe it was thought to be easier to cut the frame? Pictures would help though, there's several people on here who are geniuses when it comes to structural integrity.
 
http://i150.photobucket.com/albums/s104/cmorey/IMG_1304.jpg its not pretty yet but think of it like a lap band. i am going to have straight pieces of steel welded in almost the entire area to strengthen it and then body fill the rest to clean it up.
 
If you put [ IMG ]http://i150.photobucket.com/albums/s104/cmorey/IMG_1304.jpg[ /IMG ] without the extra spaces I put in there, it will embed your pic in the post like this:

IMG_1304.jpg
 
That should be ok IMO, Just make sure you box it in with some 1/8" metal.

Also be sure that when you are weldng that it doesn't pull and the frame stays straight, otherwise you'll be riding a banana. Missaligned frames are the #1 cause of speed wobbles because the wheels dont follow one another perfectly. You may need to put it in a jig or something that will hold it rigid while you weld it.
 
Rattlecan, thats exactly what i was thinking and thank you i just wanted to make sure that this wasnt some crazy idea in my head that i couldnt pull off. the frame is getting hardtailed too so im going to have this backbone welded tomorrow, then spend the rest of the next few weeks making the bodywork all pretty and flush. so when i do get my hardtail kit (weld on david bird) i will make sure that the frame is aligned and straight. should i start a different thread for the build updates or should i just continue on here? any other inputs are greatly appreciated!
 
If you go back and edit the first post of this thread, you can change the title to that of your build. That's the one everyone will see.

Good luck with the build man!
 
Yup - just rename your first post and the whole thread will get a new name.
 
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