[CBPayne]

This weekend or next I'm going to cut the top tail piece off my bike and weld some 1" 1/8 wall Dom tubing. About an 2" above the top shock mounts is where I'm cutting. I want to run the Dom tubing into the backbone of the bike. I'm using a 3/32 2% lanthinate and 1/8 309 filler. One problem is the shock mount is welded in a hollow chamber that is welded to the frame. How would you tie in the other ends into the backbone? Here's a quick doodle. Red lines are cuts to be made, the middle bar is being replaced with a straight piece.

[weldin mike 27]

What's the reason behind the adaption? Remember that things like that are designed to work they way they are and chopping and changing could cause more problems than its worth.

[CBPayne]

Because I'm building a custom bike. All this is doing is raising the seat hight. I'm not moving the shock mounts.

[Braehill]

CB,
Any reason that the existing seat area "has" to be removed ? If you're going to bob the bike, see if you can tie the shock mounts to the 1 1/8 dom and the existings frame tubes used for the seat mount. Maybe miter the dom so that it goes past the shock then returns forming point (maybe 120*) then you can put a gusset in there to tie it all together.

It hard to type out what I'm thinking. I don't know if that makes any sense to anybody but me.

Len

[CBPayne]

I'm sorry I typed that wrong. The Dom is 1" and the wall thickness is 1/8". I don't follow the miter the Dom to go past the shock mount. This is the frame that I want to build. I'm really just wanting to know the best way to tie in the Dom into the backbone. I still welcome any other info, advice, opinions. Thank yall for chiming in.

[weldin mike 27]

The best way to tie tubing in on odd joins is to lay the pieces on where they will go and work out cuts by eye. Then rough them with a band saw or grinder, take little trims until it goes where you want. Then weld it in. You probably won't be able to just cut a piece and have it drop in, it's trial and error.

[Braehill]

CB,
They did what I was thinking with the mandrel bend under the seat. I would tie it in just as they did, leaving the existing tubing where the old seat mounted. I think they may have replaced it with straight tubing and it might look better that way. That's where the strength is coming from, if it's removed all together you'll lose integrity.

Len

[CBPayne]

The bar in the middle that was the brace for the original saddle seat was replace with the straight piece for aesthetics as well more importantly to brace the frame.

[CBPayne]

I think I'm not going miter the ends of the tubing to fit the surface of the back bone. I'm going to notch them to fit on another piece that runs the width of the back bone.