Thursday, January 8, 2009

Holy Shizznet, somebody stop this guy!

Oh man, there's no turning back now! Today we cut the complete backbone and neck off the frame, and took part of the downtube off as well. As you remember from before, there was no saving any of this. Now you can see how important it was to repair the seatpost before we went any further. Before I cut the frame, I bolted in a cradle I made a long time ago to keep this area square during extensive repair work like this. If you remember from before, there was a Big Twin engine in here at one time - most likely a Knuck or a Flattie, and 3 of the 4 engine bolt holes actually lined up with my cradle, so that makes me happy!

You can see the remnants from the weld I talked about cutting out previously. Actually, the webing area isn't that bad, but we need a structurally sound area here when we're finished. We also need a way to attach the new backbone to the web area itself. The old socket won't work for that. Why? Because the way a VL backbone is made, you have the outer tubing, then you have an inner split sleeve, and it's sandwiched together with furnace braze. We can't weld over braze, remember? Braze + weld = CRACK! If we ground out the inner liner and the braze, the socket would be way too thin to use, so........

The socket gets completely cut off, and we lay a piece of 5" long tubing (half the length into the webbing, half extends past the webbing) into the webbing to take it's place. Then, a 1 1/4" OD x 1/4" thick ring for the outer sleeve to fit over snugly and fill the back of the outer sleeve, and then the tubing slug is welded in place. The new 1 1/4" OD x 1/8" DOM backbone will slide over the 1" tubing slug, and butt up flush to the ring.

With a scrap piece of the same tubing I'll be using for the backbone slid into place, and the sleeve over the top, you can see where we're heading. It's starting to appear "stock" again in this area, which is the whole idea of going thru all this - looks nice! Next step will to fab up the backbone, and get the new neck into place.


Chico said...

i'm diggin this.

thanks for the info and pics.

Chris K said...

Junk to gem. It's great to see someone save old stuff and do it right. It's the castings and fittings that make old frames so cool.