Picture Page 2

Second Picture Page, Frames in Construction

Second assembly - on the table, and finished.

Prepare the rear triangles.

I have a whole page (see the sidebar menu) on a gizmo to help keep the rear triangle aligned properly while bending. Select the REAR TRIANGLE JIG

In which case, you can make it look like this with a little heat and bending.

Sometimes, the cut seat stays seat down tight onto the old seat clamp/lug of the finished 'second assembly'. Sometimes they don't. You want a snug fit here for the fillet braze that attaches the stay to the bike frame - this makes it strong.

You might find it is a bit loose, like this.

Again, if you need to. Check it first, you might not have to make these bends.

How do you make these bends?

Like this:

First, apply heat (red arrow) about 2" down on the outside of each seatstay. Use a bit of conduit slipped over the top of the stay and bend OUT (blue arrow) about 10 degrees. Freehand is fine.

Second, apply heat to the INSIDE of the seatstay, about an inch below your previous bend. Bend the stay back IN as shown (arrows shown for one side only in this picture).

NOW it is snug!

Alignment - Slowly, carefully. Take your time........

This is my table top for brazing the rear triangle. The frame is held upside down with a tabletop vice/clamp. I plumb it with that level. The rear triangle is placed on the table, spacers are below the triangle seat stays to center it on the top tube and level it. There is a scrap hub IN the dropouts. That's the set up.

Alignment can be achieved in several ways. Micrometers. Eh. String. You can run a string from the left rear dropout forward to the bottom bracket and then back to the right rear dropout. Then center the rear downtube in between. This is the 'old Italian' master's way of alignment, I have read. Or

you can eyeball it. This is like eyeing a bit of lumber, taking the foreshortened view down the length of the board. The picture here doesn't do what your eye does - your eye gives you a stereoscopic view over the bottom bracket and to that triangle at the rear. I make a judgement - does that rear downtube EXACTLY split the triangle into two equal triangles? Of course you have to walk back and nudge it. Adjust. Come 'out front' and look at it again. And so on. I make the walk several times on each frame, until I am happy with this foreshortened view. It's worth the time now.

Then BRAZE/WELD it - top and bottom! This alignment, and this braze joint, are the key to a successful frame!!