Back at the beginning of May, I had a weekend of frame repairs! SB4409 had new transfers and a bit of clear coat, while SB6560 had new gear lever bosses brazed into place. Before I tidied up and put the files away, I thought I’d squeeze in one more project; SB632. This is a special little frame that has had a modification at some point in its life to add a gear hanger and increase the thickness of the rear track ends to accommodate road wheels and gearing. This is the first step to restoring SB632 back to how it was originally.
There will be several sections in the restoration of this frame. The brake bridge needs to be dealt with together with the hole drilled in the fork crown. The crimped seat stay ends also need work. Once all the frame work is done, it will need some areas of paint and finally some new transfers… but first, those track ends…
As a reminder, here is what I found when I bought this frame…
I couldn’t tell if the hanger had been welded or brazed into place. Whichever way it was done, there didn’t seem to be much effort put into cleaning up the area before painting as there is lots of splatter and rough areas. The seat stay appears to have been hit with a cold chisel to create the indentation.

Four things had to happen to restore these ends.
- The hanger and the excess brass needed to come off
- The metal strips used to widen the ends had to be removed
- The holes that were originally drilled by the SBDU needed to be re-drilled
- The damage to the drive side seat stay which allowed clearance for a block and chain had to be repaired
Starting with the first item, removing the hanger. There is nothing needed other than a hacksaw and the ability to cut in a straight line. I just needed to make sure I didn’t cut too far into the end and just cut the hanger, while leaving enough metal so I could reform the edge with a file. This is how it looked after the hanger was removed and I did a very quick clean up with the files. It’s not pretty but it’s a start.

The track ends are very thin so I needed to be careful removing the extra metal that had been brazed to each side. I opted to use a hand file rather than anything electrical as the hand file is easier to control and less likely to grind into the already thin metal. As the extra metal came away, I started to see tell tale signs of the original SBDU drilling.

These ends needed a lot of filing, and the danger was that I might remove the clean crisp sharp edges, so it was all about taking it easy – it definately gave me plenty of practice with the files.

And that practice was paying dividends…

The first bit of work to clean up the drive side end was nearly done. All I had to do was follow the ‘template’ left by the brass and re-drill the holes – it didn’t take much to pop a drill bit through them and let daylight come through for the first time in many years!

I’ll leave that for now and come back to it when both ends are ready to be finished. So moving onto the non drive side. This end still had a lot of work to do but at least there is no gear hanger to deal with.

Again, the slow and steady work with the file was revealing the original SBDU drilling – it was even starting to reveal the original marks where the track nuts would have been fastened, leaving a permanent mark in the metal. The small circular brass ‘template’ markings identified where I needed to drill.

The only option to fix the drive side chain and seat stay damage was to fill them and re-shape the round tube profile. I wanted to avoid heat at all costs! This is how they were when I got the frame – I’m sure they had just been hit with a cold chisel to form that crease in the seat stay. The chain stay appears to have been ground down with a power file.

But after lots of work and sanding, the seat and chain stay ends now looked so much better…

There is still a bit of finishing work to do to the shape of the stay ends but I’ll incorporate all of that when the frame is ready for prepping and paint.
The drive side rear end of SB632 once looked very sad, a poorly brazed gear hanger, damage and splatter to the paint and some horrible steel brazed to the inner and outer surfaces to widen them. This work also covered up the original SBDU track end drilling…

After a lot of work, it is almost done and back to how it should be… the hanger is gone, the extra metal is gone, the damaged paint is gone and the holes are back!

The frame work on SB632 still isn’t complete. I need to decide what I am going to do with the rear brake bridge.

Do I leave it as it is or do I remove it and fit a plain round bridge suitable for a Track frame? I think I’ll have a ponder while I work on something else!


Leave a Reply