Bikes are not much good if you can’t attach cables for brakes and gears, it would also be nice to carry a water bottle or two. That means that day 4 was all about ‘braze-ons’ – those little guides that you pass cables through!
But just to be clear, the name is a little mis-leading as we would be using Silver Solder to attach these and not brazing them with brass; so should they be called ‘Silver Solder-ons”? Probably not, I think I stick with braze-on!
Back in the day, holding things to the frame was achieved with clips. And you would get some beautifully crafted clips but at the end of the 70s/start of the 80s, things started to change. Braze-ons started to appear. I went with a good selection.
2 x sets of bottle bosses, 2 x gear lever bosses (just in case I want to go retro with gear levers at some point), 3 x cable guides for the brakes and gears, 2 x pannier rack bosses for the rear stays and a fitting for the front mech. I could have just used a band on front mech but a little future proofing is a good thing! The brake bridge was included but the chain stay bridge, Dave explained, would be made later.
As with everything, there is an easy way to fit bottle bosses using a jig to drill holes in the seat and down tubes. This was the first time I’d done Silver Soldering; less heat, a softer flame and lower melting point rods and within a few minutes, bottle bosses were fitted.
Gear lever bosses are now actually starting to fade away in favour of cable guides and adjusters as most bikes will now control gears via handlebar mounted STI levers. However, I’m a retro kind of guy so want to keep with bosses for now and simply fit guides to the bosses. Dave’s jig for fitting these looked like something from a torture chamber but as with all his methods, it does exactly what it was made for.
Next up was a front mech fitting. You are limited in the size of chain rings with these fittings as they have a definite upper and lower height limit, however, if you know what you are going to be riding in terms of gearing, Dave has the perfect height measurement buried in his brain that will work. No fancy jigs for this – you can get fancy jigs but all we used was a clamp!
Last up for braze-ons were the cable guides, 2 just on the lower left hand side of the top tube and one under the chain stay. Holding the frame in a vice and using a very simple jig keeps the guide in place on the tube while the silver solder is added. No measuring or guides, just fitted with eye sight.
This was actually turning into a busy day but it was hard not to just chat about all things cycling in the 70s and 80s with Dave; our respective shops were only a few miles away from each other and it was great to remember all the races, clubs and names of the time!
However, getting back to building my frame, I had to cut the slot in the back of the seat tube to allow the lug to do it’s job and clamp a seat pin.
Dave finished off the top of the seat lug while I had another look around the workshop.
Before I started to tackle the bridges, we checked the rear alignment, which was only slightly out to one side, a quick push and pull and the frame was straight. The front alignment was spot on as the seat tube and head tube are held in line by the jig during the brazing. At this point I completed the brazing of the rear dropouts to seat stays which had just been held with tacks.
Before I started the next task, Dave had warned me that it wasn’t the easiest. It was time to fit the brake bridge. So what’s so difficult about that? Well, lots!
First off, because this is a custom frame, we can do what we want, so instead of using the metal clips you get with mudguards to fasten them, I was going to make and fit a bottle boss into the bridge to do that. That was the easy bit. The bridge has to be cut and angled and mitred and made to fit into a specific space and height while keeping the brake bolt hole in the centre. Cut it wrong and it will be at the wrong height or lop-sided and useless! The height of the bridge is determined from the radius of the wheel, tyre size and clearance; and yes, Dave has special jigs to hold it while it is brazed into place.
I must admit, I was pretty impressed with my metal work to get this to fit perfectly. If that impressed me then I was going to be even happier with the chain stay bridge. Dave handed me a 3″ off cut of seat stay and said that it was going to be the chain stay bridge. Again, I would customise this and fit a bottle boss fitting to secure the mudguards.
Lots of cutting, lots of filing, lots and measuring and lots of checking and the bridge was made.
Last thing to do today was fit some pannier rack bosses to the rear stays, and yes, there is a jig to do this which places the bosses in exactly the right place.
I think that was loads completed in a day which meant that the last few hours on day 5 would be spent cleaning up the frame ready to paint. I was now really thirsty so it was time for a pint!