first time posting. I've lurked for years and have found answers to a ton of questions, but can't seem to find a discussion on one specific thing. I have a 1980s Peugeot Elan—I believe from scouring old catalogs it's from 1987. It's a low-end model (Carbolite+ frame). I bought it about 12 years ago in London for around 100 pounds. I've long since bought a few additional bikes, but this one has sentimental value so I want to keep it around but also give it a purpose my other bikes don't cover, so I've decided to convert it to a single-speed just for daily riding around the neighborhood. Because it's not a high-end model and already has some new parts on it (different wheels, new cassette, new pedals and seat, etc.), I don't have any special desire to keep the components vintage—just want a simple, reliable, and fun bike that encourages me to take it out instead of the others from time to time. I bought a pair of Shimano Sora dual-pivot brakes for it, which are set up for a recessed nut. After reading here and elsewhere, I decided to use the front brake as the rear and I ordered a Jtek 70mm replacement bolt to put into the rear brake so I can use it on the front. Seems like an easy solution, but when I tried to remove the original pivot bolt, I had no luck. I could get it to turn maybe a quarter turn and then it stopped. Because I was impatient, I went for more leverage instead of stopping and thinking it through, and I pretty quickly stripped the bolt with an allen wrench. I then realized that the fact I could move it partway but no more probably meant something is securing it and noticed a little screw on the caliper. I suspect that needs to be removed (or just loosened?). Because I also bought Sora brake levers and I think it would look better if the brakes and levers match, I'd like to try again with another Sora, but don't want to waste the money if I'm wrong. So I have two questions I'm really hoping somebody can help me out with: (1) Is it in fact possible to remove the pivot bolt from Sora brakes? And (2) Am I right about that little screw being the key to removing it or am I way off?
1 Answer
Presumably this is a BR-3400. The little screw is a set screw that indeed keeps the pivot bolt from being able to come out. I don't know that I've messed with one on this particular brake, but a lot of dual pivot brakes have set screws of this nature, and generally the stumbling block with them is the tool fitting is tiny, like a 1.5mm or 2mm allen, but there's threadlocker applied such that even if it's only a medium strength variety, it's enough to make it easy to strip the tool fitting. It's basically in there semi-permanently.
I would start by seeing if the set screw wants to come loose with normal pressure on the tool, but don't force it. If it doesn't come off easily, use a hair dryer, heat gun, or (least preference) lighter to loosen up the threadlocker. You're trying to get the area pretty warm, not insanely hot (150C is basically the area where bad metallurgical things can happen, but you don't need to go anywhere near there).
To extract the pivot bolt once you do have the set screw loose, if it doesn't just spin loose freely, take two M6x1 nuts and lock them together on the other end of the pivot bolt, then you can use a wrench to drive it out even with its stripped head.
Put new medium strength loctite on everything when you re-assemble.
