Filed In: Process
Father/Daughter Project - Part 15
Friday, January 31, 2020 | Chris Blandford
All right, BRAKES!
I’ve decided to go ahead and put hand brakes on this bike, as originally planned. I went back and forth a bit, but I think this is the right decision. I can always add a coaster brake if need be; it’d be tougher to go the other direction.
Brake bosses, I’ve found, are straightforward. Here I’m using a Paul brake (see Nerd Note A). For any Paul rim brake, I’ve used the simple, spring-hole-less Paragon bosses. To get them located, I install them onto the brake arm itself, insert a wheel into the frame (see Nerd Note B), and place them on the frame/fork. I mark the location with a Sharpie and that’s that. I usually check my placement against the recommended distance-from-axle spec, but--imagine that--the spec for brake stud distance for a 305 BSD rim isn’t listed in any of the obvious places.
Next I cut down and miter the studs to fit the fork blades/seat stays. I’m sure that there’s a good reason most cantilever brake bosses sit so far off of frames. Because I don’t know what it is, however (and stuff like that drives me crazy) I can plead bicycle-ignorance and do what I want. I cut these down to a size that makes sense to me, so that the brake arms sit as close to the blades/stays as possible. I miter the bosses so that, once attached, they’ll sit ~80mm apart. I wouldn’t want to do any of this without the actual parts on hand.
One note: on this bike I’m running the rear brake on the underside of the seat stays. The swoop of those stays provides enough clearance (from the chain) to allow for this, and I think it looks nice. Almost like I was planning to do this all along. For the record, I was not.
Once mitered, I load these into my brake boss jig (from Nova), double check everything, and drill small breather holes in the seat stays and fork blades. Then I clean, flux, and braze them on (see Nerd Note C). I use 1/16th bronze rod and my 203 tip for these, just like dropouts.
Double check by installing the brake arms, soak, and finish the little fillets. All good.
Next up: final braze-ons.
Nerd Note A: I installed a pair of Paul Minimoto v-brakes onto the little Cleary bike and let Mathilda have a go at giving them a good squeeze. I’m actually really surprised at how much force she can get on them with the little Tektro teeny-reach brake levers. When combined with the adjustable Paul spring, I think I’ve got a winning setup here.
Nerd Note B: Since this frame uses track dropouts, I installed the drivetrain while locating the rear bosses. The rear axle is going to end up sitting about dead center in the dropout, which I feel good about for multiple reasons, but especially in consideration of the boss placement.
Nerd Note C: I brazed the rear studs on with Filletpro silver flux and rod. I noticed while cleaning the four studs up that one of them looked extra shiny. Sure enough, when tested with a magnet, one of the four was stainless. Not sure how that happened (I must’ve ordered a pair of stainless bosses a while back?), but I’m glad I caught it. Rather than re-miter another stud, I just used the Filletpro. The fork studs I brazed on with bronze.