Monday, August 13, 2012
Old parts new lessons
Of course brakepads are out of alignment and the caliper doesn't work right.
Of course I took the hex wrench to it without further thinking...
And but of course things can only go from a state of F*ckup to rapid blinking WTF mode!
Still thinking how bad can it be if I am comfortable prying apart "high end" suspensions and yakking on optimizing disc brake installation ...was at that moment, between stringed expletives tugging and twisting at the cables (no, the plural in cables is not a typo-- remember what a cantilever looks like, yeah each brake had more than one cable?)...... only to be approaching it all wrong.
One side of the rear caliper was simply dead-- not returning to center no matter how I tried to coax the damn thing..ramming the adjustment set-screw did jack.
That's when I remembered vee-brakes with those spring arms. from here on Ha easy fix!..
Going from front to back-- of course the flipping spring arm couldn't be found because there was none. No such thing as a spring arm... only then did it dawn on me how long it has been and I just totally forgotten what a cantilever brake is. My moment of rapture just ended with more expletives, attaining paragraph lengths by now.
Finally found!. Yes, those cantilevers antiquated enough where the springs are actually spirally coil-looking things (ok just what am I trying to describe here!) fitted over the brake boss where it requires aligning some inner plates within the calipers and gingerly put everything together for that "springy" effect.
Sometimes there are just no short cuts. Rip everything apart, look at all the unmarked orifices and bits, poke them around, flick a nub or two and see how they click. Then inserting those protruding bits in and work them further with more filthy fingering . Of course everything would start getting all and greasy by now and finally a cussing climax with spewing bits in every which directions before you can clamp the whole shebang down..... In this case its the sandwich of caliper with corectly oriented plates, spring plus retainer cap onto the brake boss decided to show me the bird before they got SlaMmed with the original but slightly rusty M6 bolt.
Third try and bingo-- Locked down and finally the bloody thing snaps back when pushed against the rim.
And whaddaya know-- somhow that makes the ding-a-ling set screw working too!. Ok, everything centered nicely, with one final adjustment to the cable and.... DONE.
While the likes of popping off "complex" shock damping and ogling shim stacks and discussing to no ends over [choose a beverage of choice] on forums would be the norm these days... it was a humbling 45 minutes session having some old simple technology with far fewer bits laughing in my face.
Thinking back now to how those metal plates and a spring works in combination gave me an idea on a DIY mod that had me stumped as I needed a kind of return action on some "modern" parts on another bike...
[update]... just as i came back to edit some typo above, all things cantilever seems to be flooding a typical Monday .. from one of the blogs I follow http://velo-orange.blogspot.sg/2012/08/breaking-it-down-grand-cru-cantilever.html
Posted by anvil_den at 12:09 AM