unworthy1

Folks, I'm usually over in the C&V sub-forum, but have a question that I'm asking here, too: I offered a small pile of used Scott Pedersen SE cantis to another guy there (I know they are controversial, but he's buying, I'm selling, not endorsing) but neither he nor I can say by looking which go on the front and which on the rear.
That is an important detail cause if you mount them opposite the intended position they will Self DE-Energize, giving you weaker braking force rather than stronger....there's no markings to ID these as either F or R. At least nothing I can see, can't find any info about that on the internets or in these archives.

Help!

and Thanks!

(some pics here) https://s55.photobucket.com/albums/g1...anti%20brakes/

kenhill3

Here's what Sheldon Brown had to say about self-energizing cantilever brakes, in the context of tandems:

Self-Energizing Cantilevers

Because of the myth that conventional cantilevers aren't strong enough for tandem use,some people favor Self-Energizing cantilevers. These don't have a simple pivot,instead,each arm moves on a steep multi-start screw thread,so that as the shoe approaches the rim it also moves forward. When it rubs on the moving rim,the forward pull tends to increase the inward pressure,providing a "positive feedback." This design can apply greater braking force for less finger force than a conventional cantilever,but it is difficult to modulate it. The original Scott Pedersen SE brakes were available either for front or rear use (opposite direction threadings), but when Sun Tour bought the design, their legal department vetoed the front version, so only the rear model was made by Sun Tour. I advise against the use of Self Energizing brakes, because they make it too easy to lock up the wheel.

unworthy1

ken, I am aware of what Sheldon thought of the self-energizing brake, and I never mounted or tried them myself...just selling parts I bought at a swap meet cause they looked "interesting" at the time. I wanted some cantis for a cyclocross-turned-commuter project and have tried several brands on that bike, but never these.
I'm down to putting them on a boss (probably a fork) and working them to see how they "tighten" to an imaginary wheel...and then I'll mark them F or R so nobody has to guess again! Can't believe that Scott coundn't bother with a tiny stamp or addition to the tampo decal when they made them...but maybe it's cause they are ALL intended for rear use only

kenhill3

Yeah, I posted Sheldon to show how the brake functioned, and from that description I would indeed do like you and mount them to observe rhe action and identify which is which. Good thing ya gots somebody interested in them!

Double0757

I have them in my tandem (Belinsky), since 1991, the last brake shoes I used are a no brand shoe and now I don't remember what kind should I buy? I want to put kool-stop brake pads, I know they are Cantilever, but don't know what kind to buy. Does anyone know?

Thanks! Double O

P.S. I locked the front wheel one time going down hill, scare me more than the stocker, however nothing happen except a big flat spot on the tire. After this I'm always careful with the front brake and had no problem since then. If you are aware of it it can be avoided. They are very good brakes other wise.