Originally Posted by
sjanzeir
Jeff Neese - you're confused about a lot of things here. The fact that they're called "linear pull" brakes has nothing to do with the length of the the V-brake arms (the ones down by the rims.) Both "regular" (105-108mm, sometimes longer) V-brakes and so-called "mini" V-brakes (around 85mm) are "linear pull" brakes. The "linearity" comes from the fact that the cable and cable housing actuate a given V-brake by "directly" pulling the brake arms together and squeezing - or pinching, if you will - the rim. Hence the other name for V-brakes: "direct pull" brakes, meaning no intermediate cable between the main cable and the brake arms like the one cantilever brakes have.
And none of the above has anything to do with the way a typical flat-handlebar brake
lever works. Which is why I could (and I did) have two different bikes that used identical brake
levers, with one running rim V-brakes and the other running mechanical disk brakes. Even though the levers applied the braking action through a liver on the caliper that pivoted around an axis, absolutely no one would've called the levers on the bike with disk brakes "arc pull!"
Which is why, just as there are long-pull and short-pull V-brakes, there are also long-pull and short-pull mechanical disk brake calipers; this was necessary for the industry's transmission from rim brakes - with V-brakes having become the most ubiquitous type of rim brake outside of road bikes - and the exploding popularity of entry-level (with no shortage of premium) mechanical disk brakes. What needed to be matched is the amount of pull at the lever (long vs. short) with that of brake being used (long-pull or short-pull, regardless of it being a rim V-brake or a mechanical disk brake caliper.) That's why there are "long-pull" levers (in that the blade's pivot is farther away towards the handlebar from the cable barrel anchor) and "short-pull" levers (the two are much closer to each other.) SRAM's/Avid's FR-5 brake levers - and the kajillion clones/knockoffs simplified things for both manufacturers and consumers by being "medium-pull" brake levers that worked well (whether equally so or not is up for debate) with both long- and short-pull brakes - no matter what type they are.
I'm not confused, and I agree with most of what you're saying (although again, some of this is semantics). It's about the amount of pull at the lever, and matching that to the brakes. It's the cable pull and mechanical advantage (leverage). Something like Travel Agents simply change the cable pull, and in so doing change the mechanical advantage to be compatible with long-pull brakes.
What I was clarifying is that it has nothing to do with the physical orientation, horizontal or vertical, of the cable with regard to the brakes. It also has nothing to do with the brake performance being "linear" over the life of the brake pads, but someone else picked up on that one.