Anyway, I should have just linked Sheldon, whose descriptions and advice are always the best: https://www.sheldonbrown.com/cantilever-geometry.html
On Wednesday, October 21, 2020 at 2:02:40 PM UTC-7 S wrote: > Maybe we are talking past each other or interpreting that passage > differently? To me, the point is not about pad angle, but arm/wire angle. > You want a good arm/wire angle at the point where the pad contacts the rim > and washers can help you achieve this. For instance, keeping all else > equal, if you use fewer washers, the pad starts farther away from the rim, > hence the arm needs to swing farther in for the pad to contact the rim, > increasing the arm/wire angle and decreasing mechanical advantage. I think > this is easiest to visualize with V-brakes, as the wire remains horizontal. > > On Wednesday, October 21, 2020 at 1:29:38 PM UTC-7 lconley wrote: > >> "I try to make this slotted part of the arm be perpendicular to the brake >> pad post when the pad contacts the rim. Why? Because this lets the pad >> hit the rim as squarely as possible. Too far past 90 degrees and the brake >> loses power (especially true with v-brakes) and when the arm is past 90 >> degrees, it’s on its way to promoting the pad diving under the rim." >> >> Geometrically this is just plain false. The brake pads have spherical >> washers that allow, within limits, the brake pad to be perpendicular to the >> rim whether the arm is slanted in or out or perpendicular. The geometry of >> the pad to the rim to the pivot point is constant. The pad is ALWAYS headed >> in a downward arc relative to the rim because braze on pivot point is >> outward of and below the rim surface, even when the brake pad post to brake >> arm attachment point is moving up. >> Pretend the braze on pivot point is the hub of a very tiny wheel to the >> right and down from the braking surface. As the tiny wheel rotates >> counterclockwise, the spokes on the left rotate down as the spokes on the >> right rotate up. >> >> Laing >> >> >> On Wednesday, October 21, 2020 at 4:03:06 PM UTC-4, S wrote: >>> >>> I don't see how this general idea is wrong or "misinformation": >>> >>> "I try to make this slotted part of the arm be perpendicular to the >>> brake pad post when the pad contacts the rim. Why? Because this lets the >>> pad hit the rim as squarely as possible. Too far past 90 degrees and the >>> brake loses power (especially true with v-brakes) and when the arm is past >>> 90 degrees, it’s on its way to promoting the pad diving under the rim." >>> >>> And the relative position of the straddle cable is key to making cantis >>> work. So anything that affects that, including washers, is important. >>> On Wednesday, October 21, 2020 at 12:16:49 PM UTC-7 lconley wrote: >>> >>>> Sorry, but that article is full of misinformation as are many articles >>>> on cantilever brakes. The brake pad rim contact point to cantilever pivot >>>> point is constant regardless of where the pad washers are - it is a fixed >>>> distance. It is fixed by the relative position of the cantilever braze on >>>> to the rim surface and does not change by changing the pad washers or even >>>> brand of brake - the relative motion of the pad to rim is constant >>>> regardless of the shape of the metal in between. Changing the pad washers >>>> only changes: >>>> 1. the the relative location of the straddle cable attachment points >>>> to each other and to the straddle hanger >>>> 2. the amount of flex between the brake pad and the pivot point. >>>> >>>> Laing >>>> Delray Beach FL >>>> >>>> >>>> On Wednesday, October 21, 2020 at 2:06:56 PM UTC-4, S wrote: >>>>> >>>>> Although I have switched to using V-brakes, I agree that cantis work >>>>> well when set up properly. Has anyone linked this article yet? Good tips: >>>>> https://blackmtncycles.com/get-the-most-out-of-your-canti-brake/ >>>>> >>>>> I also agree with Ash that the model of canti can make a big >>>>> difference. >>>>> >>>>> I think technique may sometimes play a part in fork judder or >>>>> perceived lack of modulation when using V-brakes. Because of the greater >>>>> mechanical advantage, they require a much lighter touch on the levers >>>>> than >>>>> cantis or calipers. When I first switched to Vs, until I learned to >>>>> lighten >>>>> up, I nearly sent myself over the bars several times. Now I have no >>>>> problems. I find the feel of Vs very similar to mechanical disc brakes >>>>> On Wednesday, October 21, 2020 at 8:59:47 AM UTC-7 Mark Roland wrote: >>>>> >>>>>> I question the notion that these attributes represent a "significant >>>>>> advantage." My Trek 830 still has the original basic cantilever brakes >>>>>> from >>>>>> 1984. I don't think the pads, cables, or housing have been changed. >>>>>> Stops >>>>>> like a charm. Even after being under all that averse tension and >>>>>> compression for the past 36 years. Also cantilevers have been stopping >>>>>> tandems, loaded touring bikes, and racing bikes for many years. I get >>>>>> that >>>>>> people don't like working with them, But it's just another personal >>>>>> technology decision, like whether you want to use indexing, or >>>>>> electronic >>>>>> shifting, or friction. Cantilever brakes are effective when they are set >>>>>> up >>>>>> the way they are supposed to be set up. >>>>>> >>>>>> >>>>>> On Monday, October 19, 2020 at 10:06:14 PM UTC-4, Kainalu V. >>>>>> -Brooklyn NY wrote: >>>>>>> >>>>>>> Daniel's statement makes some sense- "but there are significant >>>>>>> benefits to long-pull brakes, both rim and mechanical disc, in that the >>>>>>> cable is under less tension so the cable stretches less and the housing >>>>>>> compresses less as a result." >>>>>>> That's enough of a reason to never use cantilevers again. I use Avid >>>>>>> Speed Dial levers for the adjustable pull built in to the lever. >>>>>>> Currently >>>>>>> all set on long pull and that's how they'll stay. Glad the last time I >>>>>>> spent a lot on cantilevers was 1990 >>>>>>> -Kai >>>>>>> >>>>>>> On Sunday, October 18, 2020 at 1:50:05 PM UTC-4 Daniel M wrote: >>>>>>> >>>>>>>> I will also throw out there that finding a long-pull lever you can >>>>>>>> live with is a preferable solution than Travel Agents. I'd sooner go >>>>>>>> with a >>>>>>>> short-arm V-brake than use a Travel Agent, but there are significant >>>>>>>> benefits to long-pull brakes, both rim and mechanical disc, in that >>>>>>>> the >>>>>>>> cable is under less tension so the cable stretches less and the >>>>>>>> housing >>>>>>>> compresses less as a result. >>>>>>>> >>>>>>>> Daniel M >>>>>>>> Berkeley, CA >>>>>>>> >>>>>>> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. 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