[Richard Strange]

I was just at the bookstore thumbing through the latest issue of Classic Motorcycles and read a short article promoting a rear brake cable conversion kit from Dime City. The rationale for this $60 fix was to eliminate unintentional actuation of the rod controlled rear brake during swing arm compression. The author said that the effect was not enough to lock rear wheel, but would “get your attention” when navigating a hard turn with a dip (a bit hairy, in any case IMO).

This never happened to me or even occurred to me in my 350 riding experience, though I have never been an aggressive rider. I certainly understand the mechanics of the “problem” and it is a reason not to adjust rear brake too tight, but has anybody else noticed this?

 

[Lefty]

My guess is it's marketed towards the cafe racers. Oftentimes with rear set foot pegs they accuate the brake with a bent rod pivoted off some part of the lever. The farther the rod pivot is from the swingarm pivot, and possibly the lengths involved will have the effect of transferring swingarm movement to the pedal. If the cable is anchored to something that moves the same as the brake or swingarm, problem solved. I made one for my racer back when that used a straight rod pivoted throughthe frame and thought I was really some great designer till I rode it. Switched to a cable system. The reason you don't notice it on a stock brake is because the rod pivot is very close to the swingarm pivot. And they both move pretty much the same from bumps.

 

[phil71]

that should only happen if the brake arm is installed at the wrong angle to the centerline. That's why the brake actuator arm is always trailing, so upon suspension compression it should ONLY ever 'relax' brake pressure. Sure, not ideal, but better than lowsiding because of a lock up. If you're racing the thing, a cable is a big help, but a properly angled rear brake should be fine