I'm fixing up a step-through frame that has cantilever brakes. I'm having quite a bit of trouble getting the rear brake right. The cable routing goes from the lever along the down tube, under the bottom bracket, up the seat tube and over a pulley before it gets to the straddle cable hanger.
When I get the brake adjusted, there's so much springiness in the cable as it goes over the pulley that the lever uses about half its pull distance just taking out the springiness before it starts taking up any cable to actually actuate the brake. The lever ends up bottoming out before the brake is applied fully.
I'm using the brakes that were on the bike, but with different levers. The levers I'm using came off a bike with cantis as well. I'm assuming they would be appropriate for this use.
I've thought of taking the cable off and prebending it in the area where it passes over the pulley. Other than that, I'm not sure what to try. Any suggestions or tips would be greatly appreciated.