long drop brakes
gbb said:
I think some (maybe a lot) of the braking force is lost with flex in the long arms of long drop brakes.
The force clamping the brake to the rim is reduced because the lever ratio is reduced with long drop brakes (the brake pad travels further for the same lever travel). The change to the mechanical advantage is a bit like that from using a higher gear in the drivetrain, where the wheel turns further for the same pedal movement, but the effort required to accelerate is greater.
Sheldon Brown's website is a great resource for cycling info and his article about cantilever brake geometry is worth a read -
http://sheldonbrown.com/cantilever-geometry.html
Assuming that your brakes are already adjusted so that you can't depress the lever all the way to the handlebar, you have a few options:
- develop your grip strength to a level that will make people think twice about shaking your hand
- replace the lever with one designed for long throw cantilevers
- replace the brake with one with a shorter drop or disc brakes (if the frame will accept them)
I presume that you are using long drop calipers in order to use smaller wheels than the frame was designed to take. If you don't want to use larger diameter rims, an alternative is to fabricate a new mount to allow standard brakes to work with non-standard rims. Again Sheldon Brown has some info on this - see
http://sheldonbrown.com/home-drop.html. It may not be absolutely clear in his instructions, but he uses two flat bars and spacer washers (instead of one flat bar) in order to reduce bracket flex, which would reduce the braking performance inthe manner you described.
Personally, I would use standard brakes and rims, but if you want the smaller rims for frame geometry or other reasons, I would try to find some levers designed to work with these brakes, with the normal brakes and home made mounting bracket being my third option (I presume that disc brakes are not practical).
