Motorcycle Repair: 1976 CB554, coefficent of friction, honda rotors

Question
Original owner.  Hand brake does not cause disc brakes to grab the brake disc tightly enough to stop cycle.  Have thoroughly cleaned parts.  No leaks in system.  No air in system.  Brake pads are not new, but decent.  Used DOT 4 instead of Dot 3 brake fluid (recommended).  Any idea what could be wrong?  Where do I go to get replacement parts as Honda dealer does not carry 1976 parts.  Thanks!  

Answer
Pete, nice to hear from an original owner of a 30 year old Honda classic.

Honda's OEM pads are pretty durable and last for 10-20k miles, depending on how you ride and what kind of care it has had. So, first question is are these still the original pads? If not, did you get the replacements from Honda, as well?

If you go to www.sohc4.us site, you will probably find a lot of other complaints about Honda's single piston brake calipers. They really don't stop very well, unless everything is about perfect and then they are are still wanting. OLD pads will get very hard and lose their friction surfaces, especially when they get glazed over.
EBC or Vesrah pads usually do a good job and are fairly cheap. You may be able to find Ferodo green lined pads somewhere, which are for racing and have good friction, but a short life span. http://www.vintagebrake.com/

If you are sure that the hydraulic aspect is up to specs, then the issue is friction or lack of it! Honda rotors were mostly stainless steel, to prevent rusting, but they have a low coefficent of friction when you use that kind of material. The rotors also tend to glaze over which makes them all shiny and again the friction surface is compromised. You can take a small electric sander and rough up the surfaces, gently but evenly on both sides or if you can find a machine shop with a blanchard grinder, have them grind both sides flat and smooth. Brake lathes don't work well on these rotors because of the stainless composition.

Some of the cafe racers, built back then, used a double disc brake system, which added weight, but gave a lot more braking power. Honda's later twin piston calipers offer a lot more grab than the early single piston units.

They are what they are, due to design limitations, but flat, smooth rotors and fresh pads should get you stopped better than what you have been experiencing recently.

Bill Silver