2001 Softail Standard here, FXSTI.

The pads I installed are the OEM sintered bronze material but the rear brakes have always been tricky. A little aggressive pressure on the rear pedal locks up the rear wheel really fast for a disproportionate pedal travel--in other words, the first may 3mm of pedal travel there is very slight "grab" at the rotor but much more pedal after that and the clamping force of the pads against the rotor increases unpredictably.

I know all-organic pads wouldn't be so aggressive but they make a real dust mess of the wheel. Anyone else had better results using rear pad brands or materials that aren't so aggressive? Has anyone found a bolt in replacement rear master cylinder for the softail that has say, a larger piston cross section thus reducing the aggressiveness of the pedal pressure?

I've heard of opening the bleeder valve and introducing air into the brake line to reduce brakes "grab" but that would seem to me a very inconsistent way of addressing the problem (wouldn't perform the same every time brakes are applied). Yes the rotors are not warped and yes the rubber brake hoses are in fine condition/replaced with new.

As an aside, I'm a very experienced rider (well over 400K miles and 5 different bikes of different models) and never had this problem with non-Harley motorcycles. Seems particular to the softail rear braking system.

 

On my old bike. I bought Lyndalls gold pads. I had RC Components wheels and was worried about dust. They were good. They didn't grab to much unless you got on them and no dust!! You should give them a try . It could be a easy solution to your problem... swifty

 

I never heard of introducing air into ANY brake system! It goes counterproductive to everything I have ever learned about ALL braking systems! I would be more suspect of a bad caliper or master cylinder, leaning more towards the caliper first. I would first try pulling the caliper and rebuilding it. By mentioning that the rear brakes have "always being tricky", has the bike always done that?

 

If you haven't done a complete brake system flush, you should. 16 years collects a lot of crap. And air in the system is bad.

 

plus 10, sticky calipers have caused a lot of grief.

 

On a 01, I would rebuild everything to OEM new. Would forget trying to adjust by squeezing air. Adding air may work slightly since air compresses unlike brake fluid but number one, it would introduce corrosion that much faster and probably would work out as it sat.

I do know for sure, if you get distracted and when that time comes that you really need to get a hand and foot full of brake, that big change catches you off guard and you slide fwd slamming that foot brake.

Closest I came to eating is was in a left hand turn. The left lane was held up by a trash truck. Just happened to notice in the turn, a guy had his hand out waving to a car off the road to my right to pull in front of him. Neither was looking in my oncoming direction. Sure enough, next second, he was in front of me feet away. Hit the brakes, slid fwd and slammed the rear brake pedal. No kidding, rear shot out in the left-hand turn to the right and pointed me in the opening in front of the man waving. The other car saw or heard me and stopped and I like went into that open space, turned it back right and round the car in my lane and on down the road.

You just need to keep the brakes and tires right and practice. Drive defensive and sometimes just be lucky. Fwd controls makes it worst.

I say the above since I do not agree the rear is too strong on a Softail. Normal ever day driving on mine using both brakes uses way more front. Since my last rebuild with OEM , my rear pads are twice as thick as the front. But just my opinion and how I drive.

 

I've owned two softails, and never had a brake issue. Sounds like you may have sticky calipers, or other issues with the system. Rebuild and flush. There are few adjustments of disk brakes, adding air is definitely not one of them.

 

thanks guys
this isn't a problem with "sticking" rear brake....the caliper pistons retract just fine and I flush the entire brake system with Drag Specialties DOT5 fluid every spring before riding. All and always good points though, thanks.

The entire braking system is fine, it's just the proportion of pedal travel as relating to the arc of the foot pedal. 3mm maybe is "soft" braking and suddenly beyond that it wants to "grab" hard. Not much margin at all there ! The master cylinder is just fine, all is good--it's the setup I'm looking to modify and was wondering if anyone found a larger piston master cylinder that would bolt up or? I'm not wanting to shorten the brake pedal (although that is always one solution to reducing the pedal pressure needed if you know what you're doing with welding reinforcements etc).

I might give Swifty's post for the Lyndall gold pads a try but don't stop there....I'm all ears (and eyes).

 

Wait til ya don't have any rear brake and you'll appreciate what you have. Sounds like you just need to go thru the system, kits for the caliper/master cylinder inexpensive. Try and remember you flush the fluid every other year minimum.

 

Bigger piston would lock even sooner. No reason for a properly operating system to lock-up without intentional pressure applied. Does your wheel turn with NO drag, when off the ground? Do you get a full pedal travel when bleeding?
If only 3mm of travel you might want to check the adjustment nut @ the MC, sound like it is too far in and MC piston doesn't have full travel.