Front Brake weak

[dontlikeoc]

The front brake is really weak. When I apply the rear brake, I can feel the stopping but not with the front. Is this the way the late 1970's brake technology is? Or, what am I missing?

The calipers including the pistons have just been rebuilt and the pads are new from Partsnmore. I can see the pistons going in and out. I cleaned the spooge hole in the master cylinder. The lever is not spongy at all. The rubber brake lines dont look expanding when the brake is applied. I am using the DOT4 fluid.

[psycoreefer]

Something is not right, if the lever is hard and you can't feel the brake power then you need to look at your pads and disks.
Are you sure you put the pads on right, there is a left and right set. Does the rotor have grooves in it?

[Guy_b_g]

Are you positive you have the right master cylinder? If it is one from a bike with 1 front caliper it will be quite hard to get enough braking force...perhaps you have a bike with a linked brake system which has been modified? Or a bike with linked brakes and you are not used to the force required on the rear brake?

Shouldn't be, if it's a '79...

Has the front master cylinder been replaced with one of the newer ones for a linked system?

[Jerry]

OK, you have an '81 Special. IIRC this has the 'linked' braking system that was also used on the XJ. Rear pedal operates the rear and front left caliper while the front brake lever operates only the front right caliper. Because of this, you get less braking power using the front brake only.

There are two options: Re-plumb the front brakes so both operate from the front brake lever, or learn to always apply the rear brake first. Some on this list have chosen the former; I have retained the linked system on my XJ and take the later path.

Ther rear master cylinder has a proportioning valve that splits braking power between the front left and rear calipers so the back won't lock up before the front. This system is not adjustable.

Only the '81 Special/Midnight Special and the XJ have this sytem.

A couple other things that will help: 1. Replace the OEM brake lines with Stainless Steel (SS) lines. This will reduce the 'flex' inherent with rubber lines and gives a more positive feel to the system. 2. Install a set of organic pads if you are currently running metalics. The organics work better in normal riding conditions, the metalics are better in more aggressive riding where they can heat up a bit. Organics are also a little easier on your rotors.

My guess is that you are using only or mostly the front brake, and on a linked system this cuts down your braking power to 1 caliper. You need to use more rear brake until you decide either to stick with the linked system or change it over to the more conventional front / rear separate sytems.

[fredintoon]

The front brake is really weak. When I apply the rear brake, I can feel the stopping but not with the front. Is this the way the late 1970's brake technology is? Or, what am I missing? - - -

Hi dont,
even perfect XS11 front brakes will not have you pulling a "stoppie" but my XS11SG fronts work OK.
I have had no luck looking for hard data but it's claimed that the '81 XS11LH (Midnight Special) has a linked brake system similar to but not identical with that on an XJ11.
If your SH also has the LH linked brakes hauling in the front anchor only works one front disk; you gotta stomp down on the rear brake pedal to work the other front + the rear.
Check to see if your SH has linked brakes and if the dreaded PO didn't mix'n'match brake parts on you.

[DGXSER]

From the factory, the SH does not have linked brakes. Only the LH and the XJ had linked brakes from the factory. Not to say that a PO did not switch them out, so take a look.

As to braking power, yeah the XS11 is not the best braking system. I think my F150 crew cab may have a shorter stopping distance than my XS11.

[dontlikeoc]

Thank you guys. The possible linked braking system explains. Using the rear always felt like the brake is working in the front too. I will see if I can live with the way it is.

[trbig]

even perfect XS11 front brakes will not have you pulling a "stoppie"

I disconnected the linked brakes and currently run with just the right front caliper in the front... and plan on "Y"ing the line and running dual fronts at some point, BUT, under emergency braking, the bike will somewhat do a stoppie. Not the nice pretty raised up in the air type the kids do on the sportbikes, but a bouncing-up-and-down-ass-end-bouncing-side-to-side type that leaves the rear brake pretty much useless.

I have changed to stainless lines and the difference was night and day over the old rubber line. I had to totally re-learn the bike. But even operating with just one caliper, I can squeeze enough to induce a front skid if I sit back a bit. (And Keoki, I'm talking about on nice clean dry pavement.. not concrete with gravel on it..) How much more braking power do you need if it will do that? Sure, it would probably take less effort at the lever to do this if I ran dual fronts, but you can get plenty of brake off of just one IF it's operating correctly. If you can't get much pressure to the caliper, I would suspect air in the lines. The pressure goes to compressing that air bubble(s), not expelling that piston out against your pads.


Tod

[skids]

I lost some braking power once when I switched to some cheap pads found on ebay. Not all pads are created equal.