Front brake really firm?

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sbaugz

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Just completed a build.
1981 special with stock front brakes, master and caliper.
I did a rebuild of caliper with mikes parts. Master did not need rebuild.
Using a braided eBay bought brake line.

Got them bled, and the lever is super firm. There is no play at all. I pull in lever just a small amount and the brakes are grabbing at full power. All my other bikes have a 1/2" or more of lever pull before it even starts to get firm and grabs brakes. This xs is super firm from get-go. Probably the firmest pull I have ever experienced. Having never driven an xs, I don't know how they should feel but despite having a firm feel at lever, they don't seem to be the worlds greatest brakes as far as stopping.
Thoughts?
 
If your used to the function of modern sport bike brakes then these do feel like crap. When they came out these bikes had about the best braking out there.
It does seem that they are not right. On the lever there is an adjustment screw. It lets you adjust the lever play so it has free play before it starts to push on the piston in the M/C. If it's adjusted to tight it will start pushing the piston as soon as you pull the lever. This may be part of the problem.
The stock brakes are a bit wooden. This means the lever pulls to hard and you have no feel of how the brakes are working. You keep pulling and suddenly the brake locks.
One way to fix this is to use a smaller bore M/C. An 11 mm M/C is recommended for the 77 up single disc brake.
The stock 14 mm bore works well with a dual disc brake.
Either way you will greatly improve the braking.
I know they make brake lines in different sizes. For racing applications they use a smaller inside diameter lines. I think they are 2 mm inside. For street use a 3 mm line is recommended.
The smaller lines actuate the brakes quicker but can slow the release of the caliper. This can lead to the caliper binding, causing excess heat.
Other than these things I can't think of anything else that could be your problem.
Leo
 
With the 11mm master, my single disc front has the feel, if not the all out power of my SV650 brakes. Very satisfied with the lever action
 
What pads are you using? The Ferodo Platinums will give more "feel" but less initial bite. Squeeze the lever hard though and they stop very well.
 
The braided line really wakes up the system. After you adjust the lever play with the screw you might need to just get used to it with time. I put a S/S line on and drilled my rotor. It made a big diference and I like it.
 
Last edited:
5twins said:
What pads are you using? The Ferodo Platinums will give more "feel" but less initial bite. Squeeze the lever hard though and they stop very well.
Click to expand...

Honestly not sure. They are from previous owner. Might actually be stock pads still since bike only had a couple thousand miles on it.
 
A couple of thoughts. In your initial post you said the M/C did not need rebuilding. If the small passage in the reservoir that allows for pressure relief is plugged your brake will not release properly. Also, if the square edged seal in the caliper is not working correctly the piston will not retract. For what it's worth.

roy
 
What Royboy said. That tiny hole allows the system to equalize, with it blocked (common) the pads won't retract fully, the rotor will heat up, the pads expand and eventually the front brake will bring everything to a screeching halt. The master cylinder ALWAYS needs rebuilding unless it has been done very recently. (rare)
 
..... or bead blast them. That's 3M's recommendation for cleaning glazed pads and shoes. It does a wonderful job .....

BlastedShoe.jpg
 

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