Easy when you know how

[guzziownr]

Some may remember my complaint that my rear pads were wearing unevenly, a problem I tracked to the rear caliper being off center. I ordered new pads from MG Cycle and did nothing for a while as I couldn't figure out how to move the caliper closer to the wheel relative to the disk.

 

I was visiting the Erik Green the other day and described my problem. He gave me a pair of Brembo shims and explained (as if to a retarded child) how I should put them between the caliper and the carrier on the two securing bolts.

 

Easy Peasy right? It took a little doing because you have to loosen the rear axle, remove a pin and small block and rotate the carrier to get at the caliper securing bolts. Then, once the shims are in place and the new brake pads are in, you have to secure the carrier to torque the bolts. Then, ah, assembly is the reverse of disassembly.

 

I am happy now, because I have fresh pads in and my caliper is centered.

 

 

DW

[Guest ratchethack]

Thanks for the interesting post, GZNR.

 

I've been wondering why I seem to get uneven pad wear on the rear brake -- yet in my case, the disk is perfectly centered in the caliper.

 

Seems to me the hydraulic pressure on each brake piston should be the same and even things out perfectly. Every disk brake I've ever had -- every bike, every car, including the Brembo fronts on the Guzzi seem to work this way and give even wear.

 

Where's Dan the Brake man?

[dlaing]

 

I've been wondering why I seem to get uneven pad wear on the rear brake

Could it be the carrier is flexing or less likely, damaged from overtorquing the axle???

If flexing, one would predict the leading edge of the left pad and the trailing edge of the right pad would wear more.

But maybe a more rigid carrier would be something someone could market.

Of course it is no big deal, right?

[guzziownr]

Thanks for the interesting post, GZNR.

 

I should get that as a plate, I bet it's not taken.

 

 

I've been wondering why I seem to get uneven pad wear on the rear brake -- yet in my case, the disk is perfectly centered in the caliper.

 

Thanks much Ratchet soon you will be telling me there is no Santa Claus.

 

Seems to me the hydraulic pressure on each brake piston should be the same and even things out perfectly. Every disk brake I've ever had -- every bike, every car, including the Brembo fronts on the Guzzi seem to work this way and give even wear.

 

My limited experience with juice brakes led me to this conclusion. WE will see if they wear evenly now. To test my theory I will stop the bike at least once during every ride.

 

DW

 

Where's Dan the Brake man?

[Dan M]

Where's Dan the Brake man?

 

 

Who???

 

On a opposed piston set up like this, hydraulic pressure will be equal on both pads regardless of position. It has to do with piston diameter not how far the piston is out of the bore. Unequal wear is usually due to the pad hanging up and not sliding freely. It's the same reason our rear brakes have the tendency to groan when dirty, the pads don't retract evenly.

Now if your caliper is cocked on an angle, and not in alignment with your rotor, that is a different kettle of fish. Then you will get a tapered wear pattern on both pads.

[GuzziMoto]

What he said. All I can add is that it's normal for the leading edge of the pads to wear more then the trailing edge, and that many rear brakes (and some front brakes) only have pistons on one side of the disk. When that is the case, it is very important that the caliper slide freely side to side(like butter).

[mike wilson]

It also helps for the pads to be relatively loose in the caliper. A healthy "clonk" when applying the brakes at walkabout speed means that the pads are free to move and not being inhibited from backing off the disk when pressure is released. Unfortunately, that often means that they are free enough to squeal like a tourist in the backwoods of Tennessee.

[Dan M]

Unfortunately, that often means that they are free enough to squeal like a tourist in the backwoods of Tennessee.