Should be .040 gap between pad and disc when relaxed. Mine are dragging on the disc. Discovered when I brushed my hand against the front after a ride and found it too hot to touch. Checked the gap and found both front and rear brakes are dragging, causing overload to engine and poor fuel mileage.

Took brake bodies off, pressed the brake handle/pedal and they're not retracting at all. Probably full of gunk inside, so will tear down and rebuild.

 

.040" is a mile in pad travel terms. I would expect no more than .005 or less depending on rotor runout. Even .005 with fixed calipers would be a problem with shuddering and vibration upon brake application.

Our brakes don't have retraction mechanisms so the gap should be immeasurable on perfect rotors.

Hot to the touch may or may not indicate a problem depending on a variety of things. Jack the bike up and spin the wheel by hand. It should not drag or drag only very little.

 

The manual says ".040", and spinning the wheel by hand doesn't represent riding conditions. There is a w-shaped spring inside the mechanism that is supposed to retract the pad away from the disc. My bike was humming loudly at 40 mph and after I cleaned out the bodies the hum went away. Also discovered oil was 2 quarts low, most likely caused by engine overworking to compensate for the brakes dragging.

 

The W shaped spring is for anti-rattle and holds the pad firmly against the piston. They can be safely omitted. I bent mine out slightly to ease pad installation.

I don't know what the .040 you're seeing refers to but I assure it's not a running-condition air gap between friction surfaces.

 

Didn't you already ask that question about the .040"?

yeah, here it is...
https://www.hdforums.com/forum/dyna-...ds-no-gap.html

And you were told then that the .040" mentioned has nothing to do with the clearance of Rotor-to-Pad material...don't you read the responses to your own questions?



EDIT:
It's the remaining pad material spec


.

 

Further....if your brakes were dragging so bad as to cause oil consumption you would literally be on fire within a mile or two. You wouldn't be able to back up and your clutch would be shot from revving it up to pull away from stops.

 

So you're saying it's impossible for brakes to drag. Not buyin' it.

 

Something tells me your oil consumption is closely related the excessive vibration you're feeling. Your engine needs a thorough inspection.

 

Absolutely not. I've had brakes that were dragging from binding caliper halves. They can get so hot that seals melt or fluid boils....and I never felt a thing in my butt or feet from dragging...until I had no brakes at all... Massively excessive brake dust and hot rotor (like hotter than the exhaust) are easy giveaways. Get the wheel in the air and it's immediately apparent when it won't spin freely.

 

Not to bicker, but if there was enough brake drag to cause the overworked engine to burn two quarts of oil that wouldn't otherwise have been burned, I highly doubt you would have been able to roll the bike around at all.