vibration while braking? (Not vibrating anymore, but now what?!!)

REDUC · September 02, 2009, 09:12:49 AM

Okay, now what do I do? I sanded my pads, scrubbed my disks with brake cleaner and scotch-brite pads, and put it back together. Took it out for a ride to bed in the clean surfaces. Let me elaborate: I accelerated to around 60 or so and braked progressively harder with each go to about 5-10. Did not come to a complete stop. Repeat 10 or 15 times, and came home. Threw the bike back up on the stands and noticed my disks now have a lot of pad material transferred onto them. And when I spin my wheel, it feels like the calipers haven't fully released their hold of the disks. Pads appear to be shiny, enough to pick up the reflection of my red from my frame. Any thoughts??

ducpainter · September 02, 2009, 04:12:10 PM

Do you still have the vibration?

REDUC · September 02, 2009, 04:24:00 PM

No. So I guess that's one thing down. Should I be concerned that there is a significant amount of drag in my brakes, that I don't believe was there before? I mean I have to spin the wheel fairly hard by hand to get more than a full rotation out of it. That just doesn't seem right. Where did I mess up? Am I overlooking something obvious?

stopintime · September 02, 2009, 04:30:12 PM

Maybe the pistons stick instead of moving freely, because of the washing?
I don't know what I'm talking about, but there should be some way of "lubricating" them (brake fluid?)

REDUC · September 02, 2009, 04:44:51 PM

I think I'll try taking them apart again and cleaning some more. Hopefully it's as simple as some gunk in there. I have to admit that I'm a little let down that "Stopintime" doesn't know what he's talking about with regards to brakes...

Thanks, though. I'll give it a try.

ducpainter · September 02, 2009, 04:58:29 PM

Quote from: REDUC on September 02, 2009, 04:24:00 PM
No. So I guess that's one thing down. Should I be concerned that there is a significant amount of drag in my brakes, that I don't believe was there before? I mean I have to spin the wheel fairly hard by hand to get more than a full rotation out of it. That just doesn't seem right. Where did I mess up? Am I overlooking something obvious?

If you want to mess with it pull the dust boots off the calipers and clean everything up and reinstall.

Personally, I doubt the drag is bothering anything.

REDUC · September 02, 2009, 05:15:15 PM

Okay, it just seemed excessive to me. As in unnecessary friction that the engine really shouldn't have to overcome to push the bike down the road. Also I'm concerned that the large amount of heat generated by said friction might cause some other issues, like brake fade, or even lock up? I don't know. I always thought that when you apply the brakes they should grip, and when you release they should FULLY release.

ducpainter · September 02, 2009, 06:09:38 PM

Quote from: REDUC on September 02, 2009, 05:15:15 PM
Okay, it just seemed excessive to me. As in unnecessary friction that the engine really shouldn't have to overcome to push the bike down the road. Also I'm concerned that the large amount of heat generated by said friction might cause some other issues, like brake fade, or even lock up? I don't know. I always thought that when you apply the brakes they should grip, and when you release they should FULLY release.

I don't disagree, but there are lots of things that can cause the drag...

and FULLY might be subject to interpretation.

If it's really as hard to spin the wheel as you describe it would be worth investigating.

I'd tap the calipers with a soft mallet, not rubber, to see if the shock loosens the pads.

If it works and the drag reappears I definitely would clean up the pistons...

but i wouldn't start ripping things apart just yet.

That's just me.

REDUC · September 02, 2009, 06:13:00 PM

Do the pistons come out as easily as the pads? They seem to be just hollow cylinders. I don't want to start tearing into things either. I just want to solve what I percieve to be an issue. I want my brakes back!!

ducpainter · September 02, 2009, 06:20:04 PM

Quote from: REDUC on September 02, 2009, 06:13:00 PM
Do the pistons come out as easily as the pads? They seem to be just hollow cylinders. I don't want to start tearing into things either. I just want to solve what I percieve to be an issue. I want my brakes back!!

In order to remove the pistons easily you have to separate the caliper halves. That would necessitate o/haul kits which aren't available from Ducati. You might find them at Yoyodyne. I wouldn't disassemble without replacing seals/o-rings.

You can remove the pads, push the pistons all the way back into the bore, remove the dust boots, and clean any dust or dirt that has accumulated from the bore.

My thinking is that bedding pads shouldn't cause the drag you're describing.

REDUC · September 02, 2009, 06:34:02 PM

Okay, thanks for the insight.

Howie · September 02, 2009, 08:11:41 PM

Before taking the calipers apart make sure the drag is excessive. Some drag is normal, particularly when the bike is on a stand. Can you compare yours to another similar bike?

REDUC · September 02, 2009, 09:11:17 PM

That's just it, my other bike has some drag, but not as much. And my dirtbike has none. Anyway, it's all back together now. I decided to just ride it and see. Hopefully everything goes okay and I don't eat shit and die.

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vibration while braking? (Not vibrating anymore, but now what?!!)