shot rotors perhaps..

[Ledz558]

I had new brake pads, as well as new sprockets and chain put on my bike. So when I ride now I get a tremendous loud sound  like a foghorn in the front which vibrates up through my handlebars and my back wheels make an uneven swirling sound. I was thinking well maybe the rotors are shot. Since on the front, I have two different ones. The reason being someone ran over my bike while parked which caused the front right one to get bent. Try riding on a bent rotor down the 101 to find a used one fast, though I did.

So should I just buy new rotors all around to get rid of these sounds and the uneven movement of the bike. This bike feels like its uneven and actually moves back and forth to the unevenness when I slow down. As long as I drove this bike for 8 years, I never had this type of thing happen where I felt like the bike was doing this pulling thing. It ran fine without a sound before this work was done. . How long do brake rotors last?  I currently have 20k on them. Or did the mechanic not do the brake pads, chain, sprocket etc right.

Thanks! 

[Curmudgeon]

Good grief! It's pretty scary that the shop would give you the bike back in that condition without taking a test ride first!

What are you riding, BTW?

Just a guess but it appears that something is misaligned. If you are mechanically proficient, loosen the front axle and pinch bolts and vigorously pump the suspension up and down a few times, tighten the axle, then the pinch bolts and see if that makes any difference.

From the accident I suppose it's possible that a fork leg was bent. A good shop can put a dial indicator on the rotors and see whether they have any run out.

Since you say the bike wasn't doing this prior to the work, I'd suspect faulty reassembly and go from there. Others here may be more helpful once they know what you are riding.

Good Luck!

When you have a chance, do the intro thing so that we know a bit more about you. http://www.ducatimonsterforum.org/index.php?topic=111.0

[Ddan]

Since everything was fine before the work was done it's likely that the problem is something they did, rotors don't just suddenly bend.  Was this done at a reputable shop?  If it was, bring it back and see if they'll check their work.  If you want to do it yourself I'd start with checking the alignment of the rear wheel, cleaning the rotors with scotchbrite and brake cleaner and then properly bed the new pads.

http://www.ducatimonsterforum.org/index.php?topic=34924.msg611108#msg611108

[Slide Panda]

How long do brake rotors last?  I currently have 20k on them. Or did the mechanic not do the brake pads, chain, sprocket etc right.

There's no fixed life for stuff like brakes, pads, chains etc. For rotors it depends on the sort of pads you have, the rotor material, your riding style/habits etc etc etc.

Most will have info stamped on them regarding the minimum thickness. YOu put a micrometer on them in a few spots and if they are below that min, then they are done.

But, it sounds like you've got other issues that need to ber checked first. The the fellas noted, the alignment needs to be checked and it's possible you original rotor and that used one are not true/warped/bent as well.

[Howie]

Your first step is to return to the shop that did the work.  It seems all was good until they replaced your brakes.  I will take a guess what is going on though.  My guess is the rotors are dished (worn in a concave shape) so only the outside edges of the pad are making contact.  If so, the shop should have suggested new rotors.  Another possibility is contaminated pads.  Oh, too many other possibilities.  As Sad Panda said, micrometer measurements in a few places will tell the story.  Thinner in the middle than the outer edges, dished. 

[Ledz558]

Hmmm where do I begin, so much great info here..
The bike was in a crash in 07, this at the time had the replaced rotor on it. I believe the front forks might have got damaged because this latest mechanic who by the way said the rotors were okay, said I had a leak in the front left fork.  Howie when you say contaminated pads? how could this be if their brand new.

I did take the bike back and told him about the loud noise, the uneven sound, he got on the bike right away and took it out. He came back and said he heard no sound, nor uneven sound.

So guys today as I rode to work, the front sound is still there, but the uneven sound in the back is not as intense. It made me think that the pads were wearing to the rotor.  Is this possible?
Now the front axle is smashed on the left thread from the 07 crash. Since it has never been taken apart since then it might have an effect on the alignment. And maybe this guy didn't check the alignment.
He is the kind of person that would micro the rotors he's very particular, and I asked if I needed new to rotors he said no.


I have a 04 620 capirex by the way with a crack in the gauge. My speedo and tac don't work anymore.

Thanks for your input I really appreciate it.  

[Howie]

Contamination could come from greasy fingers or brake fluid when bleeding.  Getting better is a good sign.  Yes, pads do wear into the rotor.  If the pads overheat in the process squeal and sub standard braking performance may persist.  It does sound like your dealer is working with you.

[zooom]

Now the front axle is smashed on the left thread from the 07 crash. Since it has never been taken apart since then it might have an effect on the alignment. And maybe this guy didn't check the alignment.

you never had had new tires mounted in the 4 years since the accident?

[Slide Panda]

Howie when you say contaminated pads? how could this be if their brand new.

Ever left a greasy hand print on something you didn't intend to after doing some work on the bike? Simple as figer grubby with oil/grease/brake fluid grabbing the pad.

I'm thinking Howies on track with rotors that are out of shape some how.

[Ledz558]

Zooom I used to get tires put on at the same time religiously.  In 07 when I was in Hell A, I couldn't ride for awhile. I was busted up with a broken arm. I relocated to a colder climate in 08, rode it up to 10 and then the bike sat for awhile because the climate killed the battery. It survived the worst winter cold, mind you stored in a dry place and was covered.

So beginning this year I saved up a lot to fix it. The back tire was replaced in 10, but the front one still has good tread on it. My mechanic really isn't a fly by night guy who takes advantage and these I've had in the past. He's a specialist from Germany, worked here in town at a place that dealt with euro cars. He knows the in's and out's of BMW bikes, ducati's, truimphs, and also he services all the cops bikes here. He's the only good choice I have here in town or I could take it to a 20 year old kid who would just want to joy ride it at this other shop.  Which would yo choose..   Zooom I would assume that he did check the alignment, he's really picky, in fact he found a leak in a gas tube inside my tank, and fixed it in a minute. For years this caused gas to leak out from the bottom of the bike when I filled the tank and no one  in Hell A could fix it. His shop Howie is immaculate you can eat off the floor, I couldn't imagine this guy getting grease on the pads.

The place I live is small so I really don't have many experienced mechanics here like I did in Hell A. Believe me I was gonna buy used rotors on ebay and he flipped out in his german accent..

"Do not do zhat, zhis is terrible! only new brake parts always! Don't ever put used brake rotors on za bike"

So hey I do trust this guy.  My rotors are 249 a piece... in his parts book. Well..he was upset that I brought my own chain which was a cheapie off ebay a classic china model. He said it is not held together solid and is dangerous so he ordered me a better oring chain. He also got me a new left hand  turn switch from Duc in italy because mine doesn't work it got smashed in the 07 crash.

Right now I don't have the money to put on the better chain or turn signal,. I do need a new dash, mine doesn't work and I have a huge crack in the gauge. So I can't tell how fast I'm going... which makes riding always looking for cops in your mirrors.

Other than that I love this bike, its my second monster, my first was a 02 750.  Its my best friend.

And bottom line after all this...I would imagine the rotors are just bent from the crash. So it looks like for my birthday in January I know what I'm getting.

[ducatiz]

I would not bother with a cheap chain but the cheap rotors coming out of China are very good.  Poke around and see my review of them.