Warped disks... AGAIN - Ducati.ms

Kitesurfer · Jan 26th, 2012, 8:07 pm

I know this has been discussed before, as I was one of the participants in the discussion. I just thought I'd start a new thread to bring it to the foreground again.

I have had my front disks/pads replaced twice (that's right, I am onto my third set) since new and I can feel the shimmy starting yet again. The first replacement was at 9,000km, the second at 18,000km, and guess what: I'm on about 25,500 and it's happening again right on time. By the time I'm up to 27,000, it will be shaking its head off I'm sure.

So, anyone else noticed it happening with such regularity? Why every 9,000km? (it actually begins sooner than 9,000 but it's only very slight and hard for the ham-fisted tech to reproduce).

I've had many other bikes for far more kms than this one (my last was 70,000km) and I've NEVER had a recurring disk warping problem before. In fact I've never had it once, let alone 3 or 4 times in the first couple of years!

I will keep getting them replaced under warranty, but what happens in 9 months when the warranty is over? Is this just a bad batch of disks that my replacements keep getting taken from? Or is there some design flaw? Could there be something else (e.g. incorrect or mismatched assembly onto the carriers or something)?

Before you all chime in and say I must be riding it wrong, remember this isn't my first first bike

Thanks in advance for your thoughts!

Rob

w0mb2t · Jan 26th, 2012, 8:14 pm

over 30k and no problem .....

if it isn't a set of circumstances unique to you then perhaps horrible bad luck/coincidence ????

joeducati · Jan 26th, 2012, 8:18 pm

Makes no sense to me! I've owned lots of bikes and never replaced discs on a street bike, only my race bikes. Are the pads wearing pre-maturely? Maybe they are installed incorrectly and are dragging on the dics to build up heat to warp rotors? I'm reaching here, but have no other ideas.

HumboldtDuc · Jan 26th, 2012, 8:21 pm

Hey,
I frequent another forum as well and we recently saw something similar that was resulting from dirty pistons on the front calipers. The pistons on the calipers were really gummed up and werent retracting as they should, causing the brakes to drag, generating and retaining a LOT of excess heat in the pads. This was a bike used for street and track, so it saw plenty of heat, maybe more than your application. The owner complained of similar issues with brake pad life and rotor warpage on a bike where it is not a common problem. Cleaning the pistons, replacing the pads and rotors, and a fresh dose of fluid eliminated the problem completely. I have heard that an improperly adjusted fork (twisted in the triples) can also cause the brakes to drag, but I have yet to see that be the case.

Kitesurfer · Jan 26th, 2012, 8:35 pm

Quote:

Originally Posted by HumboldtDuc

...I have heard that an improperly adjusted fork (twisted in the triples) can also cause the brakes to drag, but I have yet to see that be the case.

Funny you should say that: I was looking down along the forks whilst riding the other day, and wondering if there was anything about the assembly of the front end that might contribute...

I do sometimes check the disks for heat when I get off the bike, and have never noticed any excessive high temps.

One punter said that a disk lock might cause this, but that sounds a bit unlikely as they are very small/light and I have used them on other bikes with no issue. Ducati Performace even sells disk locks, so it's hard to believe they could be an issue.

w0mb2t · Jan 26th, 2012, 9:06 pm

Quote:

Originally Posted by Kitesurfer

One punter said that a disk lock might cause this, but that sounds a bit unlikely .

ahh yes , of course. i once had my front rotor warp with a disk lock .... never forgot again to remove the damn thing

Kitesurfer · Jan 26th, 2012, 9:08 pm

Quote:

Originally Posted by w0mb2t

ahh yes , of course. i once had my front rotor warp with a disk lock .... never forgot again to remove the damn thing

What's that strange noise?

**Chuckracer** · Jan 26th, 2012, 9:40 pm

I took down a whole line of bikes in front of a club one night because of those damn things...

Check in the Sport Touring section...there's plenty of warped discs threads. Search under "Shudder" or "Shuddering". The consensus is that it's the uneven depositing of pad material on the discs causing the pulsing feeling.
I don't know if your discs were measured for runout or not, but maybe all they need is a good cleaning?

My KTM 950 Supermoto was starting to do this same thing - a few HARD stops from 100mph or so fixed it, but it's probably best to use a scothbrite pad.

Kitesurfer · Jan 26th, 2012, 10:14 pm

Quote:

Originally Posted by Chuckracer

Check in the Sport Touring section...there's plenty of warped discs threads. Search under "Shudder" or "Shuddering".

I was one of the participants in some of those threads the last time it happened.

Quote:

Originally Posted by Chuckracer

...I don't know if your discs were measured for runout or not...

Yes, runout was measured and found excessive both times before, and the way this feels, I expect to find runout again. Will measure and let you know.

Cheers.

w0mb2t · Jan 26th, 2012, 11:50 pm

Quote:

Originally Posted by Chuckracer

I took down a whole line of bikes in front of a club one night because of those damn things...

.

pictures or it didnt happen