Rotors

[heatherp]

Hi all.

My front rotors are pulsing and I'm noticing it even more now Brad (mechanic) pointed it out to me after 50k service.

I don't know the first thing about rotors so time to study up. And seems like another opportunity to Bling! 

Would appreciate your experiences/opinions. And pointers to relevant threads.

Bike is 2005 1000s DS and I live in Oz.


Thanks fellow Monsterers. 

[booger]

First try scrubbing the rotors with Scotchbrite pads and alcohol/carb cleaner, then sand the pads down a bit on a flat surface. If that doesn't help then go for the new rotors. Might save a lot of money.

[junior varsity]

If you feel a lot of pulsing, its from warped rotors.

Material Choices:
a. Stainless have great longevity and are good even if you ride infrequently.
b. Iron has better feel and stopping power but will look rusty if sitting for awhile.
c. CMC and the Carbon Rotors are the most blingtastic, lightest, etc

You want a nice lightweight carrier to save rotational, unsprung weight.

There are lots of choices available.

Wave rotors help clear debris/moisture removal and cooling, also look neato.

Floating: Three or so options are available:
1. Full Floating - rotor is free to move laterally from carrier a little bit which helps prevent warping and provides only contact directly perpendicular to pads, the way you want it. Makes a bit of noise. Floating Buttons may need replaced for wear after several years
2. Semi Floating / Damped - Somewhere in between rigid and full floating. Longer Carrier Life, not as noisy, not as wonderful as Fully Floating, but not all the 'disadvantages'
3. Rigid - no noise. no ability to expand or move with heat. buttons don't really wear out.

Tons of brands are out there:
Brembo, ISR, Braketech, Braking, Beringer, Spiegler, ABM, ALTH, PVM, Galfer, MotoMaster, Discacciatti, etc etc etc. Its a wear component so there's a lot of options out there. Most cost between $300 and $450 per rotor. (USD) Brembo isn't the "best", but they make damn good rotors. Don't get a steel carrier, that's 1980's tech. lightweight alu carriers are the way to go now.

[Cider]

I thought modern stainless was as good as iron?   I was under the impression that most WSBK and GP rain rotors were stainless.

I warped my Brembos and bought a set of Braking rotors.  They work fine, and aren't terribly expensive compared to other aftermarket rotors.  IIRC, they are lighter than the OEM rotors as well.  Unfortunately, I changed other parts of the brake system at the same time, so I can't give a good comparison.

[junior varsity]

I think most modern stainless is 'almost' as good as iron, but i don't have the appropriate machinery to give you hard numbers on the differences in longevity and stopping power. The fancy ceramics and the like are the top notch.

[Howie]

Cleaning the brake rotors may work, but before doing anything put a micrometer to them.  At 50K miles they ate likely below minimum thickness.  If so, they should be replaced.  If they are not worn beyond specs, also make sure the buttons are clean.  If the blade cannot move on the buttons it will feel like a warped rotor.

[Moronic]

Have you had this problem for a while or has it just started suddenly?

By about 6k miles the front brake on my 07 S4Rs was pulsing quite badly. My mechanic (not the dealer) said a warped front rotor was the only reason he could think of. My dealer checked with the importer and supplied different grade pads under warranty, suggesting I try these first. Problem disappeared over the next few hundred miles, and a few thousand later you'd never know there'd been an issue. 

I'm not sure whether the shop cleaned the rotors before fitting the new pads.

[Ddan]

This might be helpful:

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml#

And maybe this:

http://www.stoptech.com/tech_info/wp_bedintheory.shtml

[junior varsity]

Dan,

Those are well written, really cool articles.

[heatherp]

Thanks for the info so far.  Makes for interesting reading and I now know lots more about brakes. But I'm still not sure what I should be doing.

The problem is long standing (about 9 months) and the bike has done 50k kilometres (not miles) we're metric down here in Oz land. 

[Ddan]

First thing to do is what Howie said, measure the rotors.  The minimum spec will be stamped on the rotor.  If they are in spec, check that the rotor can move on the carrier.  It's likely that the buttons have some crud built up in them and they can be a pregnant dog to clean.  Third step, assuming  the first two checks are good, is to clean the rotor really well.  Use an abrasive pad with brake cleaner.  Get that done then remove the face layer from the pad, again with an abrasive and brake cleaner.  You should be able to get a new-looking surface on the pads.  If you still have the original pads, get rid of them and start fresh.  The OEM pads are OK but there are much better options.  I don't know what you have available in OZ but I've had really good luck with DP pads.  http://ducatimonsterforum.org/index.php?topic=18933.0  He can get you set up. Make sure to bed them in  as described in the links above.

 If after you measure the rotors you decide you need new ones, I've found some very good deals on used ones from Ebay.  The stock rotors with good pads will give you all the braking you'll ever need, but  there are other options, too.  The snowflake rotors that came stock on some Superbikes are beefier and lighter, the aftermarket has some blingy options if your interested and  iron rotors are great. 

[heatherp]

All well and good if you have the appropriate tools and know how.  So do you guys do this sort of stuff yourselves, at home or do you get a workshop to do it?

[Ddan]

All well and good if you have the appropriate tools and know how.  So do you guys do this sort of stuff yourselves, at home or do you get a workshop to do it?

I do it my self. I'd rather buy tools and I'm 4 hrs from the nearest shop I trust.  This is all relatively straight-forward stuff that can be done with a few tools.

[printman]

This might be helpful:

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml#

And maybe this:

http://www.stoptech.com/tech_info/wp_bedintheory.shtml

Great article  pain in the a.. but worth it