Anyone heard of "A Plus" or "A+" brand rotors?

[Mark R]

I've got customer's DOA S4 in my driveway today I need to debug, so a quick
note:
All of the modern Audis are fairly heavy cars with adequate brakes for
normal stops.  Not great brakes, but adequate.  If you do a lot of rapid
aggressive stopping, the thermal mass is completely inadequate.  "Warping"
symptoms of the rotors on a street driven vehicle are quite common and
generally caused by brake pad deposits (material transfer) and/or actual
"warping" due to uneven brake force distribution (single piston calipers not
sliding freely).  Each of these conditions leads to hardened areas of the
rotor and pulsations (especially when hot).

The thermal properties of rotor material are fairly critical for optimum
performance.  (Assuming the machining and vane design is equal in quality.)

There are a lot of imported (Chinese) rotors which are branded under local
distributor or store names.  They're inexpensive, but definitely not
optimized.  Higher quality rotors generally have better mechanical (steel)
properties, better machining, mill balancing, and often have coatings on the
hub area to help protect from corrosion (stuck wheels, rust causing
unbalancing, etc.).
For a street driven, fairly inexpensive rotor, I often recommend Brembo
plain finish rotors.  Good quality, good mechanical properties (even if
imported from Mexico), and not a very high price.

Proper installation is also critical.  Here's a tip that belongs in every
brake FAQ and not many even know about this:
How many people or shops open a new rotor, put it on, and douse it with
brake cleaner?  You're lucky if a shop even uses the brake cleaner!  Modern
cutting fluids are all water-based.  Brake cleaner is good to remove the
greasy fingerprints and other oily contamination, but not a water-soluble
cutting fluid.  New rotors should be first washed in soap and water (dish
soap).  Still use the brake cleaner just before putting the car into service
to clean away any contaminants such as hand oil, brake fluid, caliper
lubricant, etc.

Lubricate the caliper guide pins with a high temperature caliper grease.  If
worn, replace the pins and boots.  Inexpensive, and this is what allows both
pads to share the work on a single piston caliper.

Lastly, proper break-in of the rotor and pads is critical to avoid any
initial pad material transfer and long life.

There's more to braking systems than just price.  Maybe it's my engineering
background, but to me material composition is critical.  It's not much more
money to go with quality components.  Over the service life you'll benefit
from smoother braking and improved performance.  Heck, if it saves you ONE
minor accident, they've paid for themselves.

So much for a short note.  Good luck!

Mark Rosenkrantz (Stoptech brake distributor who also sells more mundane
braking components).


On 12/8/06, Brett Dikeman <quattro at frank.mercea.net> wrote:
>
>
> On Dec 8, 2006, at 1:22 PM, Bart Oleksy wrote:
>
> > My '98 A6 QW needs new pads & rotors on the front. I've been quoted
> > $450
> > (CAD) installed, but found an eBay seller offering these rotors
> > made by
> > A Plus/A+ for quite a bit less.
> >
> > Do I need to run away from this screaming, or would it be worth
> > considering?
>
> It's probably chinese steel or worse.  I'd take whatever a ebay
> seller tells you with a huge grain of salt :-)  If you want to know a
> ton about brake rotors and stuff like steel grades and who makes what
> and how well... Mark Rosenkrantz is the perfect guy to ask. I cc'd
> him to raise it up on his radar.
>
> For reasonably priced OEM stuff, try talking to Clair Parts Express
> in MA, or at least see what a Worldpac dealer like SJM will charge,
> and go from there.
>
> Brett
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