Re: Brake Dust Covers (Kleen Wheels)

["Pete Read" <pete.read@xxxxxxxxxx>]

Kleen Wheels always seem to generate a lively discussion.
I've posted my experience with them to the bmw-digest 
several times, but I've been able to restrain myself
for over two years -- I must be feeling weak today.

My opinion remains that they work fine as long as one
uses common sense.  Here's what I posted back in Nov '96.

...old bmw-digest post...
Subject: Re: Brake Dust Covers (Kleen Wheels)

For some reason I'm compelled to keep responding to this 
question of brake dust covers.  Maybe I'm just trying to 
remain on Steve Bernstein's "thank list" <g>.     
 
I have been using the Kleen Wheel brand successfully for a 
number of years on my wife's station wagon, my former 
'87 535i, and my present '88 M5. They have saved me a lot 
of wheel cleaning time.  Note that they are a convenience, 
time-saving item only, with a performance tradeoff. 
 

Tradeoffs
- --------- 
Like many products with positive benefits, brake dust covers 
are a tradeoff.  Their purpose, which they perform very 
well, is to reduce brake dust build-up on the wheels.  The 
tradeoff is reduced cooling air to the brakes because they 
work by restricting the flow of brake-dust-filled cooling 
air through the wheels (small directional air flow vents in 
covers). 
 

Why front wheels have more dust 
- -------------------------------
Front brakes work harder than the rears because of forward 
weight transfer during braking, creating more pad wear and 
related dust.  Extra front brake dust is also partly from 
greater air flow compared to the rear wheels.  Front wheels 
have significant airflow passing under the car, and then out 
through the front wheel openings.  Much of this outboard 
moving air passes through the wheel, cooling the brakes.  
The more airflow, the more brake dust on the outside of the 
front wheels. 
 
Brake dust covers restrict the outward flow of air through 
the wheel.  This reduces both the brake dust and cooling air 
to the brakes. 
 

Recommendation
- --------------
>From reading advertisements, Kleen wheels are TUV approved.  
TUV approval or not, some common sense needs to be applied.   
If you drive moderately and don't want to clean your wheels 
as often, they may be worth a try.  If you drive hard and 
stress your brakes, don't even consider them. 
 
I drive very moderately on the street, so brake dust covers 
work for me.  However, driving schools are another story and 
illustrate the point about different brake cooling 
requirements.  

At the track, my M5 needs as much brake cooling as possible.  
The dust covers are removed and brake ducts, in place of my fog 
lights, are routed directly to the inside of the rotors through 
the opening behind the calipers. 
 
A final bit of advice about removing brake dust covers.  Sometimes 
they stick to the wheel mounting surface.  Just use a thin 
bladed tool, such as a putty knife, to separate the two 
surfaces. 
 
  Pete Read 
  '88 M5
  Arlington, VA

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