Date:         Fri, 30 Dec 2005 18:24:13 -0800
Reply-To:     Bruce Nadig <motorbruce@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Bruce Nadig <motorbruce@HOTMAIL.COM>
Subject:      Re: warped SA rotors...
Comments: To: mrpolak@yahoo.com
Content-Type: text/plain; format=flowed

Chris,

I had already read the article.

Sorry about this. Rotors do warp. I've been in the car and motorcycle
industry for about 10 years. I've seen my fair share of truly warped rotors.
Yes, some develop hot spots, which have the net effect of heat treating
themselves into harder metal. Yes, many times the pads or the wheel torques
are to blame. But rotors can and will warp - both car and motorcycle.

Cheers,
Bruce
motorbruce@hotmail.com

>From: "Chris S." <mrpolak@yahoo.com>
>To: Bruce Nadig <motorbruce@HOTMAIL.COM>, vanagon@GERRY.VANAGON.COM
>Subject: Re: warped SA rotors...
>Date: Fri, 30 Dec 2005 18:03:34 -0800 (PST)
>
>Sure... but... according to this expert article, rotors do not
>"warp" - they merely accumulate brake material unevenly or
>develop hard spots made of cementite.  Very small amounts of
>said substances translate into vibrations when braking.
>
>I highly recommend reading it:
>
>http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml
>
>
>--- Bruce Nadig <motorbruce@HOTMAIL.COM> wrote:
>
> > No experience with the SA Big Brakes here, but here is one
> > other interesting
> > note.
> >
> > The times that big time race teams have the most brake rotor
> > problems is
> > during testing. Typically a car will go out, run some hot
> > laps, and return
> > to the pit for a debrief. The car will then go out for a few
> > more laps, and
> > once again return to the pits. This can be repeated over and
> > over all day.
> >
> > What the brake discs are seeing is massive heat cycling. The
> > hot laps get
> > the discs glowing hot in many cases, and then the cars come
> > into the pits
> > where there is no cooling air running over them as they sit.
> > The cycle is
> > repeated again and again. So, what the teams see is repeated
> > massive heat
> > cycling on a large scale with periods of stagnant non-cooling
> > air during pit
> > stops.
> >
> > Repeated heavy heat cycling can warp rotors. In real world
> > conditions this
> > can mean driving over numerous passes, building heat, and then
> > having
> > insufficient time to cool properly.
> >
>
>
>
>
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