Guys-
You do NOT want SMOOTH brake drums! Drums get glazed, and lose their
gripability. You need the texture given by even just a clearing pass of the
brake drum cutter. Otherwise, you lose braking action due to the lack of
grip. Also, even though they look in good shape, drums will have a little
surface warp to them, and cutting trues them up properly, getting rid of
pedal vibration in the process caused by the drum being a little tighter
here, a little looser there, and the shoes going in and out with each
variance, which in turn plays the cylinders backwards, resulting in the M/C
giving that fun little pump to your foot. The warp comes from the heat build
up- which is un even usually due to the fact you brake and hit a different
section of the drum each time, and for different amounts of time- it is not
like you hit exactly the same spot, same duration each time.You create nice
hot spots. The heat does dissipate- part of the design- but you still get
this wear effect. Even if you're laying up the spare set- get them cut, then
coat them with a preservative, you can clean it off later, and have good
drums ready to go. So remember- Smooth brake drum- BAD, Properly finished
brake drum surface GOOD.
Scott
----- Original Message -----
From: <Popnglo@aol.com>
To: <Ryoung@navcomtech.com>; <triumphs@autox.team.net>
Sent: Saturday, February 14, 2004 7:36 AM
Subject: Re: TR3A 10"rear brakes wheel cylinders, etc.
> In a message dated 02/12/2004 7:52:01 PM Eastern Standard Time,
> Ryoung@navcomtech.com writes:
>
> > Unless there is some very definite reason the drums have to be turned,
I'd
> > leave them alone !
> >
> > At least until you find a new pair of 10" drums to have in reserve.
> > Otherwise, that's some _very_ expensive metal to be turning into chips
> > without a darn good reason ...
>
> Randall,
> You've got a point ... the brake drum surfaces are smooth, no pitting or
> scores. I had thought that it would be good to turn since they're out and
I have
> the time. I'll re-consider. I guess its not likely they are out of round
if
> there is no visible evidence. Any thoughts?
> Ed
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