All the brake in the world is of no use if the tires won't grip the
pavement. While I understand the need to upgrade from front drum to discs,
why is a big brake kit desireable up front, when the stock discs will out
brake any tire that will fit on a Midget? Also, in a dual circuit system,
don't the rear brakes apply first, and then the fronts when progressively
more pressure is applied? The rear brakes then do most of the slowing, and
the fronts do the final stopping, and as braking forces act, weight
transfers from the rear to the front. It also seems desireable that the
rear brakes would lock slightly before the fronts, because if the fronts
lock, you can't steer.
Or do I have this all wrong?
----- Original Message -----
From <Daniel1312 at aol.com>
To: <PhastPhill@aol.com>; <billyzoom@billyzoom.com>; <rbc43@starband.net>;
<ladaniels@sbcglobal.net>
Cc: <spridgets@autox.team.net>
Sent: Wednesday, April 13, 2005 3:50 PM
Subject: Re: New Addition
> Well, the figures I have don't support my statement as much as I would
> like.
> From memory on standard brakes in good condition on a 69 Sprite they must
> have been close to 50/50 because before I fitted the rear bias valve the
> rears
> had a slight tendency to lock before the front on dry tarmac.
>
> At MOT time, UK equivalent to your inspection, there is brake dyno test
> that
> reads out in lbs the braking torque generated at each wheel.
>
> The brake torque figues for a standard brakes and bias valve were 200lbs
> best
> front figure and worst 180lbs. Rear brakes were 50lbs rear on the bias!!
> The
> parking brake would produce 170 best and 150 worst.
>
> SO, my Sprite produced 200 front and 170 rear which with weight bias UNDER
> BRAKING gives the rear too much brake but not by much. You do the math
> but durr
> 75% looks close...
>
> With bigger disks and calipers (Spitfire/MGB) up front and 8" drums I get
> 345lbs worst and 395lbs best which is about double the standard best. I
> don't
> have as reliable figures for the rear brake and parking rear brake
> operation
> because I think the tester could see the brakes were in super-car league
> even
> without taking into account the weight of the car (approx 1631 lbs) but I
> have
> recording of 230 best and 186 worst. I have some other rear figures which
> are
> suspect indicating 385lb and 395lb.
>
> However, the car is due an MOT within the month so I'll try and get a note
> of
> the figures.
>
> Regards
>
> Daniel
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