Date: Thu, 11 Jun 1998 18:36:48 EDT
From: John Magyar
In a message dated 98-06-11 15:56:23 EDT, you write:
>For better braking, sleeve master cylinder to 14mm or even 12mm is
the
>best mod, providing a leverage improvement of 28%.
>
>A point to watch when replacing the calliper is the piston size -
the
>stock Norton ones are 44.5mm dia, and the readily available Lockheed
and
>Grimeca are 41mm (Triumph) size. The reduction in area between these
is
>equivalent to a reduction in leverage of 15%. The 44.5 dia Lockheed
is
>part CP3697. I fitted a Hyde fork brace after sleeving the master
>cylinder - to cure the rapid sideways oscillation of the front wheel
>under heavy braking. Later I put a 12 inch conversion on, which was
>fiddly to fit, looks good but was not a dramatic further improvement.
Spot on Allen. I started with a Stock 44.5mm Lockheed, EBC pads and a Migura 11mm master cylinder. This is setup is very aggressive and provided awesome stopping power but really allowed the rider to push the outer limits of the stock calliper/rotor combination. In racing, under very hard braking, one would getting reasonably predictable stopping performance ... once, then the next several turns would have varying degrees of mushy brakes. I believe this was a symptom of boiling brake fluid; I was tempted to try some titanium shim stock as a heat shield (low thermal conductivity) between the pad and the piston, but I felt that this would manifest as another problem (i.e. torching the pad compound thoroughly).
Given the limited pad compounds available for the stock calliper, I opted for a Norvil 12 inch (period) rotor, Lockheed 41mm racing calliper, and the Migura 11mm master cylinder. What I lost in hydraulic advantage I gained in mechanical advantage (12 inch Norvil vs. a 10.7 inch stock rotor diameter) so at least on paper it was a wash. Two of the primary extras with this set up are increased swept area and more rotor mass to absorb (sink) heat energy. This proved out rather nicely this last weekend at Road America in Elkhart Lake, Wisconsin (US). No longer did I have to predict my brake performance after every turn.
>Does anyone who has experienced clutch slip know a cure?? I have
>segmented the clutch pushrod, and added a garter seal to it. Also
used
>Barnett plates, which don't slip but wear out. Now on the 'new' type
>Norton bronze, the ones with narrow sharp edged grooves - and these
are
>slipping after 2000 miles...
The Barnett is my only advice here. The other plates you have used or are contemplating should give adequate service under moderate road use but any oil on the plates and severe loads will likely give you problems.
Regards,
John Magyar