disc brake question

[BAHNZY]

I'm sure that i'll be shot down but i'll way in with my 2 cents worth.
IF.... It was only the master cylinder there would be 3 fifths of stuff all performace gain. The master cylinder does nothing more than generate the pressure and the amount of pressure is modulated via the bore size and the ratio of the lever acting on the piston. Any perceived performance gain from a late model master would be negated by a single piston small pad caliper that was fitted to the Pre85 bikes.

IF... You fitted both the master cylinder and caliper then it would be a whole different ball game and it would be a substantial performance gain.

Where a real modern technology performance gain can be had from the old school Pre85 disc brake system is to ditch the crappy 26 year old (or thereabouts) hydraulic hose and fit a current spec stainless braided brake line. You would think the brake system has been replaced.

And for what's its worth, given that Kawasaki's (and others) were fitted with disc brakes then essentially you can fit a disc brake to a Pre85 bike as long as the specification is no greater than the Pre85 unit. The big question is wether the drum brakes of  Pre85 vintage are better than the first disc brake offerings. To help you, look to what happened to KTM during the 83 to 86 year models.

[Maico31]

Thats a fair enough comment Bahnsy.

[STW996]

I totally agree with you and Bahnsy John.

[asasin]

I run a honda frunt end on my RM 250 D 83 and a Kawasaki master cylinder all pre 85. The trick with disc brakes is to get them matched for what you prefer to have hapen , ie sudden and locking or progressive to the fist full.My bike stops on a dime but being a old school type rider I just jump on them so what I have works for me , and yes they are truckloads better than my matched and set up twin leading unit was.

[Gerard De Ruyter (Twistandshout)]

i was wondering myself about where exactly you get the extra braking power from on modern bikes (seeing the basic design's stayed the same for donks).  an engineer mate said its in the master/lever unit, where they build in higer leverage ratios, which would make sense (ie, for each mm of lever travel you get one and half mm of oil travel or something like that).  result is one finger action. 

other improvements i guess are less flexy lines, more brake pad contact area, better pad compounds, bigger discs etc.