Smaller brake master cylinder

[scribbles]

Has anyone got and experience/ feedback from fitting a smaller master cylinder fort the front brake? I change the calliper on my r100gs for an 1100 four pot a while ago and didn't notice much, if any improvement. There did seem to be less movement on the lever though and thought it would be worth have some mechanical advantage by changing to a smaller master cylinder. I think its a 13mm one on the r100gs and as far as i can tell the smallest is 12mm. Quite expensive just to try it though so it would be great to hear from anyone who might have already tried this. b

 

[Timolgra]

It'll be a 2 pot caliper surely?

I'd try something like a 2nd hand master cylinder from something like a KTM 690 which operates a similar caliper as I presume your still on one caliper and disc?

 

[Box’a’bits]

Did you do any servicing work on the 4 pot before you mounted it, ie popped out the pistons, cleaned the bore, popped in new seals. More likely to be a sticking piston.

 

[scribbles]

I didn't check it but it seems to work fine, a tiny bit better than the two pot original but only just. the lever has no travel though and feels like the cylinder ratio is wrong for the calliper. it isn't progressive. Is it possible to put an aftermarket brake and master cylinder on without loosing the throttle controls? Im not at my bike at the moment but i seem to remember its all one unit. Has no one tried changing to the 12mm cylinder?

 

[Kenny]

A properly bled OE fitment master cylinder, doesn't give virtually any play either !

 

[(RIP) Arkwright]

This might help you!

http://www.vintagebrake.com/mastercylinder.htm

I found a 13mm too spongy, and a 15mm too wooden so I made a 14mm (which you can't get for a GSPD)

The HE 320mm disc is the biggest improvement you can make in my humble opinion!

 

[litelfun]

jeh you need to go up a grade try 14mm i use 15 16 and 18mm but I am runing a 6 and 8 piston calipers on my bickes