I'm thiking of going to a brembo master. Does anyone know the size of the BMW master cylider? I'm not sure yet which Brembo master would be the right one. They make a number of different options: 16x18 16x20 19x18 19x20 The first # is the bore size of the master the second # is the axis or pull distance of the lever. 16's are typically for bikes with a single disc vs. 19s which are for bikes with a dual disc but I'd rather know for sure. The axis or pull distance is personal preference "as that number increases it decreases the sensitivity and increases brake power." Lower numbers (x18) are said to give better feel to the brakes whereas bigger number (x20) more power to the pull. More info here: http://www.oppracing.com/pages/articles_brembo_master_cylinders/ Anyone know the volume or bore size of the BMW stock master cylinder? Is it a 16 or 19mm? Brembo makes some nifty new models like the 16RCS and 19RCS that are adjsutable: 16RCS will be a 16x18 or 16x20. The 19RCS can be a 19x18 or 19x20. Lets you adjust the feel.