Not sure of the stock ratio, but the bore is 16mm, hence the big improvements from the radials' 19mm.
The 4 pads give more feel and bite due to them having more leading edges from the 4 pads vs.. the older 2 pads.
When you need to swap pads again, try the Bendix MF compounds. They are very good. Leave HH for dead. Comparable, maybe a little better than SBK3's but cheaper. They really are very good
