converted.............

theres talk here about mechanical bias AND hydraulic bias.

the bar does the mechanical bias, the brake bias valve adjusts the balance hydraulically..

both do what Converted mentioned.

from memory the hydraulic method is sh ite. it introduces something called hysteresis into the braking system. I'm not fully oiled on this...it has something to do with a hydraulic delay occuring when the brake pedal is released?????????????(or it takes a split second longer for the brakes to activate)

Why do you need both???????? I'm sure the store preson wants you to buy both, but since they both do the same thing, and one has a huge disadvantage...you may be better of with only the bar.