So I spooned on tires, rear pads, new rear bearings. I just for a joke wanted to spin the wheels and check out the brakes. On the center stand, I leaned the bike on front tire. Spun the rear with my hand and squeezed the front brake. Nothing. Put the bike on the rear and spun the front and hit the rear brake, the front tire stopped. I have ABS. Is this normal in a no run standing position? Or regardless, the front brake should have stopped the rear to when I spun it? No engine running, just standing/sitting, nothing on. I should have tried to search for this one, but I don't think I would have posed the right words to do a search for it. Still learning this bike.
There's plenty of good stuff on here about the braking system - but since you ask a question that is more to do with the behaviour, I'll put a brief summary in this post. David (Annas Dad) has posted his detailed information on each of the components - which is excellent. Other stuff you will find in the articles section.
When the bike is in the garage - stationary, on its centre stand - perhaps with a jack under the sump to raise the front wheel slightly:
1) Apply the front brake lever.
Both front brakes grab the two front disk rotors. The front wheel cannot be turned. If the front wheel isn't spinning, there is no effect on the rear brake. The front brake lever applies pressure to the two outer pistons of both front calipers equally.
2)Apply the rear brake pedal.
The rear pedal applies pressure directly to the rear caliper centre piston.
The rear pedal also applied pressure the front caliper centre pistons. The pressure is moderated by the delay valve, which allows the front left centre piston to be applied first. Increasing the pressure on the pedal allows the front right centre piston to be applied subsequently.
With the bike in the garage like this, the pressure from the rear pedal flows from the front left caliper, through the secondary master cylinder (which is part of the front left caliper bracket) and to the two outer pistons of the rear caliper.
The pressure on this line is moderated by the proportional control valve - this ensures that as the pressure applied from the rear brake pedal increases beyond a certain point, the pressure on the rear pads decreases. Yes really. This is necessary when the bike is moving due to the effect of the Secondary Master Cylinder (SMC). See 3 below.
3 The secondary master cylinder (SMC). When the bike is on the open road:
This is activated as a result of the front left caliper grabbing the disc rotor when the bike is moving. This will happen when the front brake lever is applied (activating the to front outer pistons), and also when the rear brake pedal is applied (activating the front left centre piston). In both cases, the SMC is activated, which acts like a second brake lever, and applies pressure to the rear two outer pistons, via the proportional control valve (PCV). The PCV ensure that under heavy braking, the effect of the SMC does not apply too much pressure to the rear brakes, which could result in a lockup on the rear wheel.
4 The ABS
Detects the presence of a lockup in either wheel separately, and momentarily reduces the pressure in the brake lines to the corresponding caliper, before then re-applying it. Repeatedly and very quickly.
General
If the piston in any of the 3 master cylinders is not able to return to its original state, then the pressure in the brake line cannot be relieved, and brakes drag. This problem rarely occurs in the front or rear master cylinder, but due to its position on the front wheel and the angle at which it is positioned, the SMC on the 1300 seems to be more inclined to this type of issue. Regular and thorough change of fluid and bleeding is required to prevent the build up of old fluid, sludge and crud. I do mine every year. It should not be left longer than 2 years, due to the rate at which brake fluid is able to absorb water.