The way i understand it the astra pump will increase pressure as the demand increases and is built into the pump, there are a couple of ways to wire them up as to the pump starting up, i have two pumps here ear marked for my ute and factory power steering box. Im just going to run them as is and hope the box will handle it, first pump i picked up for $60 so you can find them cheap. Also apparently they can draw a bit of power so a good alternator will be needed.
My son also has a ktm 520 exc, fast bike for a 17yo that weighs about 80kg.