P08 v P09

can someone please tell me the difference between a Brembo P08 caliper,and a Brembo P09. I believe my recently purchased 1982 1000 sp has the P09 on the rear,this has been butchered quite badly in the past…Anyhoo,I can’t seem to find a P09,but there is a P08 availiable,and it looks the same in a photo??

Later models all have the P8 both ends, though they did have a different splitter valve.

If you can find a P09 it gives far superior braking, but a P08 will fit and do the job.

Thanks chap’s…that makes the search a little easier

I have a spare rear P8 but it is in need of refurbishment, seized / snapped bleed nipples, rusty pistons no pads etc. It came in a box of bits from a clearance sale. You are welcome to it for not a lot.Where abouts are you?

sounds very similar to my P09. Have a clever friend who is going to take a look at my 9,in a few days…plus another member has offered some parts,thanks Don…oh Kings Lynn is where i’m at

Let me know if you want the one I have, nice excuse for a ride out over to kings Lynn

P09 has bigger area pads. Spada’s have this on the back; also, their rear connector block (manifold?) for the pipes (behind LH frame tube) incorporates a pressure control valve. This valve closes off the route to rear caliper (the P09) for high fluid pressure.

The idea is, for modest pedal pressure you get (supposedly) 50/50% braking force front/back (on the basis front disc is bigger diameter than rear, hence larger pads on the smaller rear disc to balance it out ~ in theory

If you press the pedal harder it goes 60 - 70% front 30 - 40% back, because the valve has cut off the rear caliper fluid supply. I.e. rear caliper pressure doesn’t increase. Or not by much. In theory.

How do I know all this? Had to rebuild a manifold once to replace said valve, so had to find out what the blinking flip the flipping thing does.