Brembo Street Radial Calipers
The .484 and GP4-RX both use the 32/32 piston setup and are bridged across the top of body . These are both the same calipers ( nickle coated or black anodized ) , they are the top street Brembo caliper , but are really level with the radial P4 2 piece billet ( nickle or gold anodized ) ( not bridged over top of body ) with the offset piston size 30/34 (off the top of my head) , a caliper often used by racers in fact . All these calipers are available in various finishes , but are all billet , and are all 2 piece .
The other street calipers from Brembo , are the 1 piece cast items , currently fitted to many top line sport motorcycle . These caliper work good , I am not sure of the piston configuration , and represent very good value . The M4 Brembo is fitted to the '13+ Busa for example , and the M50 , which is I'm told fitted to the Ducati Panigale . The M50 maybe 100mm mounting option only .
But most of these calipers mentioned come in 2 mount sizes , 108mm ( Japanese ) and 100mm ( European ) . Best to search out a caliper you like and see if it lists either your choice of bike or the compatible mounting spacing your bike requires . Also ,as example , the pads available for say the 108mm GP4-RX , is the same pad for the 100mm GP4-RX . The M4 cast monobloc also uses the same pad range as those of the billet mentioned .
Now every Brembo beyond the mentioned calipers are from then on the race items , in monobloc , in full billet aluminum , starting out from the first trick GP4-RR monobloc caliper to 3 or 4 further up scale and scary $ choices .
The street variants are a great choice , but must have a corresponding master cylinder for full effect .