Genuine Front Master Cylinder Body Assembly suitable for 750cc & 850cc Norton Commando models (Not MK3).
Bore Size: 13mm
OEM: 06-1939/13
Note: Piston bore has been reduced from the original size of 5/8” to 13mm. You now get excellent pressure on the brake pads. So much so that you can lock up the front wheel at any speed should you so wish.