New rear brake drum for 650 from 47-70, Triumph 500 47-74. Its time to change your brake drums when your drum gets badly scored. THIS BRAKE DRUM HAS A 43 TOOTH SPROCKET CASTED IN. YES, IT CAN HELP YOUR TOP END. THE LOWER THE REAR SPROCKET COUNT THE MORE TOP END YOU HAVE. IT IS AN 8 BOLT PATTERN AT THE HUB . WE HAVE EVERYTHING YOU NEED TO FIX UP THAT REAR WHEEL. IF YOU DON'T SEE IT IN OUR STORE YOU CAN CALL US AND WE CAN HELP YOU