Originally Posted by
AUPedla
BR-6403 brake pads are still available.
And it won't last forever, I bet! I actually found a shop on eBay recently selling
5-pairs for $30/shipped. I already have a 3 new pairs in a box in the shop, but went ahead and grabbed 2 x 5pk from that place and sealed up on arrival to keep fresh..
Shimano lists the following as fitting 64xx calipers, but most of these have similar shapes w/o the plastic grey outer ... which may be transferrable, I can't remember if the outer shell pops off or not.
BR-3300 / 4400
BR-1050 / 1055
BR-A250 / A350 / A450 / A550
BR-A410 / A416