Hi Norm, BB and prd,
It was indeed rusted solid prior to removal, and it did work fine at that point. I think the brake disc flexes slightly when you apply the brake, so if it is seized close enough to the fixed pad, then it still works OK.
I would like to replace the key but it is 1/4" by 3/16" which seems to be a less common size.
I have another possible method for tightening up the key. It is snug in the keyway of the brake disc - just loose in the key seat on the shaft. So I'm inclined to use a retaining compound like Loctite 660 which I have, just to hold the key to the shaft. That would tighten it up but wouldn't prevent the disc sliding on top of the key.
I rarely use the brake, it's mostly just a safety device should the drive belt or chain break. So a small amount of play may not matter that much. I just don't want it loose and rattling around too much as I drive along.
On the other hand, since pad wear will be minimal and I think the disc flexes, locking it in place with the ability to loosen the grub screw and adjust when needed might be fine too!
Cheers,
RLP
