Although this sounds like a good idea, don't you think it takes away the theme of ancient fire lighting methods.
Stick to using a bowdrill as is without modernizing it, your bound to get more satifaction from making fire by friction than:
'Oh, I made fire by friction with the help of sprucing up my bearing block with a bearing, maybe next time I'll use packing grease to make it a little more slicker and maybe I'll dip the tinder bundle in a bit of petrol to help it catch from the coal!"
IMHO some things should stay the way they originally are.