Originally Posted by
Canker
or just buy a sunrace 12 speed cassette that uses the standard style freehub body
That's a really good point but that will limit the OP to a 11t smallest cog, rather than the new 10-51t put out by Shimano.
I was thinking of doing the same thing because I have the Sunrace 12 speed 11-50t but going to a 10-51t would allow me to switch from a 30t to a 28t chainwheel, resulting in a little higher top gear and my low gear would be pretty damn low (good for climbing because I wouldn't be in my largest cog for as long, if ever).
Mind you, I have reallly big 29x3.0 tires so takes a lot of gear reduction to kick those guys over.