The Sturmey XRD is a drum brake hub for a thread-on freewheel (7 speed).

The only cassette hub currently made for drum brake is the Shimano Nexave with roller brake splines. Given the poor cold weather performance and heavy weight of the Shimano roller brake, I wouldn't suggest it, however.

BTW, if you're avoiding bare canti posts, you can pick up a fork made specifically for drum brakes here:http://cgi.ebay.com/700c-Roller-Brak...2em118Q2el1247