buy a new wheel with the fancy 11 speed hub.
Unless you are stripping all the 11 speed stuff of one bike to build the other.. Dont bother...
9 was when road and mtb stuff had cross over potential.. better touring bike use.
Plenty of 9 speed stuff sold, so though its not the latest trend, bike shops still can get repair , service parts..
....
Last edited by fietsbob; 01-13-18 at 12:26 PM.