Walked past a hotel in Westfield Stratford yesterday and police outside then saw that it was london hq for the games. Few competitor's swanning around..
Quick Google and it seems they are using the velodrome in the Olympic park as building one in Brum wasn't cost effective
I think the short notice with which Brum took over hosting when Durban had to drop out also contributed to this. Only two new venues and one renovated.