I just ordered a pair of RW 8131s in size 5.5D and going by the size chart on the RW site a 5.5 is around 23.5cm but when I asked a seller on ebay to send me the length of the sole and insole he came back with 11" which is 28cm....
Bay Area resident, kickin' around college. Joined to become more informed and knowledgeable, as well as possibly using the classifieds as a (better?) alternative to craigslist.