Looked on SA's site,they have a 120mm OLD 8spd;you might be able to squeeze that in without frame mods. Otherwise,you'll be looking at getting the frame modded or a custom built rear triangle. As bhkyte said though,the 5 and 8spd SA's don't have as good a rep as their 3spds. Also note that 1st gear on the 8 is direct drive(the rest of the gears step up from there),so you'd need to set your gearing up accordingly.