Sachs made those 8 speed freewheels in the 90s for use with their New Success and Rival road groups. They were intended to be used with their hubs with 130 mm spacing. For mountain bikes, Sachs made casette hubs. In any event, the Sachs 8 speed threaded hubs had a beefy enough axle, but the freewheel side had a special spacer with a sleeve that acted as a reinforcement. I found the whole setup to be reliable, and still have one in use. The rear hub also had the flange spacing tweaked over the previous 126 mm old version to even the spoke tension a bit. Incidentally, there are also two versions of these freewheels….one spaced to Campagnolo spec. and the other to Shimano.