On my son's 86 Fuji, it came with a trashed wheelset...we threw in a set with a 9 speed Cassette Wheel....new chain, and it works just fine. A wider freewheel, and you do risk axle problems. Weight and harsh roads will tend to bend longer axels as you go to 7 or 8 speed freewheels. He rolls Friction, Suntour Sprint FD, Superbe RD (though it was Sprint at first) the RD handled it just fine.