Originally Posted by SEAcyclist100

Duo,

I just finished converting from a 5-speed freewheel to a 7-speed freewheel on an old Sekai 2500. What I ended up doing was just replacing the 5-speed with the 7-speed and then just troubleshooting from there. All I ended up doing was adding a washer on either side of the axle to keep the wheel symmetric about the center of the bike while allowing for sufficient clearance between the chain and the inner side of the right rear dropout when the chain is on the smallest sprocket. This method will also make you avoid having to try to redish the wheel (moving the center of the rim relative to the axle) which can be costly or impossible depending on how robust your rim design is. However, just adding washers symmetrically seems to work just fine for me after 150 mi for me.