Originally Posted by
LordBass
I recently read up on this as I'm consider a 6->7 speed freewheel conversion for my 12-speeds. As usual, there's a good description at the Harris Cyclery site. I highly recommend a visit there.
As I recall, a Shimano 7-speed freewheel is $20. You'll also want the Park 2-notch freewheel tool. And something to brace it in to spin the freewheel off the hub.
Shimano still makes a 14x28 7-speed freewheel but that's about the only current production. You may be able to find other configurations as NOS items if you make the rounds of bike shops. Nashbar sells a wider variety of 7-speed freewheels made by Sun Race. These are ok but the Shimano is better.
When removing a Sun Tour freewheel, particularly a 2-notch one, clamp the remover tool firmly in place with the qr skewer or the axle nut and use a BIG wrench or clamp the remover in a vise and use the wheel itself as the turning lever. Start loosening the qr or nut AS SOON AS the freewheel begins to break loose.