I recently tried to change the chain on my road bike with a 7-speed sun tour freewheel and Dura Ace 7400 derailleur. I first tries a new SRAM 8 chain that is supposed to work with 7-speeds. Everything worked fine on the rack but chain slipped in almost all gears when applying any real pressure. I then tried a Shimano 7-speed Hyperglide chain and am having the same issue. Does anyone know of a chain that is compatible with Sun tour freewheels?