Sturmey-Archer 3 speed stuck Cog
I have an old and weather beaten English Hercules with a Sturmey-Archer 3 speed hub. There is a cog on it, but no lock ring (I don't know whether this is normal or not). The cog is on the hub body pretty solidly and I'd like to remove it. When the cog is freewheeled backward the only visible part that moves is the hub body that it's threaded on to. Without managling this little bit of threading is there a way to loosen and remove the cog?
Someone else may have more info, but I know that the newer sturmey-archer hubs don't use threading, but rather a ring clip (small metal hoop with a cut in it) that snaps into a little groove next to the cog and locks it into place. To remove the cog you need to find the break in that ring and force the ring open and up off the hub. The cog then slides off the hub body.
for some reason hercules bikes continued using the threaded drivers after sturmey-archer phased them out..
probably they got a good deal on 10 million spare threaded drivers from s-a...
you must remove the driver assembly from the hub in order to hold it adequately to remove the cog.
sheldon brown addresses the issue here:
if you don't think you want to use your threaded driver and cog i would trade you for the exact replacement but later and more standardized splined style