I have a non O ring regina chain running ironman 13/50 sprockets. The chain and sprockets are still in spec. The rear has some wear and the front is basically brand new. I pulled my chain off to clean it, so I soaked it in kerosene for a bit. I dried it and was going through each link and the master link hinge is very stiff. I tried working it back and forth and it is a little better but still really stiff. I have it soaking in some penetrating oil right now. Any other tips that might help?