I just replaced my chain on my bike because it was stretched and I want to avoid replacing the freewheel and chainrings. I just had the best idea.. I would take the stretched chain, clean it, and then take a section about 15 links long and make a keychain. So I did that and I reconnected it with the old pin (it's a keychain, not a drivechain... otherwise I would've used a powerlink). Here's the problem. Some of the links are stiff. What can I do to fix it?