I had a set of Pro-Links in my Reaction-X. They were early models without the circlip on the shoulder bolt. They kept backing out no matter what I did. I bought the replacement shoulder bolt kit with the circlips from Todd and installed them. They backed out and knocked the circlip off after about 4 flights. I screwed them back in and wrapped some saftety wire around the groove for the circlip then twisted it real tight. No more shoulder bolts backing out. Haven't had the spring problem yet.

Bob