To use the secondary spring or not, that is the question?
On the viking and wolverine RSPEC we sell a sheave and a clutch kit with a secondary spring, more times than not the Green spring is used. The spring will be used by most people but some it might affect top speed, some it will not tire size, elevation and weight control this more than anything. The stiffer spring helps more on the low end and through what is called shift phase. So a simple answer is some will like it some will not. Depending on the kit you are buying it is optional or part of it but just because it is part of it does not mean you must use it. For some the lighter roller weights will be enough for them to get the rpm up and help with overall performance without affecting top speed. Basically what I am telling you, some will want it, some will not and you will not know which you are until you try it and for $30 either way, you will not be out much if you decide it is not for you. As I like to tell my Polaris customers, you can't rock crawl and dune with the same clutch set up, just does not work that way.