Actually, the only reason I went from 3 stages of Vector clutch kits to just a single stage, was due to demand. I sold very few of the Stage 1 and Stage 2 kits. It all comes down to how much inventory you have on the shelf and varying combinations make for more inventory = more investment, it made sense for us to nix the Stage 1 kit (helix and primary spring back in the day) and the Stage 2 kit (primary spring and weights only) and now we only offer a full kit (primary spring, weights, and helix). The performance gain from clutching, is actually quite impressive, especially when paired with a intake mod, header, and Power Commander on the fuel injected Vector models. They will run with an Apex to 100 mph when setup with that combination. The basic fact is that 90% of Vector riders aren't huge performance enthusiasts, so we don't spend a ton of dollars on product development for that particular sled, but the products we have work very very well.
