I'm surprised you have retained the Indy SL. I realise that there is a purist ideal to recreate a bike to as it left the factory state, but on the other hand why not respect the Kona vision of seeing their bikes as upgrade platforms? I'll bet if you asked the designer whether you should stick with the Indy or go to a Bomber or a blue SID, he would wonder why you were even asking.
In this case, I believe the argument is stronger than usual, as with hindsight the decision to spec an Indy for 97 was pretty clearly a mistake. The decision would no doubt have been taken sometime in 95 and based on Rockshox's assurances of what the (new for 97) Indy would be like, rather than on having tested one. It was only after it came out that it gradually dawned on everyone what a bad and hideously over-priced fork it was. You could get them on massive discounts for years afterwards. After this experience, Kona abandoned Rockshox in favour of Marzocchi on their high end bikes for 98.
I believe that the 97 Explosif is probably the stiffest and heaviest of the three Columbus Max Explosifs. It was the only one that had all Columbus tubes, including the stays as well as the front triangle. The stays are visibly chunkier, especially than the very slender seat stay on the 96 Explosif. I imagine this must have added a couple of ounces, but no doubt made for a better and faster bike overall. I think steel designers were gradually upping the stiffness (and weight, but without admitting it) at this time, because they saw a need to compete with the attributes that were making aluminium more popular with the market.
