I subscribe to Russ' advanced data which lets you overlay any number of shaft profiles on the same graph. We're not allowed to post the numbers or detailed graphs but I can confirm that in terms of EI curves, the KBS Tour 105s and TGI 90 have nearly identical EI bend profiles and bend profile signatures. In general, the Tour and TGI shafts have very similar EI profiles just as KBS claims. If you're use to the Tour or $-Taper shafts then the TGI line should be a good fit. You just have to experiment to find the right shaft weight. I was a long time KBS Tour 120 user and then played the $-Taper 120 for a few years. I switched from those to the TGI 80 about a year ago. Even though the weight is significantly lower, it only took me about a week to get use to them. For me the feel and performance is identical to the KBS steel shafts.