GT's I-Drive system is nowhere to be seen, with a more conventional four-bar layout (plus an idler pulley) used instead.

Wyn's old ride, pictured to the right, is a single-pivot, 210mm-travel machine that employed GT's floating bottom bracket and dog bone link I-Drive system. GT has used different versions of their I-Drive design on all of their high-end full-suspension mountain bikes over the years... until now.



Best I can tell, Wyn's new bike ditches I-Drive for a more conventional four-bar, Horst Link system with the twist of an idler pulley at the main pivot.



Why an idler? Well, the main pivot is quite high and, without an idler to route the chain up and over it, the suspension would firm up considerably under drivetrain loads.

Wyn's old Fury was a single pivot bike but new one uses all the pivots.

Routing the chain up and around the main pivot allows the suspension action to be largely isolated from pedaling forces.

You can test in private all you want, but nothing simulates racing like, er, racing. Past years have seen the New Zealand National series be the ideal place for racers to test their fresh bikes against the clock before the World Cup season kicks off later in the year, and 2018 is no different. In fact, last time this year, Pinkbike photographer Cameron Mackenzie spotted a revised version of the Fury that used an altered shock angle to add in more progression. This was so Wyn and Brook could use a coil-sprung Fox shock on more courses.'Eagle Eye Cam' is at it again, it seems, as he's sniped photos of yet another GT prototype under Wyn Masters. This one, however, is an entirely new beast compared to the Fury - everything is different. We have precisely zero information about the unnamed carbon fiber bike, and Wyn was understandably doing his best to avoid Cam's questions, but the upside is that leaves us to speculate. My favorite hobby.Many shorter travel bikes use this to their advantage to feel efficient under power (otherwise known as anti-squat), but downhill bikes live in a very different world where traction and suspension action trumps everything else.Also notable is the frame material - the stout looking front is a carbon job, while the rear end is aluminum. You might remember that the first generation Fury was carbon front to back, while the second gen was aluminum. It looks like GT is going back to carbon for their downhill bike, however.The rear-end could also only be aluminum on Wyn's bike while they tinker with different suspension geometries, with the production version possibly being a full-carbon frame. That's just a guess, though.We're debating whether or not it's rolling on 29'' wheels; it's hard to tell in these photos. The larger wheel size would, in itself, makes sense, but the tall lower headset cup hints that the bike might be able to run more than one wheel size, so we might see GT's racers on both options in 2018. That doesn't mean the production version will sport the same feature, of course.There's no word on suspension travel, but I wouldn't be surprised to learn that it's somewhere between 180mm and 200mm when on big wheels.What else can you make out from the photos of Wyn's prototype DH bike?