The Pinarello Grevil is based around Toray T700 carbon, same as what’s found on the Pinarello Prince Disk road bike. All frames are capable of fitting anywhere between a 700 x 25c road tire to a 27.5 x 2.1” mtb tire. This is thanks largely to a dropped chainstay, akin to what OPEN and 3T has done with their gravel bikes to ensure the bike has short 420mm chainstays like a road bike. However, Pinarello found that using a dropped chainstay substantially changes energy transfer from the wheel to the saddle, and so they designed what they’re calling their Twin Arms technology. In short, because the drive side chainstay is dropped, the drive side seatstay ought to be dropped as well to ensure the rear of the bike responds to stress similarly. Small details, but enough that make a Pinarello holistically unique from the competition.