If we had one critique of Wilier's GTR Team frame, it's that the lower grade carbon used in its construction bumps the claimed weight up above the 1,100g mark. That's pretty petty, we know, especially when the half endurancehalf race geometry makes it such a pure joy to ride. Wilier addresses this petty concern with the GTR SL Ultegra Complete Road Bike, which combines a full Shimano Ultegra drivetrain even the crankset, which is often where specs take a miserly turn with a lightweight frame that comes within 200g of the Zero. 7 super bike. If we were stuck on a desert island with a 50 mile tarmac circuit that included a crosswind riddled coastal stretch, a long, sweeping descent, and a CAT 1 climb, this may be the bike we'd want with us. We're aware that there are some potential pitfalls anytime we designate a frame's geometry as endurance. It conjures images of upright, boardwalk cruising or weekend charity sportives punctuated with frequent stops for trail mix and under ripe banana halves in volunteer staffed rest areas. The GTR SL is happy to dabble in those passive pastimes, but its take on endurance geometry actually falls between the comfort focused machines produced by most manufacturers and the Euro slammed race bikes populating criteriums the world over. The GTR geometry manages to feel at home in everything from circuit races to hill climbs to coffee shop loops. It may not be the capital B Best at any one discipline, but few of the endurance frames we've ridden over the past several years do so well in so many applications. When compared with the GTR Team, the GTR SL frame at the bike's heart loses about 200g of claimed weight by bumping the Mitsubishi carbon up from 4630t to a truly high modulus 6040t mix. Those impressive numbers let Wilier hit its targets for stiffness to weight ratio with much less material. There is a corresponding increase in price, but given the weight savings we think it's worth it to spring for the SL. In a s..