The Helium SLX Ultegra Di2 Complete Road Bike from Ridley checks off all of the traits we want in a race bike that will be ridden hard in the high mountains. Its rock solid stiffness channels every last watt of pedaling effort to the rear wheel and gives it the ability to telepathically track down a tire blistering descent with authority, while its atom weight simply floats up relentless mountain passes like, well, a balloon that's filled with its namesake. Unlike that balloon, this machine is made for the long haul and will have you searching for riding routes taking you to ever-higher elevations. Ridley packs its typical meticulous and durable carbon layup with a race-ready geometry that'll have you ready to attack any time the road turns up. This particular build gets a peloton proven set of Fulcrum Racing 5 wheels and Shimano's venerable Ultegra Di2 groupset for crisp and precise shifting time after time. You'll find a climb-happy personality from this elegant ride, starting with a blend of 60, 40, and 30-ton high modulus carbon fiber. The result is a World Tour-worthy frame that efficiently transfers power while shaving about 30g of claimed weight compared to the previous SL. The front end sees a slightly different curvature at the tube junctions, a small change that Ridley claims boost stiffness by 15% and translates into even snappier, more responsive handling when diving into switchbacks or pushing out of the final corner. Simply put, it's a bike that prizes stiffness to weight and feels great every time you stamp on the pedals. As with the SL, the SLX features rounded tubing emanating from the seat tube juncture, which slowly becomes box-shaped as it approaches the head tube and bottom bracket junctures. As Ridley puts it, this system creates a clean transition from stiffness to comfort. Supporting this ideology, the rear triangle blends the two shapes. The asymmetric, flat chainstays provide a stiff platform for power transfer to the rear wheel, while...