The original superstar frameset in the Ridley line up was the Excalibur. It balanced lightness, stiffness, durability, and beauty -- in other words it melded nearly every variable that matters when you're considering a new frameset. It makes logical sense, then, that Ridley chose to expand upon the Excalibur platform with the design of the Helium. Like the Excalibur, the Helium is built in a monocoque design with oversized, round tubes. Its tubing diameters are equally beefy for optimum flex-resistance, and it has the same enormous-diameter tubing junctures at the headtube/down tube and down tube/BB, as well as the oversized integrated headset with a 1.5" lower bearing.
But unlike the Excalibur, the Helium features an integrated seatmast design akin to the super-aero Ridley Noah. We will cut down the carbon fiber seat tube of the frame based on your saddle-to-BB measurement. You'll use a custom Ridley seat clamp that seamlessly mates to the seat tube and offers three different positions to modify your effective seat angle. The use of this integrated seat tube/seatpost maximizes the stiffness of the Helium and it offers added frameset stiffness when you're putting the bike under serious in-the-saddle pressure, and of course it looks like a million bucks.
Even though the Helium is made with an integrated seat tube/seatpost, it weighs less than the Excalibur at 900 grams thanks to the fact it uses a superior grade of carbon fiber. The Helium uses 30-ton carbon with areas of 40-ton and 50-ton reinforcements (in comparison to the 24-ton carbon used on the Excalibur.) By using higher-grade carbon, Ridley can literally use less carbon in the production process, netting a lower weight bike. The Helium also utilizes full carbon dropouts and doesn't use any aluminum in the head tube bearing races to reduce weight further. And when you factor in the detail that you need to use a conventional seatpost on an Excalibur, but you don't on a Helium -- the real net difference is weight is well over a half-pound in savings with the Helium.
You may be new to integrated seatmasts. For that matter, you may be new to sub-1000g framesets. Take heart in this fact: The Helium was the bike used by the entire Silence-Lotto team in the devastating cobbled classics like the Tour of Flanders. In other words, the durability of the Helium is second-to-none. Just because it might look exotic, it sacrifices nothing in terms of longevity. And in proof of how dynamic the Helium really is, it's the bike used by Cadel Evans as he single-handedly tried to fight off the Team CSC/SaxoBank armada in the high mountains of the 2008 Tour de France. And the tradition carried on into the 2009 season, where Team Katusha captain Fillipo Pozzato drilled his Helium for nearly the entirety of the spring classics campaign.
The Helium comes in 5 sizes from Extra Small to Extra Large. Given its compact geometry, we strongly suggest that you focus on the virtual top tube length as you make a determination of the proper size. Please provide us with your BB-Saddle Rail height in the "Comments" section of our order form so we can properly cut down the seat tube for delivery. The Helium comes with a matching Ridley 4ZA monocoque full carbon fiber fork and a proprietary FSA integrated headset. It requires an English bottom bracket, and a 34.9mm front derailleur. It has a 5-year warranty from manufacturing defect.
One final note on sizing: On all sizes the top of the seat tube is 235mm above the center of the top tube, not including seat mounting hardware. The standard Helium seat clamp has 18mm in height adjustment, and comes with a 1mm micro-spacer for small adustments. Ridley also offers an aftermarket clamp that provides 40mm of height adjustment.