Ridley

Helium SL

At around 1050 grams with the fork, the Ridley Helium SL rests squarely at the front of the market's low-weight frame offerings. And while most sub-800 gram frames are more akin to wet noodles, the Helium SL is responsive and bred for the racing in the mountains. Ridley made your choice easy.

So, if you're like us before our summer test ride of the Helium SL, you're wondering two things -- how is it so light, and what does that weight cost me in ride quality? We'll address these in order. Starting with the weight, the SL sees a 150 gram decrease from the last iteration of the Helium. This was achieved through the use of a more sophisticated carbon selection, this time utilizing a strategic placement of 60, 40, and 30 ton high-modulus carbon fiber. Before the SL, the Helium featured a predominately 30 ton carbon composition. Why is this important? Well, for a refresher, the 'ton' designation in '60 ton' refers to the carbon's ability to withstand 60 tons of pressure per square millimeter. So, basic logic tells us that a stronger carbon fiber requires less carbon to be used; as is the case with the SL. And on top of the carbon, Ridley bonded the carbon with a nano resin this time around. This further reduced weight, however, it also increased the strength of the construction.

Not surprisingly, Ridley wasn't done yet. To further reduce weight, Ridley constructed the front triangle of the SL with a monocoque design. This means that the entire front triangle (head tube, down tube, seat tube, and bottom bracket lug) is made in one piece. How does this save weight? Well, with the current SL system, the seatstays, chainstays, and dropouts are bonded to the existing triangle by applying resin and then over-wrapping the bonding points with more carbon fiber. With the SL, this application only occurs once, whereas you can imagine the added weight of repeating this process at every tube juncture of the frame. Furthermore, Ridley shaved grams by giving the SL a slightly smaller head tube dimension than the Helium, with a 1-1/8 x 1-1/4in tapered design instead of the Helium's 1-1/8 x 1-1/2in.

For further weight reduction, the SL has also received a new tube shape design. For some background, Ridley's design philosophy is that form needs to follow function. And to Ridley, nothing better demonstrates the harmony between function and form than that of shapes found in nature. Accordingly, the SL takes its design inspiration from the circle. Yes, the circle. Stop and think about it, and you'll realize that nothing provides a stronger construction with less mass than the circle. You've probably seen this on the Helium, only this year, the SL does away with the massive, oversized tubing. Now, the SL features rounded tubing emanating from the seat tube juncture, that 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 has been designed to intermix the two. The asymmetric, flat chainstays provide a stiff platform for power transfer to the rear wheel. Meanwhile, the ultra-thin seatstays create a vertically compliant ride quality without sacrificing rigidity.

And on the subject of rigidity, for all of the gram slashing going on, Ridley says that the SL is actually stiffer than the Helium. To be exact, Ridley's testing has concluded that the SL is 8% stiffer at the PF30 bottom bracket, 4% stiffer at the head tube, and the new fork design not only weighs 90 grams less, but it also has a 20% increased side stiffness. How does this translate to speed? In rudimentary terms, ride quality hinges what's called a stiffness-to-weight ratio, or specific modulus. And while the mathematics behind the determination of specific modulus are too complicated to explain here, it's not a complicated notion to grasp that a frame with low weight and higher stiffness will efficiently transfer power.

Ridley has also made the SL what it calls 'future ready.' This is a fancy way to say that its 100% internal cable routing has been designed to accommodate both electronic and mechanical shift systems. And in the case of the seatpost, the SL's rendition of the future sees a blast from the past. Now, the SL has done away with the Helium's old integrated seat mast to become the only frame in the Ridley quiver with a 27.2mm seatpost. This minimizes weight, makes it more user-friendly, and increases comfort through greater vertical compliance.

The Ridley Helium SL is available in the color Black/white/yellow and in five sizes from XX-Small to X-Large.