2012 Specialized Shiv

Specialized overhaul’s their timed race bike to create a machine specifically for triathletes.

The original Specialized Shiv was created as a time trial bike and triathletes rigged it up to meet their purposes using add-ons and spacers. The all-new 2012 Shiv is designed specifically for triathletes. Its fit dimensions match the needs of many more triathletes and it offers a wide range of adjustment that allow the bike to match the rider’s fit preferences without using a mountain of awkward spacers. In addition to the tri-specific fit, the 2012 Shiv hides an internal bladder to reduce the need for external hydration products that can add drag to a bike.

PHOTOS: 2012 Specialized Shiv

Fit

The most important changes to the new Shiv are frame geometry and fit adjustability. The 2011 Shiv might have been an aerodynamic success, but it created fit problems for many triathletes. It could only accommodate a single aerobar, the headtube didn’t lengthen as the bike got larger and the basebar could not be raised. As Specialized engineer Luc Callahan put it, “The Shiv was positioned really aggressively, and honestly it didn’t work for everybody.”

Instead of designing the frame geometry for ProTour cyclists that race short time trials, the new Shiv’s geometry designed specifically for triathletes. All five sizes have a relatively tall stack height compared to the reach value and these dimensions scale linearly from the X-Small frame size to the X-Large.

The stack and reach values for the five frame sizes (all with 700c wheels) are:
X-Small: Stack 495mm, reach 365mm
Small: Stack 515mm, reach 385mm
Medium: Stack 540mm, reach 405mm
Large: Stack 565mm, reach 425mm
X-Large: Stack 590mm, reach 445mm

The 2012 Shiv is designed to easily accommodate widely ranging positions without big compromises to aerodynamic performance, stability or stiffness. The previous Shiv relied on spacers to lift the elbow pads, and those spacers have been replaced partly by the taller headtube. In addition to the taller frame designed for positions more commonly ridden by triathletes, it comes with an extremely adjustable aerobar and a traditional steerer tube that can be clamped either to a standard stem or a proprietary aero-shaped stem, allowing the bike to use any aerobar. This aero stem can be positioned directly on top of the head tube or it can be lifted 25mm or 50mm. The stem has two clamp positions that alter its reach. The shorter orientation creates a 60mm stem and the longer position lengthens it to 90mm.

All these changes sum to create a bike that can accommodate a wide range of positions commonly ridden by triathletes.

Aerodynamics

Continuing with the theme of creating a bike specifically for triathletes, Specialized ignored the UCI rules governing frame tube shape. Those rules state that a frame’s tubes cannot be more than three times deeper than their width. This limits aerodynamic performance and is the reason other brands, such as Trek, are using truncated airfoil tube shapes. Passing those rules aside gives Specialized the freedom to create the Shiv’s shockingly deep headtube and downtube. The headtube is 4.1 times deeper than it is wide (4.1:1 ratio). The downtube has a 3.9:1 ratio, the fork blades have a 3.4:1 ratio and even the seatpost violates UCI regulation.

Specialized road product manager and aerodynamicist Mark Cote explained that the aspect ratios were tuned for the specific wind conditions faced by different portions of the bike. He says that the rear of the bike experiences wind at a narrower yaw angle at a lower speed than the front of the bike because of interference created by the bike and rider, therefore these parts of the bike need different tube shapes. In addition to the radically deep tubes, Specialized added a fairing behind the steerer stack extending above the toptube. Many aerodynamicists say a gap behind the steer stack creates substantial drag and this fairing, called the Control Tower, helps minimize that drag. Cote says the difference is not massive, but is measurable in the wind tunnel.

Instead of using an integrated front brake, Specialized opted for an external caliper. Cote says the extra drag created by the exposed housing is tiny and he believes the ability to easily adjust the brake offsets that aerodynamic sacrifice.

Hydration

The Shiv has a Camelbak-style bladder hidden in the headtube and downtube called the Fuelselage. The bladder slides into the frame through the top tube directly behind the stem. It’s sealed with a rubber stopper that can be removed to refill the bladder on the go. The hose pops out of the frame out behind the stem and lays onto the aerobar extensions. Specialized cleverly placed a magnet in the valve and a matching magnet in a strap that can be positioned anywhere on the bike to hold the hose and it from flopping around. Two valves are available, one is a bite valve and the second is an upturned opening without any seal. The bladder holds a little more than 20 ounces of fluid, depending on frame size, and can be removed from the bike to be cleaned.

Mark Cote declares “making sure all the things a triathlete needs has a home on the bike” was one of the design team’s biggest goals when planning the 2012 Shiv. In addition to the Fuelselage, the Shiv has a seat tube water bottle boss to hold standard bottle cage. Cote says a water bottle on the downtube has a substantial aerodynamic penalty but a bottle on the seat tube has a miniscule impact, so he decided to include only this single mount.

Rasmus Henning has a one-of-a-kind storage pod that sits between the aerobar extensions and mounts his Garmin computer head unit. Although these aren’t yet available to the public, it sounds like Specialized is considering a similar storage option for non-fluid nutrition needs. The saddle can, of course, accommodate a behind-the-saddle hydration system.

More Bikes

In addition to the S-Works Shiv, Specialized has a complete line of bikes with the identical frame shape, stretching down to the $3,000 Shiv Comp. This version comes with a mix of entry-level components and the aluminum version of Specialized’s new aerobar design. This bar has the same range of fit adjustment as the carbon version, but has a slightly different basebar shape. Specialized is also offering mid priced versions with higher-level spec kits. The S-Works frame will be offered both as a complete bike and as a module, which includes the frame, brakes, Fuelselage, aerobars, crank and chainrings. The S-Works versions will be ready to go in October and the other models will come in the following months.

Written by Aaron Hersh. Follow him @triathletetech.
All photos by Nils Nilsen. Follow him @triathletephoto.