Adjustable, aero, elegant
What does that mean for on-the-bike performance? Pro triathlete Jordan Rapp put the Vuka Stealth on his bike and just six days later won the Leadman Epic 250 Triathlon, with its grueling 223 km cycling leg. “I never really noticed the bar, which is probably the highest compliment I can think of,” Rapp said. “I basically forgot it was there, which was awesome.”
The Vuka Stealth integrates the stem, basebar and mounting hardware into a single streamlined aero system. The base bar uses a truncated airfoil shape that maximizes aerodynamic efficiency while maintaining the UCI’s 3:1 aspect ratio requirement. The basebar’s Rapid Routing cable exits are positioned for easy installation of brake cables.
The Vuka Stealth is available in three separate stem lengths – Short, Medium or Long. You pick one. Each size also includes a stem-length spacer to increase stem length by an additional 10mm. That gives a total of 50mm of stem-length variation. The effective stem angle results in no rise, or what would traditionally be referred to as a -17° stem.
To achieve an optimal fit, the bar offers scores of additional adjustments to its “stack” (vertical measurements) and “reach” (horizontal measurements) as well as options for pad width and position plus extension width and length.
The Vuka Stealth is crafted from unidirectional carbon fiber and uses titanium and aluminum hardware. It is made with the industry standard 22.2 mm extension clamp diameter for maximum versatility, making it compatible with Zipp’s Vuka Extensions (Race, Straight, Ski-tip or Race Vuka Shift styles) as well as most extensions on the market. Extensions are sold separately.
The Medium Vuka Stealth with Zipp Vuka Race carbon extensions weighs 820 grams. Compatible with all current drive-train systems and all plug-in style brake levers.
Note: The Vuka Stealth ships with integrated stem and basebar, Vuka Stealth extension clamp & armrest clamp, Vuka Stealth risers (two each of 10 mm, 25 mm and 50 mm risers), Vuka armrest pads and Vuka armrest. Also included are a T25 L wrench, carbon paste and a 1/4 turn Zipp Quickview mount with an integrated and proprietary mounting interface.
The Vuka Stealth is available in Short, Medium or Long stem lengths. Use this Stem Selector worksheet to help determine which stem length is right for achieving your fit coordinates on a specific frame.
Vuka Stealth Frame Compatibility
Some aero frames with integrated cockpits are incompatible with the Vuka Stealth aero system. This Vuka Stealth Frame Compatibility sheet lists frames with known issues.
Zipp chooses Torx®-head bolts for its stems and aero bars - why? It’s simply a better bolt:
- Won’t easily strip.
- give more accurate torque readers.
- Are durable.
It comes down to the way the tool head interacts with the bolt. Common hex tools tend to strip the bolt head if the bolt is over torqued. This is especially true with lightweight bolts. Zipp wanted to be able to use a lightweight bolt with reliable performance. Bolts on stems and aero bars are critical to safety – having a reliable bolt is crucial.
The Torx® head is more robust than hex-head bolts and will not easily strip. Torx® fasteners also were designed for use with a torque-limiting wrench (torque wrench), which is needed to achieve the precise torque reading for proper installation.
We chose a bolt size – T25 – that was best suited for our stems. The standard Torx tool head for an M5 bolt is a T25, although sometimes a T20 or T27 is used. The T25 is becoming a go-to bolt in the bicycle industry. It’s been used on disc brakes for years and also is in use on chainring bolts, derailleurs and shifters. What’s more, the T25 tool is common in bike shops or hardware stores and is readily available alone or in multi-tool sets. For your convenience, Zipp includes a T25 wrench with all stems and aero bars.
- Size: 40(Center-to-Center)
- Integrated stem: Short, Medium or Long
- Stem-length spacer adds 10mm to any of those sizes
- Steerer tube diameter: 1-1/8"
- Weight: 820g (Medium stem length with Zipp Vuka Race carbon extensions).
- Clip Compatible Integrated mounting hardware
- Extension clamp width: 22.2mm
- Extension shape Extensions sold separately