Precision and Performance
The ultimate in performance and technology
Your stem has to resist flexing during sprints and accelerations, clamp securely to the fork and handlebar, and support your weight over significant impacts. It’s a difficult job, but the Service Course® stem is still able to combine strength, stiffness and reliability at a weight of 130 grams (100 mm length).
The Service Course has high-strength, 3D-forged construction, 7075 series aluminum and stainless steel bolts to deliver an exceptional strength-to-weight ratio while allowing for smooth lines to complement the aesthetics of modern frames.
We make our Service Course stems in seven lengths (70 mm to 130 mm in 10 mm increments) and two angles ( /- 6 degrees and /- 17 degrees) to meet any rider’s fitting needs.
Zipp chooses Torx®-head bolts for its stems and aero bars - why? It’s simply a better bolt:
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 that 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, M5, 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 a 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.
$76 / €68
Bike Radar 05/10/2011 May 2011