About The Zipp Service Course 120mm ±25° 31.8mm Blast Black Stem
The Zipp Service Course stem is a forged 6061 aluminum road stem in 120mm length with a ±25° angle, a 31.8mm bar clamp and a 1-1/8" steerer clamp.
The steep ±25° angle makes this the option for large bar-height changes, flipped up for a taller front end or down for a much lower one. Zipp's faceplate and body design aims for stiffness and easier installation, with a machined faceplate and stainless TORX hardware for accurate torque readings.
Who It's For
- Road riders who need a 120mm stem with a 31.8mm bar.
- Riders who need a large change in bar height, either up or down.
- Riders with a 35mm bar or a 1-1/4" or integrated steerer should look elsewhere.
What to Look For
- Bar clamp: 31.8mm.
- Steerer: 1-1/8" (28.6mm).
- Angle: ±25°. Steep angles also shorten effective reach when flipped up, so confirm your fit numbers.
Key Features
Forged 6061 aluminum. Alloy body built for strength and stiffness.
Machined faceplate. Machined and relieved faceplate on a 31.8mm bar clamp.
Steerer clamp. 1-1/8" (28.6mm) steerer clamp with 41mm stack height.
TORX hardware. Stainless steel bolts with TORX heads for precise torque readings and easy adjustment.
Finish. Bead-blast black with laser-etched graphics.
Rider Intent Summary
- Biggest strengths: Large bar-height adjustment range from a single stem and a durable forged body.
- Tradeoffs: Aluminum and stainless hardware are heavier than carbon and titanium options; 31.8mm bar and 1-1/8" steerer only.
- What makes it different: The ±25° angle covers position changes a standard ±6° stem cannot.
Victory's Take
At Victory Bicycle Studio we use a ±25° stem when a fit needs a big change in bar height, such as raising the front end on a bike with limited spacers; we confirm reach after the angle change, since steep angles shorten effective reach.
Specifications
- Brand: Zipp
- Model: Service Course
- Length: 120mm
- Angle: ±25°
- Bar clamp: 31.8mm
- Steerer: 1-1/8" (28.6mm)
- Stack height: 41mm
- Material: Forged 6061 aluminum
- Hardware: Stainless steel, TORX heads
- Color: Blast Black
- Weight: 150g (Zipp listed)
- Part number: 00.6518.031.007
What you get

Zipp Service Course 120mm ±25° 31.8mm Blast Black Stem
Frequently Asked Questions
Do you offer free shipping?
We do offer free shipping on non-bike orders over $100. We do not offer free shipping for bicycles unless it is a one time promotion. Generally, bike shipping will cost $150 and that covers just the shipping of the bike with no assembly. If you were to bring that bike to your local mechanic or bike store, you would pay them their assembly fee. If you choose our Professional Assembly option for $200, our service technicians would assemble the bike before shipping and then re-pack the bike safely for transit. When you receive the bike you would attach the front wheel, attach the seatpost/saddle, and raise the handlebars and clamp them. Those three items do have to be detached to minimize or eliminate the chance of damage in transit.
How much does shipping cost?
For orders of parts, accessories, apparel, etc. on orders under $100, shipping is a flat rate of $9.99. Regular bike shipping without assembly is $150, bike shipping with Professional Assembly is an additional $200 (so $350 in total which includes the $150 of regular shipping). Our White Glove Delivery option is $699 and that will cover the assembly of the bike and our White Glove Delivery partner delivering your dream bike to your front door, ready to ride!
How can I track my order?
When you place your online order, you will receive an instantaneous email update with your order number and order details, and shortly after, you will receive a follow up order email with the tracking number for your order. If you still need assistance with your order, feel free to email us at online@victorybicyclestudio.com and we will respond asap.