Run your favorite 31.8mm clamping diameter handlebar on a bike with Knock Block with the Rhythm Comp 31.8. It adds Knock Block compatibility to a durable stem with multiple lengths to let you fine-tune the fit to your ride. Get 31.8mm handlebar compatibility with your Knock Block system;Also compatible with standard headsets and spacers;Knock Block system protects frame from impacts by fork and handlebars by eliminating over-rotation of bars;Available in a wide range of sizes for today's mountain rider;See Service Parts for other Knock Block parts;

On today’s road bikes, silver stands out amid the sea of stealthy black color schemes. This time-honored color is available on the Zipp Service Course stem. Since the introduction of our line of Service Course and Service Course SL components, we’ve had amazing success with our pro-level athletes in all disciplines. While the successes have reinforced our design decisions, we have also drawn from their feedback. We not only learned how and why athletes make their equipment choices, but how our manufacturing methods and materials affect product performance. With new knowledge as well as new engineering methods, we are proud to introduce our completely redesigned line of Service Course and Service Course SL stems. - Class-leading stiffness-to-weight ratio - More options for a better fit - New faceplate and geometry for greater stiffness and easier installation - Distinctive silver finish

Syntace's Megafroce 2 stem is intended for all-mountain and downhill riding and comes in a range of sizes with a focus on torsional stiffness and weight savings. The 42mm wide bar clamp area stiffens up cockpits with bars wider than 700mm Titanium bolts help keep the weight low and strength high. - Stack height: 36mm - Weight: 132g (70mm)

The perfect fit The Bontrager Elite Blendr Stem provides easy solutions for accessory integration. This alloy stem is light and strong, and it gives you endless options to integrate lights, a computer and more with Blendr accessory integration. Product details - Blendr Elite allows seamless accessory integration - 4-bolt dual band clamp retains stiffness and reduces weight - Opposing 2-bolt steerer tube clamp - Uses M5 countersunk, corrosion-resistant steel bolts with 5.2Nm torque spec - Approved for carbon bars and steerer tubes - Suitable for both MTB or road use - Includes Blendr mono base and accessory mounts

A traditional, lightweight, alloy stem with increased compliance for road and MTB use. Light as carbon. Strong as hell. The super compliant 7050-T6 aluminum alloy Race X Lite bike stem is light enough for the road but strong enough for the mountain. It features a flip-flop 7 degree rise and 31.8 clamp that help it excel in lightweight versatility for a variety of hand positions. - 7050-T6, 3D, forged alloy construction - 4-bolt face plate helps distribute clamping load on ultra-lightweight handlebars - Angled steerer tube clamp spreads clamping pressure on steerer and is carbon friendly - Countersunk, corrosion-resistant steel bolts do not require washers - Dual clamp bolts are strategically positioned to evenly distributing clamping forces - This stem requires at least 5mm of spacers above and below the steerer tube clamp area - Go green and save green – Zero packaging means zero waste and zero extra cost

The forged alloy construction of the Bontrager Pro Blendr Stem delivers stiffness without compromising its light weight or sleek looks. Easy integration of lights, a computer, and more with the Blendr integration system make this stem a perfect upgrade for any bike. - Pro-level quality 31.8mm clamp diameter stem weighs less than many carbon stems - 4-bolt dual band clamp securely holds handlebar - Uses high-quality M5 corrosion-resistant faceplate bolts with 5.2Nm torque spec - Integrate accessories with included Blendr Pro base and Blendr XXX accessory mounts - Mounts intended for use with Ion and Trip, Garmin, GoPro and SRM accessories - Approved for carbon bars and steerer tubes - Safe installation requires 5mm spacer above and below stem - Included Blendr accessories: Pro Mono Base, Trip Computer mount, and High Ion Light mount

The Bontrager XXX Integrated Handlebar/Stem is a one-piece carbon bar/stem combo that brings clean looks and light weight to any road bike. Lightweight 100% OCLV Carbon construction offers a great road feel and control, while calibration marks and a flat front surface ensure easy lever installation. Features Di2 compatible ports for clean internal wire routing when integrated with Shimano EW-RS910 bar-mounted Di2 junction. Product details - Seamless accessory integration with Blendr - Flat surface front of bar for clean cable routing - Calibration marks allow precise, accurate and repeatable brake lever position - Variable radius, compact flare (VR-CF) shape offers wrist clearance in the drops - 100% OCLV Carbon construction - Internal relief channel eliminates need for additional spacer above stem - Safe for use with carbon and alloy steerer tubes - Compatible with Shimano EW-RS910 bar end Junction-A for cleaner Di2 routing

Strong, light, and capable An oversized 35mm clamp diameter MTB stem that offers increased strength and minimal weight The Kovee Pro 35 stem is the perfect centerpiece for cross country race bike. This lightweight stem is optimized for the latest XC mountain bike standard, with a 35mm clamp diameter that combines with a 35mm handlebar to provide a stronger, lighter system. - Oversized 35mm clamp diameter offers increased strength and minimal weight - 6061-T6, 3D, forged alloy construction - Laser-etched calibration marks make dialing in the perfect angle simple and repeatable - Compatible with both Knock Block and standard headsets and spacers - Knock Block system protects frame from impacts from over-rotation of bars and fork crown - Available in a wide range of sizes for today's mountain rider - High-strength, corrosion-resistant steel bolts - Approved for carbon bars

The Guide Trail Stem is lightweight, durable, and provides excellent steering response. Available in super short lengths for use on new-school trail bikes with wide bars, short rear ends, and long front-center geometry. - AL-6061-T6 aluminum construction - 3D-forged for increased strength, then CNC-machined - 4-bolt faceplate design - 31.8mm bar clamp - Bead-blasted, then anodized, finish

When stiffness and weight are the top on your list, you want Ritchey's SuperLogic C-260 Carbon Stem. This revolutionary design starts with a bar clamp that wraps a full 260-degrees around the handlebar to distribute clamping stress evenly through the handlebar, faceplate, hardware and stem body. Ritchey's first full-carbon stem, the C-260 features high-modulus carbon for stellar strength-to-weight ratio that translates into a solid but forgiving ride. And, the steer tube clamp uses three bolts and a curved slot to reduce clamp stress on the steer tube, so you can run carbon bars and a carbon steerer with no problem.

Stems need to be light, simple, and rock solid. Fizik checked all the boxes with their Cyrano R1 Stem. The Cyrano stem forms an integral part of Fizik's Spine Concept fitting technology. A four-bolt face plate provides excellent torsional stiffness, and the choice of lengths and angles ensures that your perfect fit is out there.

Make sure your fit is dialed in your race against the clock! Bontrager's Speed Concept Stem allows you to set up your Speed Concept bike for proper ergonomics and aerodynamics. Plus, the precisely integrated design keeps your super aero bike fast and looking pro! - Low-Near = 17° rise / 77mm length - Low-Far = 100° rise / 110mm length - Mid-Near = 50° rise / 67mm length - Mid-Far = 45° rise / 110mm length - High-Near = 80° rise / 67mm length - High-Far = 75° rise / 110mm length

The Madone is built as a seamlessly integrated machine designed to do one thing: go fast. Trek's Madone Integrated Bar/Stem is an important part of that integration. Available in a variety or widths and reaches so you can dial in your superbike specifically for you. - Compatible with model year 2016/17 Madone - Variable radius, compact flare (VR-CF) shape offers wrist clearance in the drops - 100% OCLV carbon fiber construction - Seamless accessory integration with Blendr - Blendr accessory bases and mounts sold separately

- 3D forged AL-2014 construction - Sizes: 50 - 130mm, 10 deg. angle - Suitable for 1-1/8" forks - Diameter handlebar clamp: 31.8mm - Headlock system for a secure front clamp fixation

Key features: - Blendr works with this simple formula: Stem + Base + Mount. Add accessory. - Bases for use with Bontrager XXX Blendr stem - Add any XXX accessory mount (sold seperately) for an elegant, integrated look

Salsa's Guide Stem is lightweight, durable, and provides excellent steering response on the road or trail. - Bead-blasted, then anodized - 3D-forged for increased strength, then CNC-machined - 4-bolt faceplate design for easy installation - Stack Height: 40

From road to mountain, Syntace's Force 109 stem offers a variety of lengths in a 6° rise with thoughtfully engineered features. It's oversized stem tube diameter offers increased stiffness, and titanium bolts shed unecessary weight. A 200 degree clamp face helps increase handlebar strength and fatigue life. - Stack height: 38.5mm - Weight: 118g (110mm)

Developed for longer-travel trail bikes, Promax's S-29 stem offers the perfect configuration to set you up for maximum comfort and control. Featuring an oversize extension tube and faceplate with massive clamping area, it’s sure to keep your bars stylishly in place through the most demanding terrain. These stems are cold-forged and CNC-machined from 6061-T6 aluminum for strength, low weight, and durability.

Promax Banger stems have a front-load design and can be used with either side up, providing a 5-millimeter drop or rise. Available with 48-millimeter and 53-millimeter extensions, they are cold forged from the highest quality 6061-T6 aluminum then CNC machined to enhance the shape and further reduce weight. - Stack height: 30.5mm

Promax's DA-1 XC mountain bike stem is 3D cold-forged, then CNC-machined from 6061-T6 aluminum to create a lightweight and strong stem. The two-piece faceplate features their bar-gripping DWT (Dynalock Web Technology), which increases the bar/stem interface.

Save your steerer tube and eliminate headset spacers with the Velo Orange Tall-Stack alloy stem. It gives your bike's cockpit a nice clean look. Available in Polished or Black, the 17-degree angle allows the stem to be level on most modern frames. And, you can use handlebar clamp shims to adapt to smaller handlebar clamp diameters, if you like. - Stack height: 75mm - Not recommended for use with carbon steerer tubes

- C-220 degree extra-wide bar clamp improves stiffness and fits most riser bars - 3D forged 6061 alloy - 42mm steerer height with 41mm faceplate width - 142g (90mm)

You really can have it all-the WCS C220 stem rivals the performance of the revolutionary C260 stem design, but it's quicker and easier to install and remove thanks to a press-fit handlebar clamp interface and forward-facing hardware. The WCS C22 84D Stem offers 6-degrees of positive or negative rise. First proven on the Ritchey Trail Stem, the C220 handlebar clamp design creates a more secure interface by wrapping a full 220 degrees over the handlebar. Bolt forces are aligned with the clamp so that the stem body 'embraces' the handlebar, which is less prone to damaging lightweight bars. This clamp design allows for a lighter faceplate and stem body with no sacrifice in strength or stiffness. The stem body is forged 2014 aluminum for further weight reduction. Premium quality CrMo steel bolts are used throughout. - Material: 3D forged 2014 alloy body - 4 x 4mm coated CrMo steel forward-facing faceplate bolts - 2 x 4mm coated CrMo steel offset steer tube clamp bolts - 5Nm torque max on all hardware - Compatible with all 31.8mm bars - Press-fit clamp design installs and removes like a standard stem - Angle: 84/6 degree - Steerer Height: 42mm - Faceplate Width: 42mm - Blatte finish - 121g (110mm)

For cross country and all-mountain riding, Dimension Trail Stems provide a broad array of sizing options, rigorously tested to ISO 4210 Mountain standards. - Constructed with AL-6061-T6 aluminum - Shot-peened finish - Dimension stems are not intended for use with carbon handlebars or carbon steerer tubes

For cross country and all-mountain riding, Dimension Trail Stems provide a broad array of sizing options, rigorously tested to ISO 4210 Mountain standards. - Constructed with AL-6061-T6 aluminum - Shot-peened finish - Dimension stems are not intended for use with carbon handlebars or carbon steerer tubes

A Trail-Rated, carbon-bodied, 31.8mm stem for mountain bikers seeking best-in-class performance, response, and vibration absorption. The M6 stem is designed to complement the look and ride feel of the ENVE M5 and M6 handlebars. - Bar Clamp Diameter (mm): 31.8 mm - Material: Carbon - S.H.I.S. Stem Clamp Diameter: 28.6 - Stem angle: 0-degree

Salt Pro Topload Stem with STC (Shark Tooth Clamping) inside the stem to help grip the bars, 48mm wide faceplate with central bore for reduced weight and unique side pocket detail. - Bar Clamp Diameter (mm): 22.2 - Steerer Clamp Diameter: 1-1/8-inch - Stem Type: Top Load

Salt Pro Front loading stem with STC (Shark Tooth Clamping) inside the stem to help grip the bars, 48mm wide faceplate with central bore for reduced weight and unique side pocket detail. - Bar Clamp Diameter (mm): 22.2 - Steerer Clamp Diameter: 1-1/8-inch - Stem Type: Front Load

An adjustable stiffness suspension stem that smooths out the ride by reducing the affects of impacts and road vibrations. - Unwanted vertical movement is absorbed by twin interchangeable elastomers - Stem retains torsional rigidity - Travel is limited to 1-2 centimeters - Made with 6061-T6 Aluminum - Includes 5 swappable elastomers (2 pre-installed, 3 additional) to customize the ride feel for your bike, weight, and riding style

- Intended for XC, Trail and All Mountain use - Machined to precision with 7075 aluminum for high strength & fatigue resistance at a very light weight - Interlocking 4 bolt bar clamp secures your bar and distributes loads away from bolts and into the body - Bar Clamp Diameter: 31.8 mm - Stem Angle: -84 deg , +96 deg