CYSKY Adjustable Bike Stem 31.8/25.4mm, 90mm Length, ±90° Aluminum Riser for MTB Road BMX

CYSKY's adjustable bike stem lets you change handlebar height and angle from -90° to +90° for a comfortable, custom riding position on most bikes.

If you want to tune handlebar reach and posture without replacing the whole cockpit, this 90mm aluminum stem provides a durable, tool-friendly solution. It accepts both 31.8mm and 25.4mm bars with the included shim, clamps to a standard 1-1/8" fork steerer, and uses CNC-forged aluminum for strength and low weight. The design is compact for a short-stem feel and supports a wide range of bikes from road and mountain to BMX and city bikes.

How does the angle adjustment improve my ride?

Changing the stem angle shifts your torso and wrist position quickly, letting you prioritize comfort or control depending on terrain and riding style. A negative angle lowers the bars for a more aerodynamic posture; a positive angle raises them for upright comfort.

• Adjustable from -90° to +90° to cover extreme positions and small tweaks
• 90mm length preserves short-stem handling with increased clearance options
• Solid clamp design maintains alignment when tightened

Will this stem fit my handlebars and fork?

The stem is built to work with standard 31.8mm handlebars and includes a shim to adapt to 25.4mm bars, making it versatile for most aftermarket and stock bars. The steerer clamp fits common 1-1/8" (28.6mm) front forks used on many bikes.

• Includes 31.8-to-25.4mm shim for two popular bar diameters
• Front fork clamp diameter: 28.6mm (1-1/8") fits most modern forks
• 90mm length is compatible with road, MTB, BMX, and city setups

How durable and lightweight is the construction?

This stem uses 3D-forged aluminum alloy with CNC machining to balance strength and low mass, giving a reliable platform without excess weight. The finish resists wear, and the material is chosen to avoid bending or rust during normal use.

• Precision 3D forged aluminum alloy for stiffness and impact resistance
• CNC surface finish that resists paint wear and is easy to clean
• Weight approximately 293g (0.65 lb) for a sturdy yet lightweight upgrade

What tools and extras come with the stem?

The package includes everything needed for installation and immediate fitment changes, so you can swap bars or adjust angle at home with the supplied hex keys. This makes it well suited for DIY upgrades and routine maintenance without hunting for extra tools.

• Includes one bicycle stem and one 31.8-to-25.4mm stem adapter (shim)
• Two hexagonal wrenches provided for clamping bolts and angle adjustments
• Clear bolt access and straightforward assembly steps for most riders

Who is this for: Cyclists who want a compact, adjustable stem to fine-tune riding posture or replace worn cockpit parts—mountain bikers, commuters, BMX riders, and road cyclists seeking a short, durable riser. It also suits home mechanics and riders updating older or hybrid bikes thanks to the included shim and simple installation. If you need a versatile stem that balances adjustability, weight, and durability for multiple bike types, the CYSKY 90mm adjustable stem is a practical choice.