Aynaxcol 31.8mm Adjustable Bicycle Riser Stem, 90mm Length, 0–90° Tilt, 3D-Forged Alloy

Aynaxcol 90mm adjustable riser stem is a 3D-forged alloy bicycle stem that fits 1-1/8" (28.6mm) steerer tubes and 31.8mm handlebars, offering a 0°–90° tilt range for customizable upright or aggressive riding positions.

Whether you need a taller, more comfortable posture for commuting or a forward-leaning stance for faster riding, this stem gives precise angle adjustments and clean internal cable routing for modern e-bikes and bikes with external controls. Engineered from 3D-forged alloy, the unit is built to resist handlebar rotation while remaining lightweight and easy to install.

How does this stem change my riding position?

The wide 0°–90° adjustable range lets you convert a low, sporty cockpit to a relaxed upright setup without swapping stems. Fine-tune the tilt using the single adjustment bolt and then lock the clamp bolts to secure the chosen angle.

• 90mm length provides noticeable reach while keeping control and stability
• 0° gives a low, aerodynamic profile; 90° delivers a tall, upright view
• Single-bolt angle adjustment for quick on-bike changes
• 31.8mm handlebar clamp maintains compatibility with modern bars

Will this fit my bike and handlebar setup?

This stem is designed specifically for bikes with a 1-1/8" (28.6mm) steerer tube and handlebars with a 31.8mm clamp diameter. It is not compatible with 1" steerer tubes or 25.4mm handlebars, so measure both parts before purchasing.

• Compatible steerer: 1-1/8" = 28.6mm only
• Handlebar clamp: 31.8mm only — not for 25.4mm bars
• Check headset spacer stack and cable routing clearances before fitting
• Suitable for most modern mountain, hybrid, and e-bike front-ends

Is it durable and safe for everyday or e-bike use?

Built from 3D-forged alloy, the Aynaxcol stem is engineered to prevent unwanted handlebar movement and maintain reliable clamping force. The construction and bolt layout are suitable for commuting, trail rides, and electric-bike control loads when installed correctly and torqued to specifications.

• 3D-forged alloy resists deformation under load
• Multiple clamping bolts reduce slippage risk
• Designed to handle two routed cables inside the stem for neat e-bike setups
• Follow manufacturer torque specs and periodic bolt checks for safety

How easy is installation and cable routing?

Installation is straightforward: mount to a 1-1/8" steerer, clamp a 31.8mm handlebar, set the angle with the adjustment bolt, and tighten the clamp bolts. The internal routing channel accommodates two cables, helping to keep the cockpit tidy and protected from snagging.

• Simple angle adjustment with a single adjustment bolt
• Internal cable routing handles up to two control cables
• Typical install requires basic Allen keys and standard torque wrench
• Check headset preload and bolt torque after initial ride

Who is this for? The Aynaxcol adjustable riser stem is ideal for riders who want a single part to fine-tune cockpit height and reach—commuters who prefer an upright view, cyclists who switch between relaxed and aggressive positions, and e-bike owners who need tidy internal cable routing. It suits bikes with a 1-1/8" steerer and 31.8mm handlebars and is aimed at people comfortable checking fit and torque during installation rather than riders needing plug-and-play compatibility with 1" steerers or 25.4mm bars.