Promax Ahead Adjustable Stem

This stem is designed for handlebars with a 31.8mm clamp diameter, which is the current industry standard for most modern mountain and road bikes. If your handlebars are an older or different standard, such as 25.4mm or 35mm, this stem will not be compatible.

The stem features a wide adjustment range from -25° to 90°. This allows you to significantly raise your handlebar height for a more upright, comfortable riding position or lower it for a more aggressive, aerodynamic stance.

While the aluminum construction is durable and the four-bolt faceplate provides a secure grip, this stem is primarily designed for comfort and ergonomic adjustments rather than heavy-duty trail or downhill riding. It is best suited for commuting, touring, or casual recreational cycling.

Yes, it is designed for a standard 28.6mm (1 1/8 inch) threadless steerer tube, which is the most common size found on modern bicycles. Ensure your fork's steerer tube matches this diameter before installation.

The weight reflects the robust aluminum construction and the mechanical hardware required for the adjustable hinge mechanism. While it is heavier than a fixed-angle stem, the trade-off is the ability to fine-tune your bike's geometry without needing to replace the entire component.