Promax MQ-579-5 Quill Stem

This stem is designed for bikes with a 28.6mm steerer tube, which is common on many hybrid and vintage-style frames. Before purchasing, confirm your bike uses a quill-style stem rather than a threadless system, as they are not interchangeable.

The adjustable angle allows you to raise or lower your handlebar height without needing to replace the stem. It is particularly useful if you want to experiment with a more upright, comfortable riding position or need to fine-tune your fit for longer commutes.

Yes, this stem features a 25.4mm bar clamp diameter, which is the standard size for most city, hybrid, and vintage road handlebars. If you have oversized mountain bike bars, they will not fit this clamp.

The quick-release mechanism is designed for convenience when adjusting your position, but it locks securely to ensure stability while riding. It is a reliable solution for casual cyclists and commuters who want to customize their cockpit ergonomics on the fly.

Adjusting the stem from 90 to 140 degrees will significantly alter both your handlebar height and your reach. Moving toward the 140-degree setting will bring the bars closer to your body and higher up, creating a more relaxed, upright posture.