Bicycle Stems, Wedges, Top Caps & Spacers — Fine-Tuning Your Riding Position

The stem connects your handlebars to your fork steerer tube and has a significant effect on your riding position, handling, and comfort. A few millimetres of stem length or a spacer or two can transform how a bike feels.

Stem Length and Rise

Stem length is measured from the centre of the steerer clamp to the centre of the handlebar clamp, typically ranging from 60mm to 130mm. A shorter stem makes steering quicker and more responsive; a longer stem gives a more stretched, aerodynamic position.

Rise refers to the angle of the stem — a positive rise lifts the bars for a more upright position, while a negative rise drops them for a more aggressive posture. Many stems are reversible, giving you two rise options in one.

Clamp Diameters — Check Compatibility

Stems have two clamp diameters to check:

• Steerer clamp — must match your fork's steerer tube: 1 1/8" (28.6mm) is the most common; 1.5" tapered steerers require a specific stem or adapter.
• Handlebar clamp — must match your bar: 31.8mm (oversized) or 25.4mm (standard) are the most common.

Spacers and Stack Height

Headset spacers sit on the steerer tube above or below the stem, allowing you to adjust bar height without cutting the steerer. Adding spacers raises the bars; removing them lowers them. Once you've found your ideal position, the steerer can be cut to length. Always leave a few mm of steerer above the stem top cap for preload adjustment.

Top Caps and Wedge Bolts

The top cap and bolt apply preload to the headset bearings, keeping everything tight and play-free. They don't clamp the stem — that's done by the stem's steerer clamp bolts. A loose top cap bolt leads to a rattling, loose headset. Wedge-style expander plugs are used inside carbon steerers instead of traditional star nuts.

Browse our stems, wedges, top caps and spacers to fine-tune your fit.