How to Use a Flat Bar Adaptor with Your Stem Mount
By Quad Lock USA® - Official Store | Published: 2026-10-28
Category: How-to Guides
Learn how to install the Quad Lock Flat Bar Adaptor on a flat handlebar or square stem for a secure bike mount. Step-by-step guide with tips.
Quick answer
Use the Flat Bar Adaptor to attach your Quad Lock Stem Mount to a flat handlebar or square stem. Insert the adaptor between the bar and the mount, then secure with zip ties.
Why you might need a Flat Bar Adaptor
The Quad Lock Stem Mount is designed for round stems and handlebars. If your bike has a flat handlebar or a square stem, the mount won't sit flush or grip properly. The Flat Bar Adaptor fills that gap and provides a stable surface for the mount to clamp onto.
This adaptor is a low-cost accessory that saves you from buying a completely different mounting system. It works with the included zip ties and o-rings for extra security.
Trade-offs and limitations
The Flat Bar Adaptor adds a small amount of thickness between the mount and the bar. On very narrow handlebars, this may reduce usable space for other accessories. Also, the zip-tie method is secure but not as quick to remove as a clamp; plan for a semi-permanent installation.
How to install the Flat Bar Adaptor
- Prepare the mounting area: Clean the flat handlebar or square stem surface where the adaptor will sit. Remove any dirt or grease so the zip ties grip firmly. A clean surface prevents the mount from slipping during rides.
- Position the Flat Bar Adaptor: Place the adaptor on the flat bar or stem, aligning it with the spot where you want the Stem Mount. The adaptor should sit flush against the bar surface. Make sure the adaptor is centered and not tilted, or the mount may be crooked.
- Attach the Stem Mount on top: Set your Quad Lock Stem Mount over the adaptor so the mount's clamping surface contacts the adaptor evenly. The adaptor acts as a shim between the bar and the mount. Do not skip this step: the mount must press directly onto the adaptor, not onto the bar.
- Secure with zip ties: Thread the supplied zip ties through the mount and around the bar or stem. Tighten them evenly until the mount feels solid and does not wiggle. For extra security, add o-rings (not included) around the mount before tightening. Zip ties should be snug but not over-tightened to avoid damaging the mount or bar.
- Check stability before riding: Give the mounted assembly a firm push in all directions. If it moves at all, tighten the zip ties further or add another zip tie. Ensure the phone cradle is accessible and does not interfere with handlebar controls. A loose mount can cause your phone to fall or damage the stem mount. Test it before every ride.
Product details
- Stem Mount - Flat Bar Adaptor: 45mm length x 29mm wide, includes 2 zip ties and recommends o-rings for extra security. The compact size fits most flat bars and square stems, and the zip ties ensure a firm hold without special tools.
Stem Mount - Flat Bar Adaptor
