Bike Stem Alignment Tool.

This is a 3D-printable alignment tool designed to help you accurately center your bike stem over your front wheel. Originally modeled for a Trek Checkpoint ALR 3 Gen 2, it provides a simple, repeatable reference point when installing or adjusting stems—removing the guesswork and improving alignment precision.

Overview
The tool securely clips over your handlebars and centers perfectly over the stem, creating a centered visual guide. A built-in alignment notch lets you sight directly down the bike’s centerline to the front tire tread. It can be used by eye or paired with a laser pointer or plumb bob for increased accuracy.

Specifications & Fit
Handlebar Diameter: Designed for standard 31.8mm diameter handlebars
Stem Interface: Accommodates most stock stems and faceplate hardware, including Bontrager-style setups