Park Tool Frame Alignment Gauge

If you have already ruled out a bent derailleur hanger and your wheel is true, but your bike still shifts poorly or tracks strangely, your frame dropouts may be misaligned. This tool is the definitive way to confirm if the frame itself is the source of the problem.

Yes, the gauge is highly versatile. Its retractable pointer and adjustable design allow it to fit almost any bicycle frame, including road, mountain, and hybrid bikes, regardless of the specific dropout spacing.

It is straightforward, but it does require a methodical approach. You essentially measure the distance from the gauge to the seat tube on both sides; if the measurements don't match, you have identified an alignment issue.

This is strictly a diagnostic tool for measuring alignment. It will tell you if your frame is straight or bent, but it does not provide the leverage or mechanical force required to bend a steel frame back into alignment.

The string method is prone to error because it is difficult to keep the string perfectly centered and clear of obstacles like cables or frame geometry. This gauge provides a direct, consistent measurement at the dropouts, which is where precision matters most for shifting and tracking.