Logging CPM Before and After the Cut

Cycles per minute, or CPM, measures how fast a shaft oscillates when deflected and released while clamped at the butt end. It's a simple mechanical test, but it's the closest thing we have to an objective before-and-after reading of what a trim actually did to a given shaft, rather than what a published chart says it should have done.

Why We Never Skip the Baseline

Manufacturing tolerances mean two shafts of the same model and flex letter can leave the factory with slightly different raw CPM readings. If we only referenced the trim chart without measuring your specific shaft first, we'd be trimming to a theoretical average rather than the actual part in front of us. Every session starts with a baseline read, clamped and plucked the same way each time to keep the measurement repeatable.

What the Post-Cut Number Confirms

After the trim, we re-clamp and re-read the same shaft. A tip trim that follows the chart should move the CPM into a predictable range, and when it does, that's confirmation the cut behaved as expected. When it doesn't — which happens more often on older or previously repaired shafts than most golfers expect — it's a signal worth investigating before the shaft gets built into a club, not after.

The chart predicts. The board confirms. We don't consider a trim finished until both agree closely enough to trust.

Reading the Ticket

Both numbers go on your printed cut ticket alongside the trim amount, so you're not asked to take our word for what changed. A shaft that reads 268 CPM raw and 281 CPM after a 1.25-inch tip trim has a documented, repeatable story behind it — useful reference if you ever need a matching shaft built the same way down the road.

The Takeaway

A trim chart is a starting point, not a guarantee. Logging the actual CPM before and after every cut is what turns a chart-based estimate into a verified, repeatable spec.