For months you’ve been asking us: what’s the real difference between rubber and metal springs? So we tested every light spring from the major Pilates equipment brands, Merrithew, BASI, Balanced Body, Aero, and of course Somato.
We measured the resistance at three lengths, then plotted them on a graph so you can see the full force curves side by side. The results? Every brand has its own curve, but they’re all surprisingly close, within about 2lbs of the average force. The Somato rubber spring sits right in the middle.
Our key takeaways:
1. No two brands are exactly the same. There is always going to be variation, even between different metal spring brands. Whether you're switching between a Merrithew and Balanced Body reformer or a BASI and a Somato reformer, you will have to make minor adjustments in your springs settings. Our Somato coaches will help you through those adjustments by recommending spring settings for every exercise.
2. Rubber springs are slightly stronger than metal springs when stretched at shorter distances and slightly weaker at longer distances. This means you'll feel more challenged or more supported (depending on the exercise) when the Carriage is closer to the front of your Somato reformer.
So what makes Somato’s rubber springs different from the bungees you might know?
The takeaway: there’s no single “right” spring, only what feels right for your workout. But if you’ve ever wondered how rubber stacks up against metal, this is the comparison you’ve been waiting for.
