Ex-Shopify engineer used a 20-day sabbatical to prototype the Intensity Pad: a struck pad plus iOS app that measures sledgehammer strike power in real time.
Key Takeaways
The core thesis: unmeasurable movements don’t become programmable ones; sledgehammer striking is a fundamental human movement with no instrumentation equivalent to cycling power meters or rowing ergometers.
Hardware timeline: parts ordered week one, sensor mount and connector failures in week two, a costly mechanical design mistake committed day four and abandoned day twelve after eight wasted days.
By week four the prototype survived real strikes, the control unit survived drops, and an iOS app was pulling live data – calibrated by hundreds of swings in a basement.
The product bar is explicitly not “gadget” but replication of what cycling power meters did: build a numerical bridge to better training intuition for a class of movement people already find compelling.
Prior relevant founder experience: sourced and sold weightlifting equipment during the pandemic, learning logistics and customer service hands-on.
Hacker News Comment Review
Technical commenters pressed hard on the engineering gap the post skips entirely: how is output power calculated, how much energy is lost to pad dampening, and how does the sensor survive repeated shock loads – none of it addressed in the article.
A meaningful thread questioned LLM involvement in the writing, with the author confirming placeholder AI images on the landing page and noting the site is unfinished, which blurred trust in the narrative.
The cycling-power-meter analogy resonated with cyclists in the thread, but one commenter who adopted Stryd for running power warned that raw numbers alone don’t transfer – the surrounding ecosystem of zones, coached workouts, and community knowledge matters as much as the sensor.
Notable Comments
@jrflo: asks the core unanswered engineering questions – power calculation method, accuracy validation, dampening losses, and long-term durability under shock.
@digitallogic: confirms the power-meter intuition shift from cycling but flags Stryd as a cautionary tale: numbers without tribal knowledge and prescribed workouts failed to stick.
