TheStack Speed Trainer
5 CNC-milled weights enable 30 weight combinations from 0g to 300g, paired with TheStack App's adaptive speed training (4.9 stars, 5,500+ App Store reviews). Available in Adult (41.5") and Junior (38.5") sizing. Speed radar sold separately (Stack Radar recommended).
Why we curate
Why this earns the slot.
Specifications
Everything you need to know.
| Training Club | Adult 41.5" or Junior 38.5" (variant choice) |
| Weights | 5 CNC-milled (30 weight combinations) |
| Weight Range | 0g to 300g |
| Weight Case | Dual-purpose (case + phone stand) |
| Speed Radar Required | Yes (Stack Radar recommended, sold separately) |
| App Membership | 1 Year (iOS full, Android Beta, Web Beta) |
| App Includes | Speed training, Stack Wedging (iOS), Stack Putting (iOS), Learning Library |
| Family Sharing | Up to 20 local users per login |
| App Rating | 4.9 stars, 5,500+ App Store reviews |
| Designer Credits | Dr. Sasho MacKenzie (PhD Biomechanics), Marty Jertson (former PING lead engineer) |
| Average User Gain | 10.1 mph clubhead speed |
| Distance Potential Gain | 27.1 yards driver carry (average) |
| Coaches License | Available separately for instructors |
What's in the box
What's in the box, and what isn't.
- 1× TheStack training club (Adult 41.5" OR Junior 38.5", per purchase selection)
- 5× CNC-milled Stack weights (30 weight combinations: 0g to 300g)
- 1× Dual-purpose weight case / phone stand
- 1-Year Membership to TheStack App
- Bundled access to Stack Putting (iOS), Stack Wedging (iOS), and the Learning Library
- Not included Speed radar (Stack Radar sold separately, or use a compatible third-party device)
About this product
The data-backed speed training system.
A speed training system built around TheStack App's adaptive programs. Raise your speed ceiling and lower your scores with personalized training programs, guided workouts, and effortless data entry powered by TheStack App. Start training smarter to make more birdies, have more fun, and play your best golf.
TheStack Hardware
- 5 CNC-milled Stack weights enabling 30 weight combinations between 0g and 300g
- Dual-purpose weight case that doubles as a phone stand during training
- Precisely engineered training club: Adult (41.5") or Junior (38.5") version selected at purchase
- Speed radar required for training (Stack Radar recommended, sold separately)
TheStack App
Rated 4.9 stars with 5,500-plus App Store reviews. Adaptive speed training programs formulated by Dr. Sasho MacKenzie, golf's leading speed researcher. Guided workout timer for reps, sets, and rest intervals. Custom speed metrics to track your gains. Bluetooth connectivity to integration devices, plus hands-free voice entry technology for non-integrated devices.
Membership includes bundled access to Stack Putting (iOS), Stack Wedging (iOS), and the Learning Library. Train and track up to 20 local users under one login with Family Sharing. Connect with other Stackers using Share Codes.
The data behind it
The Stack System represents the largest study into variable inertia weight training in golf. 75,000-plus dedicated users, 45 million swings recorded, and an average gain of 10.1 mph clubhead speed (equating to 27.1 yards in driver distance potential). Designed by Dr. Sasho MacKenzie (PhD Biomechanics) and Marty Jertson (lead engineer at PING for 20-plus years, six-time Major Championship competitor, inventor on 125-plus patents).
Matt Fitzpatrick (2022 U.S. Open Champion): "I'll be honest. TheStack has worked wonders."
Platform availability
- iOS: Full features (Speed, Wedging, Putting, Learning Library). Requires iOS 15.0 or newer.
- Android (Beta): Speed + Learning Library available now; Wedging + Putting coming in a future update.
- Chrome Web (Beta): Speed + Learning Library available now; Wedging + Putting coming in a future update.
Are you a coach? A Coaches License is available separately for instructors.
