Drivers · Facts checked Sep 2026
Is the Mizuno JPX ONE worth replacing your ST-G?
Upgrade only if…
You need a loft your driver doesn't come in.
The Mizuno JPX ONE is also sold in 9°, 12°. ↗
Otherwise, keep your ST-G.
Lofts you can buy Fact
| Model | 9° | 9.5° | 10.5° | 12° |
|---|---|---|---|---|
| ST-G (yours) | —not sold | ✓sold | ✓sold | —not sold |
| JPX ONE | ✓sold | —not sold | ✓sold | ✓sold |
Only the JPX ONE: 9°, 12°. Only yours: 9.5°.
What actually changes Fact
- Weights
- Yes, on a track vs Yes, movable weights
- Head volume
- 440 cc vs Not published Not published for the JPX ONE.
All specifications Fact
13 specs
| Spec | Mizuno ST-G (yours) | Mizuno JPX ONE |
|---|---|---|
| Launch priceLaunch price, not today's price. | Not available | Not available |
| Lofts | 9.5°, 10.5° ↗ | 9°, 10.5°, 12° ↗ |
| Hosel | Yes, ±2° ↗ | Yes, ±2° ↗ |
| Weights | Yes, on a track ↗ | Yes, movable weights ↗ |
| Standard length | Not available | Not available |
| Spec | Mizuno ST-G | Mizuno JPX ONE |
|---|---|---|
| Model year | 2023 | Not available |
| Sold as the brand's current driver | No | Yes |
| Hands | Right-handed and Left-handed ↗ | Right-handed and Left-handed ↗ |
| Head volume | 440 cc ↗ | Not available |
| Standard lie | Not available | Not available |
| MOI published by the brandWe never estimate MOI. Marketing figures for combined MOI are listed as claims, not facts. | Not available | Not available |
| Stock shafts | Not available | Tensei 1K Blue 55, Tensei 1K Black 65, Denali Frost Blue 50 ↗ |
| On the USGA conforming list | Not available | Not available |
Checked Sep 20, 2026 (ST-G) and Sep 20, 2026 (JPX ONE) on each brand's own pages. ↗ opens the official source. A newer model year is never a reason on its own.
What the brands claim Manufacturer claim
5 claims
Mizuno ST-G
- Mizuno pitches the ST-G as a low-spin head whose weight track moves between ultra-low and mid-low spin. ↗
- Brand says the CORTECH Chamber and a new Beta Rich titanium face give faster, more consistent ball speed. ↗
Mizuno JPX ONE
- Mizuno says its NANOALLOY face loses less energy at impact, raising initial ball speed. ↗
- The brand says a redesigned CORTECH face works with the NANOALLOY face to enlarge the high-speed area. ↗
- Adjustable hosel and weighting are pitched as a way to tune launch, spin and look. ↗
The brands' words, summarised. Not tested by us, and they never change a verdict.
Our take Our assessment (based on published specs)
2 min read
Neither driver has a published launch price, length, lie or MOI, so this comparison runs on a handful of rows. Both come in right and left hand, and both have a hosel that adjusts ±2°.
The fact that changes anything is loft. Your ST-G came in 9.5° and 10.5°; the JPX ONE comes in 9°, 10.5° and 12°. If you want to go a step lower than 9.5°, or you'd like a 12° head rather than cranking the hosel up, the JPX ONE covers it.
Weighting is set up differently. The ST-G has weights on a track, which Mizuno pitched as moving the head between ultra-low and mid-low spin; the JPX ONE has movable weights instead. The ST-G is 440 cc; Mizuno doesn't publish the JPX ONE's head volume. Mizuno says the JPX ONE's NANOALLOY face loses less energy at impact and raises ball speed. That is the brand's claim, without a number we can set against the ST-G.
Our read: keep the ST-G unless you need the 9° or the 12°. If you do switch, check on a launch monitor whether the movable weights do what the track on your ST-G does for your spin.
Quick answers
4 questions
Should I upgrade from the Mizuno ST-G to the Mizuno JPX ONE?
Only if one of these applies to you: you need a loft your driver doesn't come in: the Mizuno JPX ONE is also sold in 9°, 12°. Otherwise, keep the Mizuno ST-G.
What lofts do the Mizuno ST-G and the Mizuno JPX ONE come in?
Mizuno ST-G: 9.5°, 10.5°. Mizuno JPX ONE: 9°, 10.5°, 12°.
How do they adjust?
Mizuno ST-G — hosel: yes, ±2°; weights: yes, on a track. Mizuno JPX ONE — hosel: yes, ±2°; weights: yes, movable weights.
What did each one cost new?
The brand doesn't publish a launch price for the Mizuno ST-G. The brand doesn't publish a launch price for the Mizuno JPX ONE. These are launch prices, not what either sells for today.
Last updated 2026-09-21. The rules behind this verdict: How we rate. A verdict is not a fitting.