G-SHOCK GA-2100 1A: Review

I’ve never owned a G-SHOCK. I have small hands and a relatively narrow 6.5” wrist – not the best place to put a large, chunky watch. And then the GA-2100 series caught my eye – and fit my wrist. Thanks to its Carbon Core Guard architecture, the GA-2100 is the thinnest analog-digital G-SHOCK’s ever made. It’s also a very affordable $99. Well, it was until sales of the “Casioak” went nuts . . .

Casio G-SHOCK GA2100

The Casioak nickname springs from the GA-2100’s resemblance to the Audemars Piguet Royal Oak, both in terms of looks and, now, unavailability. The aesthetic similiarites between the two watches are certainly there: octagonal bezel, minimalist design and perfectly integrated bracelet. But Casio says no. They claim the original DW-5000C inspired the GA-2100.

Casio G-SHOCK DW-5000C

To be fair, the original DW-5000C did have an eight-sided bezel. And a matte finish. And a case perimeter with smooth sides and castellated surfaces between the sides and the lugs. And four chrome pushers located at 2, 4, 8 and 10. But if AP were to make a Royal Oak ani-digi, the GA-2100 would be it.

Red Casio G-SHOCK GA-2100

Colorways-wise, when launched, Casio offered the GA-2100 1A (black with white hands and light gray indices), the GA-2100 1A1 (the “stealth” version with black with gray hands and black indices) and the GA2100 4A (red with red hands and indices). I chose the the white-on-black 1A – it’s more legible than the gray-on-black 1A1 and I’m not flashy enough to rock a fire engine red watch.

(courtesy scottishwatches.co.uk)

With a case diameter of 45.4 mm, the G-SHOCK GA-2100’s a fire engine big watch, significantly larger than the largest Royal Oak (41mm). The GA’s a bit outside my timepiece comfort zone, but it doesn’t wear large. Credit the GA-2100’s diminutive height (18mm), lug length (47mm) and weight, tipping the digital scales at just 1.8 ounces (51 grams) including the resin strap.

Close-up G-SHOCK GA-2100

The GA-2100 sword-shaped minute and hour hands won’t please lumatics, but the lume’s bright enough for one-handed time check in the dark, and they save battery power. It’s too bad the G-SHOCK GA-2100 didn’t place lume dots near the indices. Never mind. The on-board illumination button triggers both a back light for the digital screen and a LED for the analog display. Sorted.

All three of the original GA-2100 versions have a negative liquid crystal screen with light colored letters. In the case of the 4a, it’s a red screen. The other two are black (actually dark blue), blending in well with the rest of the watch face. There’s a supplementary half dial – indicating the day – next to the 9 o’clock index, and a small digital screen positioned in the lower right quadrant. In Timekeeping mode, they can be toggled between date/seconds and time/seconds.

G-SHOCK GA-2100 white hands

The GA-2100 uses Casio’s 5611 module. It delivers a small feature set for a G-SHOCK: analog and digital time, stopwatch, world time, perpetual calendar (good through 2099), five daily alarms and a countdown timer. The power source is also pretty basic (no advanced solar power system or long life battery). The two SR726W cells are supposed to last three years.

The GA-2100’s quartz movement is made in Japan. My watch was cased in Thailand. Japan-cased watches carry the JF suffix, at a price premium of about 40 to 100 percent. Considering G-SHOCK’s automated assembly, I’m not sure it makes any difference where the factory is located, at least in terms of quality. That said, the GA-2100’s still a hundred dollar watch. Under a macro lens you can see that the hands’ finish is a bit spotty. The flaws aren’t visible to the unaided eye at a normal distance.

As delivered, the GA-2100’s minute hand was off by 20 seconds. According to the User’s Guide, the analog hands can become misaligned due to “strong magnetism, impact, or other abnormal conditions.” That’s a bit surprising coming from G-SHOCK, a brand whose name implies impact resistance. But it’s not a big issue; the hands are easily fine tuned per online instructions

Running through the functions and setting the watch is straightforward – with a bit of optional theater. To begin, you set the watch digitally. Once the time is set, the analog hands motor around the dial to the correct time. Should a hand or both hands obscure the digital screen, pressing the light and mode switches rotates the hands away from the screen. A touch of the mode button returns them to their proper positions. In normal use, the minute hand leaps forward a precise third of a minute every 20 seconds.


The G-2100’s water resistance is rated to 200 meters. Casio’s traditional four-screw stainless steel caseback is engraved with the Carbon Core Guard logo. Bonus! Quick-release pins hold the rubber in place (tool required). Should Casio introduce other colors, you’ll be able to mix and match the straps.

The G-SHOCK GA-2100 doesn’t all the digital bells and whistles associated with the brand. It’s form-follows-function minimalism combined with G-SHOCK durability, reliability and rugged good looks. Is it worth a premium? That’s up to you. I don’t think we’ve seen the last of this model. Definitely not on my wrist.

UPDATE: As we were preparing this review for publication, another three color schemes have gone on sale. The “1990s throwback” models include the GA-2100THB-7AJF, with a white case, white indices on a black dial, and two-tone purple and pink resin band, and the GA-2100THS-1AJR with a purple bezel and blue indices and hands. With its gold hands and red and green indices the black bezeled GA-2100TH-1AJF would be perfect for the Christmas season if any vendors can deliver at this late date.

Casio G-SHOCK GA-2100
Retail price: $99 (out-of-stock just about everywhere, street price $339)


Case: Resin outer case, Carbon Core, Stainless steel caseback
Diameter: 45.4mm
Lug length: 47mm
Lug spacing: 16mm between the lugs
Case thickness: 11.8mm
Crystal: Mineral Crystal
Strap: Resin
Clasp: Stainless steel strap buckle, Casio branded on reverse
Movement: Casio 5611 quartz analog/digital
Accuracy: ±15 seconds per month
Functions: Analog minute and hour, Digital minutes, hours, seconds, 12/24 hour formats, Digital month, date, Analog day, World time, Stopwatch 1/100 sec – 24 hrs, Countdown timer, Five setable alarms, Auto calender to 2099
Power reserve: 3 year battery life (SR726W × 2)
Luminescence: Neobrite on hands only (1A and 1A1 models), LED dial light, LED backlight for digital display
Water resistance: 20 bar (200 feet)

RATINGS (out of five stars):

Design * * * * *
A more traditional horological take on the rectangular G-Shock Square, channeling the spirit of Gerald Genta. The main reason the GA-2100 is a huge success.

Legibility * * * *
White-on-black model’s analog hands are fine, “stealth” gray-on-black, and red-over-red models not so much. Digital screen is hard to read in direct light but on-your-wrist legibility is fine.

Tactility * * * * *
Function pushers are ergonomic and out of the way, while giving the matte resin case some visual pop.

Comfort * * * * *
Weighing just 51 grams including the strap and less than 12mm thick, you’ll forget you’re wearing it – until you need it.

Overall * * * * *
An attractive, minimalist feature analog/digital G-SHOCK that puts a traditional spin on classic Square aesthetics. A smart brand extension that’s entranced both G-SHOCK fans and traditional watch enthusiasts. Mine’s not for sale.

BUT you can win your very own box fresh G-SHOCK GA-2100 by entering The Truth About Watches ‘comment contest. Click here for the rules. Winner selected on March 15, 2020. We will never share you email address with any third party. Good luck!

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