G-Shock Reviews

[G-Shock Review] GA-2100-1A — The Familiar Carbon Body

The Ultimate Guide to All G-SHOCKs — composed by Experts

When it comes to G-Shock, the first thing that comes to mind, of course, is three things – strength, power and a unique Japanese style that is not found in other watch manufacturers. Casio are stubbornly and methodically developing their technical developments in this niche, trying to compete with “neighbors” in the market [and they partially succeed], while not forgetting to periodically update the lineup with cases “from the past” – this was the case, for example, with DW -5700 and DW-5900. The secret to the success of these series is not in the technological stuffing and modern trends of smart gadgets, but in the audience’s special attitude to old-school models, which by and large are aimed at experienced fans of high-impact direction. Today’s review is about such watches – GA-2100-1A as a representative of the case, which has interested many fans of the “old guard” G-Shock.

GA-2100-1A1, GA-2100-4A, GA-2100-1A

The GA-2100 was seriously discussed in August this year [GA-2100 is an octagonal case, an-digi and carbon fiber], when the Japanese without any press releases or news posted on a full description of the case and the watch’s capabilities. Unlike the same DW-5900, they do not exactly repeat any of the models that came to us from the last century, which means that the designers managed to cross the legendary form factor and a completely new approach to the design of the case.

You probably already understood what I’m getting at – inside of the case is a polyurethane layer with carbon reinforcement. The manufacturer calls his creation the Carbon Core Guard structure, which not only helps to improve the impact-resistant properties of the case [carbon is a very durable material] but also reduces the weight of the watch, and this is also important. True to say, in the case of the GA-2100, carbon elements are completely hidden inside the watch, and you will not admire them visually [unlike the GA-2000 or GST-B200].

Another no less interesting detail is the shape of the case, which is now not round or even square, but octagonal. The number eight in this case is very arbitrary, because the dial still remained round, but the very idea of ​​the designers is respected. The octagonal bezel, which is responsible for the octagonal look, takes all the attention. By the way, the DW-5000C [the very first G-Shock] had a similar format, and it was this model that became the starting point not only for all subsequent “square” series, but also for the GA-2100 itself. Thus, in one building the glorious Jishokov past and modern durable materials coexist.

The outer “shell” of the case is made of ordinary polyurethane, so you can learn about carbon fiber either from the description of the characteristics or from the inscription on the back cover – it would be strange not to see any mention of such cool material there.

The strap is removable – small levers on the pins are responsible for removing both of its parts. This is already found in most modern G-Shock [even relatively inexpensive], so nothing surprising. There is no backward compatibility with the straps of the same DW-5600, but I think craftsmen will come up with custom options, unless of course the model shows good dynamics in sales.

Case dimensions are 48.5 × 45.4 × 11.8. The thinnest body of all G-Shock, even thinner than the DW-5600 [13.4 mm]. I do not have a single representative of the 5000th case in my hands, so I will compare it with what I have – my GG-1000 and GST-B200, compared to the 2100s, seem simply gigantic.

I personally like the dial. Nothing more – an electronic panel plus additional dial with an hand for the day of the week. The only drawback is the lack of an indication of the current mode, but this is an amateur. In any case, when switching modes, the corresponding signatures appear in the digital window, albeit not for long, but this is quite enough. The navigation between the modes is classic – switching occurs by pressing the lower left button of the clock.

The principle of displaying the date seemed a bit unusual – not the upper left button, as is most often the case, but the lower right one is responsible for changing the screen to the “day – month” format. The top performs a slightly different function – activates the display of the area code of the home zone [default TYO – Tokyo].

Now about the hour of the digital window. It is very small and is divided into two segments for a separate arrangement of information. For example, in stopwatch mode, hours and minutes are displayed at the top, and seconds are displayed at the bottom. Those who often and frequently use a stopwatch or timer are unlikely to appreciate such a move by engineers for one simple reason – small numbers do not affect readability in the most positive way. On the other hand, the size of the dial simply does not allow you to walk up even more by a millimeter – at the top of the arrow, on the right and at the bottom are hour markers, well, on the left, extra. window, and all this severely limits the size of the electronic window.

Since the digital display is inverse, there are questions about readability in the sunny time of the day, especially in bright light and at an angle. In this case, when reading the time, the analog zone saves, but when using the same stopwatch, you will have to peer.

The basic capabilities of the GA-2100 are limited to a stopwatch with a measuring range of 24 hours, a countdown timer, world time for 48 cities, five alarms, the Hands Shift function [switch hands to the neutral position], an hourly beep and an eternal calendar.

The backlight consists of two LEDs – one for the analog zone and the second for the electronic display. The logic of placing the LED for the dial in the lower right corner is a little incomprehensible, it would be more logical to place it at least on the left, because the electronic one is still illuminated separately. I personally rate the effectiveness of the backlighting as good; you don’t have to strain to read the information. I got a model with neobrite on the arrows [light-accumulating coating], the completely black GA-2100-1A1 does not have such a coating.

A battery with a life of 3 years is not the saddest option. I would like to have a solar, but the budget segment limits the possibilities of watches. Water resistant at 200 meters is the standard for the G-Shock.

“Specifications of GA-2100”]

  • Case / bezel material: Carbon / Resin 
  • Resin Band
  • Shock Resistant
  • Mineral Glass
  • 200-meter water resistance
  • Double LED light
    LED light for the face (Super illuminator, selectable illumination duration (1.5 seconds or 3 seconds), afterglow)
    LED backlight for the digital display (Super illuminator, selectable illumination duration (1.5 seconds or 3 seconds), afterglow)
  • World time
    31 time zones (48 cities + coordinated universal time), daylight saving on/off, Home city/World time city swapping
  • 1/100-second stopwatch
    Measuring capacity:
    00’00”00~59’59”99 (for the first 60 minutes)
    1:00’00”~23:59’59” (after 60 minutes)
    Measuring unit:
    1/100 second (for the first 60 minutes)
    1 second (after 60 minutes)
    Measuring modes: Elapsed time, split time, 1st-2nd place times
  • Countdown timer
    Measuring unit: 1 second
    Countdown range: 24 hours
    Countdown start time setting range: 1 second to 24 hours (1-second increments, 1-minute increments and 1-hour increments)
  • 5 daily alarms
  • Hourly time signal
  • Hand shift feature
  • Full auto-calendar (to year 2099)
  • 12/24-hour format
  • Button operation tone on/off
  • Regular timekeeping
    Analog: 2 hands (hour, minute (hand moves every 20 seconds)), 1 dial (day)
    Digital: Hour, minute, second, pm, month, date
  • Accuracy: ±15 seconds per month
  • Approx. battery life: 3 years on SR726W × 2
  • Size of case : 48.5×45.4×11.8mm
  • Total weight : 51g


GA-2100-1A will be suitable both as the first G-Shock, and will be the subject of interest for more experienced G-Shock fans who appreciate the Japanese past and believe in the future of the watchmaking craft of the land of the rising sun. The old-school design in the form of an octagonal bezel, the thinnest case [11.8 mm] and the carbon structure inside – it is quite possible that the manufacturer wants to make the 5600th series successor from the 2100s, only with a modern bias and an ana-digi display.

Read Quick News on GA-2100:

All News on GA-2100 →

Firstly published, but we carefully translated into English.

Some FAQ moments about G-Shock GA-2100 Series

What is 200 Water resistance?

G-Shock GA-2100 is suitable for professional marine activity and serious surface water sports, but not suitable for diving.

GA-2100 Profile / Casio G-Shock
Average Amazon Price: $100 (yes, we may earn a commission on qualifying purchases from our links to Amazon). Check the Price on Amazon →
Year of first release: 2019
Lineup: STANDART ANA-DIGI (This Line includes Digital and Analog displays on G-Shocks that are the best in “price/quality” category. Usually have traditional digital functions, but with beautiful hands. Don’t worry, the hands won’t prevent you from seeing digits, since there is a special Hand Shift technology that moves them to the neutral position) All G-Shock Standart Ana-digi Watches →
Best for: Small Wrists, Teenagers, Office and Formal Wear, Top in G-Shock Lookbooks
The most distinctive specs:
200-meter water resistance (good for swimming but not for deep diving)
Carbon Core Guard structure (protects the module by enclosing it in a carbon case. The case is made of fine resin embedded with carbon fibers for outstanding strength and crack resistance)
Other colors and full specs: GA-2100 Wiki Page
Only Limited Editions: GA-2100 Limited Editions

G-Shock GA-2100 Rating System

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