Grand Seiko's Spring Drive is like a stunning, vividly moving landscape. On a whitish-gray dial depicting a snowy midwinter mountain, a deep cobalt blue hand slides without any hesitation. When a phrase 'flowing second hand' becomes not just an expression, but the most accurate description of what I am seeing. We wonder if there is any magic in this landscape. I hear nothing, with my breath held, with my ears on. This is magic, or at least a silent revolution. Just as the silent snow repaints the landscape in a completely different color, Spring Drive is silently repainting the scenery we expect from a luxury watch. SangHwalWatches Presents English subtitle - Seokmin Ko (M.D. SangHwal) A silent revolution A silent revolution Grand Seiko SBGA415 There are many ways to pay tribute to Grand Seiko SBGA415. You can praise how sharp the Zaratsu polish on the case and dial is.

You can praise for how the distinctive dial pattern crafted through a complex process reveals a variety of faces depending on the illuminance or direction of light. It can be praised that it's light enough to forget that it's on your wrist because the case and bracelet are crafted from high-grade titanium. But today, I would like to spend a little time on the principle of the spring drive, which operates behind the second hand, which glides smoothly without any interruption. It is a strange product that can be considered as mechanical or quartz but can also be considered to be a separate species that does not belong to either side. Spring Drive boasts a quartz-like accuracy with a daily error within the range of +-1 seconds while maintaining the attractive feel of a mechanical watch. How is that possible? 
Once you look at the back through the caseback, you realize that it's not much different from most automatic watches. As you see, it has a structure that is not different from that of a general automatic watch, from the rotor to the mainspring to the gear train.

In other words, it is basically a movement that does not use any batteries and is powered by a spring. As other automatic movements, the crown can be wound by hand or by means of a rotor that rotates as the watch moves. The process in which power is transmitted from the barrel to other wheels is the same as with a usual mechanical movement. But it is from then on that the spring drive is different from the mechanical movement. There is something else in place of the escapement. In mechanical movements, there is a device called an escapement to control the speed at which the gears rotate. Without an escapement, the mainspring would unwind too quickly, causing the hands to spin at a staggering speed. It's unable to function as a watch. The balance makes an amplitude movement at regular intervals and controls the escape wheel through the pallet fork. As the escape wheel adjusts the speed of the other gear wheels with the precisely spaced rhythm it receives. Finally, it becomes a movement with a certain degree of accuracy.

In the mechanical movement, there is a tick-tick sound that is generated when the escape wheel and the pallet fork engage during this process. Mechanical escapements have two disadvantages. No matter how accurate the escapement is, it cannot be expected to be as accurate as quartz. It is also easy to be affected by external impact, gravity, and temperature change. Each time the escape wheel and the pallet fork engage, significant impact and wear occur, which requires a lot of maintenance. Spring Drive is trying to solve these two disadvantages by equipping a device called a Tri-synchro-regulator in the place where the escape wheel and pallet fork should be. What you see from the outside is a part called a glide wheel that is similar to the balance wheel at a glance. The glide wheel doesn't move left and right but rotates continuously in one direction without a tick-tick sound. This is why there is no sound from the spring drive and the reason why the second hand of this movement moves smoothly without hesitating.

The glide wheel acts as a generator turbine (using power from the mainspring) in a battery-free spring drive. A minimum amount of electric power is generated to vibrate the quartz crystal and to operate the IC chip. Powered by the electricity made by the glide wheel, the quartz crystal vibrates 32,768 times per second, providing a reference for the watch's accuracy. The IC chip compares the rhythm of the quartz with the speed of the glide wheel and applies the brake using an electromagnet if the glide wheel is too fast. With the help of quartz crystals and integrated circuits, the glide wheel rotates exactly eight rounds per second, regulating the speed of the other gear wheels. In summary, Spring Drive is an innovative movement that has the feeling of use of a mechanical movement and shows an accuracy comparable to that of quartz movement even without a battery. It is known that development took a very long time. Under the motto of developing a hybrid movement that combines the advantages of mechanical and quartz, it has been carried out since 1977.

Perhaps the idea of the basic principle was established early that the first prototype was unveiled in 1982. It took a long time to make a quartz regulator small and efficient enough to be commercialized. It first appeared in the domestic market in 1999, and it was introduced to the global market in 2005. There have been many attempts to combine the advantages of mechanical and quartz, but none have shown such an attractive combination as a spring drive. Although it does not advertise as loudly as other companies, it silently is changing the history of the watch movement. Coincidentally, the movement itself makes almost no sound. SBGA415 is showing the spring drive in a really attractive exterior and specifications. Taking advantage of titanium, it weighs only 102g before the bracelet is reduced. It is water resistant to 100m and has a screw-down crown, so it looks like a dress watch, but it can also be used as a sports watch. The case diameter is 40.5mm, and the lug to lug is 46mm.

Due to its distinctive bezel-less design, the dial is quite large, but its lug to lug is not too long. It is a bit large for a traditional dress watch, but it is a very suitable size for an everyday watch. It seems to be slightly smaller than other Grand Seiko watches based on the 44GS design. The signature multifaceted and angular case tends to have a large presence compared to its size. The 44GS, Grand Seiko's most iconic design, tends to be particularly so. However, the SBGA415, which follows the design of the 62GS, has a more nimble feeling. The original 62GS is Grand Seiko's first automatic watch. It is a design with a formidable heritage even though it is not as famous as the 44GS. Titanium, which is difficult to manufacture, is used, but the finish of the case and bracelet is never inferior to that of the steel model. The multi-faceted contours and the case that effectively contrasted the polish and brushes are enough to make you feel euphoric in close-up shots.

Of course, you can feel the charm of the shiny and clear Zaratsu Polishing again this time. But this watch is characterized by a higher proportion of brushes than other models. This is good news for those who were worried about the polished case being scratched. It is equipped with a box-shaped sapphire crystal with internal anti-reflection coating. 12.8mm thick with domed glass. The shape of the side is not so wide that it feels less thick than the number. Unlike the other Grand Seiko models, the thickness is not so emphasized. The lug width is 21mm, so it's not easy to find the proper aftermarket strap. Instead, it is equipped with a drilled-lug design so that you can exchange straps easily without scratching the case. It has a slightly more sporty feel, as you can see in drilled lug design. The crown is 5.25mm in diameter and has initials engraved on the front. The size and edge shape are excellent, so it is very comfortable to maneuver. It delivers a smooth, immediate response.

The hand-winding taste is incomparable to the ordinary Seiko. However, it is different from the Swiss movement, and it feels like you are manipulating a zipper. If you have a chance, I recommend you try it out. If you try it for the first time, you will be very surprised. The dials of the Grand Seiko are not the best for the price, but they are good enough to claim to be the best in the industry. These stunning patterns are possible because the dial is made in a labor-intensive way, where a basic pattern is applied to the metal plate and then a thin matte coating is applied several times. I hope the camera captures the changing texture of white, silver, and gray that depending on the direction of the light. According to Grand Seiko's explanation, this dial has the theme of '大雪-たいせつ' in the 24 solar terms. It is said to depict a landscape with sunlight falling on trees covered with snow.

A delicate pattern on a gray dial abstracts the scene where the overnight snow on the branches shimmers in the morning light. Of course, the company's explanation and the feeling you receive may be different, and I don't think it's a bad thing. Another charm of the Grand Seiko dial is that you can achieve a different image for each viewer, as they use a sufficiently abstract pattern. The multi-faceted indices and hour and minute hands made of steel are so neatly finished that no flaws can be seen no matter how I zoom the camera. The indices with sharp outlines are like computer graphics that even feel as transparent as crystals when immersed in light. The Dauphine Hands have clear outlines, and the dramatic use of the contrast between the polish and the brush stands out. You'll understand why YouTube watch channels, who have invested so much in filming equipment, love to shoot Grand Seiko. The date window has a clean-neat frame, and the power reserve indicator was finished by two textures to express depth and sophistication.

It's nice that the heat-treated dark blue second hand serves as the only accent on the dial. The only weakness of the Grand Seiko is the bracelet.
The case, dial, and movement are impeccable, but critics point out that the bracelet is a bit lacking. First of all, it seems that the connection between the links is rather loose rather than tight, and the push-button clasp is also rather plain. Instead, this time it is made of titanium, so it is lighter and more comfortable to wear. Some criticize Grand Seiko that they share a bracelet with the same design, instead of designing a bracelet for each watch.
I think this can be regarded as one of the signature elements of Grand Seiko. The length adjustment is done by a push-pin method, and even without fine adjustment, there are some shorter links, so it is possible to adjust it to a certain extent. The caseback is screw-in type, and the movement can be observed through the sapphire crystal caseback.

A glide wheel that rotates in only one direction is interesting to see, and I don't think it was a good choice to cover the movement with a company logo sticker. Usually companies that are not confident in the aesthetics of the movement do this, but Grand Seiko has no reason to hide the movement. I hope they reveal it cool next time. So, let's summarize today's review. The dial and case finish that are comparable to tens of millions of won high-end watches are compliments that you have heard many times in other reviews. Perhaps the reason why such good reviews continue is probably because it is an undeniable fact. SBGA415's special feature is that it uses high-grade titanium material and has a water-resistance of 100 meters, so it is very practical in specification. It can be used as a dress watch or as a sports watch, so it is a watch worth considering for those who dream of the ultimate one-watch collection. Even if the movement's exterior is not at the level of tens of millions of won, it has a beauty that matches the price.

Of course, the fact that it is equipped with an innovative engine that other companies have not been able to do is a more important advantage than the appearance. This is a watch that makes me want to add Spring Drive to my collection someday. Some might say that the bracelet is still a weakness, but this time, the lightness and comfort of the titanium material offset the weakness. In short, I strongly recommend it. I hope these information has been useful to you. Thank you for watching. It is SangHwal Watches channel, and I'm the host SangHwal Kim. English subtitle - Seokmin Ko (M.D. SangHwal)

그랜드세이코의 풀티타늄 신상 SBGA415와 함께 알아보는 기술 혁신의 총체 '스프링 드라이브'의 모든 것!

그랜드세이코의 풀티타늄 신상 SBGA415와 함께 알아보는 기술 혁신의 총체 '스프링 드라이브'의 모든 것!