Seiko SARB017 vs SPB121: Which is the Superior Alpinist?

If you’re a Seiko fan or even just a casual watch lover, chances are you’ve heard of the Seiko Alpinist. This also means you’ve probably heard of, or at least seen in passing, either the Seiko Alpinist SARB017 or SPB121. With their green dials, golden accents, and signature internal compass bezels, these two models have become, for many collectors, the flagship Alpinist. 

But yes, these are two gateway watches that look almost identical. They are two very similar versions of the Alpinist, so understandably, many of us struggle to comprehend the differences between them, which makes it hard to pick between the two when it comes to purchasing one for our own wrists. 

But alas, there are a few differences to note. While the Seiko Alpinist SARB017 is the oldest of the two, and now sadly discontinued, the SPB121 is still holding strong in Seiko’s lineup.

You might have also spotted a few tweaks to the case dimensions, movement, and case back décor. These might not seem like big differences, but as any watch collector will argue, these small details can make all the difference. 

So, to help you decide between the Seiko Alpinist SARB017 and SPB121, let’s take a look at what each of these watches have to offer.

Why the Seiko Alpinist in the First Place? 

Seiko is probably best known for their diving watches, otherwise known as the Prospex collection, or their luxury sister company Grand Seiko. However, another family considered a big deal, especially with collectors who appreciate retro design, is the Seiko Alpinist. 

It’s a watch that debuted in 1961 and made history as Seiko’s first-ever “sports watch.” It was designed to be a rugged, reliable timepiece that could withstand the harsh conditions faced by mountain climbers in Japan. It had to be tough, legible, and ready to handle the great outdoors. 

The original Alpinist, named the Seiko Laurel, was a true milestone for the brand. It featured the now-iconic arrow markers at 12, 3, 6, and 9, and was available in black and cream dials. In the watch-collecting world, these inaugural versions are considered the holy grails of Alpinists. 

Fast forward to today, and the Alpinist has evolved into one of Seiko’s most beloved models. Its popularity skyrocketed with the release of the SARB017 (yes, one of the models we’re looking at today), which became a collector’s favorite before it was discontinued. 

Other modern-day models like the Baby Alpinist have also proved the collection’s popularity. Truthfully, the Alpinist, in all its forms, deserves a place in any collector’s watch box, but as I’m sure you’ve realized by now, the Seiko SARB017 and SPB121 are two of the most coveted – and for good reason.

The Seiko SARB017

Aside from the Seiko Laurel, the Alpinist SARB017 might just be one of the most important designs to join the explorer-inspired line-up. Released in 2006 as part of the brand’s SARB series, this model represented the fifth generation of the Alpinist. 

Its release came at the perfect time when the watch enthusiast community was beginning to grow, and the SARB017 quickly became a favorite of collectors worldwide. 

One of the most notable features of the SARB017 is its stunning sunburst emerald green dial. This striking color, complemented by gold-plated Arabic numerals and dagger-shaped hour markers, gave the watch a distinct and refined look that set it apart from other models. 

The gold accents paired beautifully with the brown alligator-textured leather strap, creating a watch that was both rugged and elegant. The dial also features elegant cathedral-style hands and a date window at 3 o’clock. 

Another notable feature of the SARB017 was its internal rotating compass bezel. This unique feature, combined with the watch’s legible dial and durable 38mm stainless steel case, made it a versatile piece that could easily transition from outdoor adventures to more formal settings. 

The rotating bezel, which could be adjusted with a second crown at 4 o’clock, gave the watch a functional yet subtle flair, tucking neatly into the design without overwhelming it.

The design also boasted the brand’s in-house Caliber 6R15 mechanical movement, which offered an impressive 23 jewels and a 50-hour power reserve. 

Although the SARB017 was initially a Japan Domestic Model (JDM) release, making it difficult to find outside Japan, its allure only grew as word spread.

The SARB017 became a sought-after “forbidden fruit” for collectors around the world. Its limited availability, combined with its stunning design and functionality, created a sense of exclusivity that fuelled its growing demand.

The Seiko SPB121

For the newer Seiko Alpinist SPB121, I almost think of this novelty as a love letter to the SARB017. It’s clearly designed with the same core appeal but updated with a few thoughtful tweaks.

Seiko recognized the SARB017’s massive fanbase and how coveted it became after its discontinuation, so they essentially took everything collectors loved about the Alpinist and gave it a modern refresh. 

The green sunburst dial is back, just as striking as before, along with the signature gold-plated hour markers and hands that give the watch its distinct character. The rotating internal bezel also makes a return, as does the classic brown leather strap, making the SPB121 feel like an evolution of the iconic SARB017.

While the design closely mirrors its predecessor, there are some key changes that make the SPB121 a little different. For one, the case has grown ever so slightly, from 38mm to 39.5mm, making it feel a bit more substantial on the wrist. 

The thickness has also increased from 12mm to 13.2mm, adding a more solid presence, which further adds to the Alpinist’s rugged elegance.

Another noticeable upgrade is the exhibition case back, giving owners a clear view of the new movement inside Seiko’s in-house Calibre 6R35. This movement offers a substantial boost in power reserve, now clocking in at 70 hours compared to the 6R15’s 50-hour reserve. 

There are also some other subtle tweaks on the dial, like the slightly redesigned dial text and the reintroduction of the cyclops date magnifier. The Prospex “X” logo replaces the previous Diashock branding to mark the model’s new home in Seiko’s dive watch line. 

Despite these upgrades, the SPB121 maintains the soul of the SARB017, offering collectors the same style and functionality that made the original such a hit. Of course, these enhancements come with a slightly higher price tag. The newest model retails for around $725 new, compared to the $700 launch price of the SARB017. 

However, considering that the SARB017 now regularly fetches upwards of $1,000 on the second-hand market, the SPB121 represents a more accessible way to get your hands on a modern Alpinist, while still enjoying all the nostalgic charm of the original.

Seiko SARB017 vs SPB121 – How to Choose 

When deciding between the Seiko SARB017 and the Seiko SPB121, there are a few important factors to consider that will help you determine which model suits you best. Both watches share a common heritage, with the SPB121 being a direct successor to the SARB017, but there are enough differences to make each model unique, and appealing to different types of collectors. 

The Case Size and Fit 

One of the first things you’ll notice when comparing the two watches is their size. The Seiko SARB017 comes with a 38mm case diameter, while the SPB121 is slightly larger at 39.5mm. 

For those with smaller wrists, or those who simply prefer a more compact watch, the SARB017’s 38mm case might be the better fit. It’s a classic size that maintains the Alpinist’s rugged yet elegant look without feeling too bulky. Additionally, the SARB017’s slimmer 12mm thickness makes it comfortable and unobtrusive on the wrist. 

On the other hand, if you have larger wrists or prefer a more substantial watch, the SPB121 might be a better choice. The 39.5mm case diameter, coupled with the slightly increased thickness of 13.2mm, gives the SPB121 a more robust presence. The larger case size also makes the SPB121 a bit more modern in feel, while still retaining the Alpinist’s charm. 

Movement and Power Reserve 

Another significant difference between these two watches is their movements. The SARB017 uses Seiko’s 6R15 automatic movement, which has been a reliable and well-loved workhorse in the world of affordable mechanical watches. 

However, the movement offers a power reserve of 50 hours, which is great for daily wear but might fall short if you’re someone who tends to rotate watches over the weekend and leave one off for a few days at a time. 

The SPB121, on the other hand, is powered by the newer Seiko 6R35 movement. This movement offers a notable improvement with a 70-hour power reserve, meaning that it can last through an entire weekend without needing to be wound. 

For those who like to take a break from wearing their watch on the weekends and don’t want to worry about winding it up again, this increased power reserve is a clear advantage. Plus, the SPB121’s 6R35 movement is slightly more refined and updated compared to the 6R15, making it an attractive choice for those seeking a more modern technical upgrade. 

Additionally, the SPB121 comes with an exhibition case back, which allows you to admire the movement in all its mechanical glory. This is a welcome touch for many watch wearers who appreciate seeing the inner workings of their timepieces. 

The SARB017, however, keeps things more classic with a solid stainless steel case back that features the Alpinist logo. While it may not have the same “show-off” quality as the SPB121, the SARB017’s case back is part of its vintage charm and speaks to the history and heritage of the model. 

Dial Design 

When it comes to the dial, the SPB121 stays remarkably true to the SARB017’s iconic green sunburst dial. The color remains the same, with the gold-plated hour markers and hands that give the watch its distinct character. 

However, there are some refinements in the SPB121, including a cleaner dial with less text and the reintroduction of the cyclops date magnifier at 3 o’clock, which gives the dial a slightly more contemporary look. 

The SARB017, on the other hand, has the original Alpinist logo and a slightly more vintage feel with its classic design and cluttered dial text.

Much of this is down to the lettering detailing its Diashock movement. It might not be an important thing to denote for some of you, but it does give it that nostalgic allure that the SPB121, despite its many strengths, can’t quite replicate. 

Which One Is Right for You? 

If you’re after a more modern take on the classic Alpinist, the SPB121 is likely the better choice. With its larger case, upgraded movement, exhibition case back, and improved power reserve, it offers a more contemporary experience without straying too far from the original design that made the SARB017 so beloved. 

However, if you’re someone who appreciates the vintage feel and charm of the original Alpinist, the SARB017 is going to appeal more. It’s more compact, offers a classic design, and carries with it the weight of Seiko’s rich history. 

If you already own the SARB017, you might also be asking if upgrading to the SPB121 is worth it. For myself, and I’m sure many others, too, the answer is no.  While the SPB121 does bring some meaningful improvements, the SARB017 still offers incredible value and remains a classic in its own right.

Conclusion

In the end, choosing between the Seiko SARB017 and the SPB121 comes down to your personal preferences.

If you’re after a more substantial, modern watch with a longer power reserve, a slightly larger case, and a refined design, the SPB121 is the way to go. However, if you’re drawn to Seiko’s rich history, a more compact size, and vintage-inspired look, the SARB017 will be your favorite. 

Honestly, though, you can’t go wrong with either model. Both watches offer outstanding storytelling, impressive technology, and exceptional design at a great price.

So whether you leave here to shop a pre-owned SARB017 on the second-hand market or go for a brand-new SPB121 from your local authorized Seiko retailer like Exquisite Timepieces, I promise you won’t be disappointed with your choice.