Grand Seiko · Spring Drive

Strap for Spring Drive Stainless Steel / Black / Bracelet

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter41 mm
ReferenceSBGA101
FamilySpring Drive
MovementGrand Seiko caliber 9R65 Hours, Minutes, Seconds | Date | Power Reserve Indicator
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Spring Drive SBGA101

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Spring Drive SBGA101, seen from the bench

The Grand Seiko Spring Drive SBGA101 features the 9R65 caliber, a hybrid movement that combines traditional mechanics and quartz regulation. The mechanism offers hour, minute, second, date and power reserve indications. The Spring Drive technology ensures an accuracy of ±1 second per month through the electronic control of the mechanical oscillator.

Frequently asked questions

What is the exact lug width of the Grand Seiko Spring Drive SBGA101?

The lug width of the Grand Seiko SBGA101 is 20 millimetres. This dimension is critical for aftermarket strap compatibility. To verify it directly on your watch, use a digital calliper and measure the external distance between the two spring bars (the small metal rings anchoring the strap). A 22mm or 18mm strap will not fit correctly.

Which strap material is recommended for the Grand Seiko SBGA101?

Alligator remains the most sophisticated choice due to its natural three-dimensional grain pattern. For those seeking patina development over time, vegetable-tanned leather is ideal. If you prefer everyday versatility, a jacquard NATO strap or structured high-density rubber offer comfort and practicality. Shell cordovan in mahogany is the premium alternative that develops a fascinating patina.

How do you change the strap on the Grand Seiko SBGA101?

The change is straightforward and requires a spring bar tool or fine-tipped pen. Position the watch face-down on a table. Insert the tool under the spring bar from one side and lift gently until the bar extracts from its seat. Repeat on the other side. Insert the new strap by sliding the bars into both lugs sequentially, ensuring they are fully seated on both sides.

Can I use a non-official aftermarket strap on the Grand Seiko SBGA101?

Yes, provided the lug width is certified at 20mm and the spring bars are compatible (standard 20mm gauge). Milano Straps offers artisanal aftermarket straps in leather, alligator and shell cordovan, specifically constructed for this measurement. Always verify compatibility with the vendor before purchase to avoid disappointment.

How long does a leather strap last on a watch like the Grand Seiko SBGA101?

A quality leather strap (alligator, calf, shell cordovan) typically lasts 2–4 years with daily wear, provided it is maintained in a dry environment. Vegetable-tanned leather can last longer due to its density. Factors such as direct sunlight exposure, constant humidity and perspiration accelerate ageing. A NATO fabric strap lasts 3–5 years. Casati Milano offers an 18-month warranty on its artisanal straps.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only