MB&F · Special Projects

Strap for SP One Red Gold

Takes 18 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width18 mm
Case diameter38 mm
ReferenceSP1.RL.B
FamilySpecial Projects
MovementMB&F caliber SP One Hours, Minutes
CaseRed Gold

Spring bar

Swiss Standard universal spring bars

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

Straps for the Special Projects SP1.RL.B

Selected for the 18 mm lug width · workshop selection

All 18 mm straps →

The Special Projects SP1.RL.B, seen from the bench

The MB&F Special Projects SP1.RL.B is a contemporary watchmaking experiment with a 38mm red gold case and MB&F SP One calibre movement displaying hours and minutes. This model features an 18mm lug width, an uncommon dimension that demands precise craftsmanship for proper strap integration. The red gold case develops a unique patina over time, while the 38mm diameter balances presence with wearability on the wrist.

Frequently asked questions

What is the lug width of the MB&F Special Projects SP1.RL.B?

The lug width of the MB&F Special Projects SP1.RL.B is 18mm. This non-standard dimension requires a specific strap, measured from the inner shoulder of one spring bar to the other. At milanostraps.it, you will find a dedicated collection of 18mm straps compatible with this model.

What is the best strap for the MB&F Special Projects SP1.RL.B?

The best strap depends on your usage and aesthetic preferences. For formal elegance, we recommend alligator in cognac tones or vegetable-tanned calf leather. For a contemporary approach, a charcoal-grey NATO textile strap enhances the radical geometry of the case. For durability and versatility, high-quality rubber is ideal. Your choice should reflect the design philosophy of the watch.

How do you change the strap on an MB&F Special Projects?

Strap replacement is accomplished using the spring bars (pressure springs) located at the ansa extremities. Use a dedicated tool (spring bar tool) to compress the spring and slide out the old strap. Position the new strap, aligning the holes with the spring bars, and release: the spring will click into place. For watches of the value of the SP1.RL.B, we recommend having the operation performed by an expert.

Are aftermarket straps compatible with the MB&F Special Projects SP1.RL.B?

Yes, any strap with an 18mm lug width is compatible. However, the construction quality must be superior to honour the design level of the watch. We recommend specialised artisans such as milanostraps.it, who offer certified leather, precise stitching and refined finishes, ensuring compatibility and durability over time.

How long does a leather strap last on an MB&F Special Projects?

A premium leather strap, used daily, typically lasts 3-5 years before requiring maintenance or replacement. Factors such as sun exposure, humidity and intensity of use affect longevity. Vegetable tanning is more robust and resistant to ageing than alligator leather. With proper care and rotation between multiple straps, the useful life extends significantly.

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.

Request an appointment →

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