Updated 20th March 2026

Reference & Identification Hub

The Archive’s primary technical resource for Western States Imports (WSI) era Diamond Back BMX frames (1979–1984).

Accurate identification of a vintage Diamond Back requires a combination of serial number decoding and physical characteristic verification. Over the last 20 years, we have categorized the evolution of these frames into two distinct research areas:

1. Interactive Serial Number Decoder

If you have a serial number stamped on your bottom bracket or dropout, use our interactive tool. The decoder identifies the production month, year, and manufacturing origin (such as Jere or Koizumi) based on established fabricator alphanumeric logic. It will also include at some point Centurion models such as the US Moto-1 and European/AUS equivalent Pro-Star range

Go to Interactive Decoder Tool

2. Technical Specifications & Geometry

Serial numbers tell you when a frame was fabricated, but the physical markers don't always tell you what model it is. Use our master specification table to cross-reference your frame's geometry and hardware.

Key Identifiers included in the Master Table:

Dropout Thickness: The critical 2mm vs. 3mm distinction between Race and Street models.

Seat Tube Angles: Noting the shift between Relaxed (1979), Layback to Near Vertical (1982) but this depends on the model.

Frame Features: Verification of Looptails, Euro vs. US Bottom Brackets, and Gusset evolutions.

View Technical Specifications Table

Why Accuracy Matters

During the rapid growth of the early 1980s, Diamond Back models often overlapped in production windows. A "1982" serial number could belong to a Silver Streak, a Pro Senior, or a Harry Leary Turbo. Fabrication dates didn't always refer to the year you received your bike because it took time for them to arrive at your dstination and very different to today shipping methods. By using both the decoder and the technical table, you can ensure your restoration or identification is historically accurate.