For most classic cars, the splined hubs on English and Italian cars are mechanically the same because they both follow the Rudge-Whitworth standard.
The wire-wheel world was dominated by the Rudge-Whitworth design (patented in the early 1900s), which was so successful that it became the universal standard for both English manufacturers and Italian ones (like Borrani).
The Shared Standards
The hubs are categorized by "Type" numbers, which refer to the maximum size of the outer bearing (in millimeters).
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Type 42 (Small/Medium): Found on British cars like the MG MGB, Austin-Healey, and Triumph, as well as Italian cars like the Alfa Romeo Giulia or Giulietta.
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Type 52 (Large): Found on high-performance British cars like the Jaguar E-Type and Aston Martin, as well as Italian exotics like Ferraris, Maseratis, and Lamborghinis.
Key Similarities & Differences
| Feature | British (Dunlop Style) | Italian (Borrani Style) |
| Spline Design | 60-degree V-shape | 60-degree V-shape |
| Thread Pitch | 8 TPI (Threads Per Inch) | 8 TPI (Standard Rudge) |
| Thread Direction | Self-tightening (LH on Right side) | Self-tightening (LH on Right side) |
| Cone Seat | 60-degree internal seat | 60-degree internal seat |
| Metric Exception | Very rare | Some rare models use 2.0mm pitch |
Are they interchangeable?
While the splined interface is the same, you cannot always swap wheels between the two:
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Thread Pitch Exceptions: While most Italian Borrani hubs use the standard 8 TPI thread, a few rare Italian marques experimented with metric thread pitches (like 2.00mm). If you try to force a British knock-off onto a metric Italian hub, you will strip the threads.
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Hub Length: Both types come in "short" and "long" (standard) versions. A wheel designed for a long hub will not seat properly on a short hub, even if the splines match.
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Offset and Clearance: Even if the wheel fits the hub, it may rub against the brake calipers or fenders. Italian Borrani wheels often have different "backspacing" than British Dunlop wheels.
We are happy to look up the specific hub size and spline count for the car you're working on, and find an appropriate hub/wheel match. We have worked with many "non-British" classic car owners.
