After working out that SB664 was built from an early type of Imperial Reynolds 753 tubing, I wanted to use the calipers and metal rule again to try and figure out what type of use the frame was built for. Was the geometry designed specifically for Road or Time Trial; the outward appearance such as the frame transfers suggest that it is probably an SBDU Time Trial frame. SB664 is an early SB numbered 753 frame and was probably ordered in first part 1976 or even in late 1975. Reynolds 753 was brand new, it had only just been shown to the public in trade shows and it wasn’t widely available outside of the TI-Raleigh team. So what was this frame designed to be?
In the beginning there was Metric Reynolds 753 tubing, and then later in 1982, a new Imperial Reynolds 753 tube was introduced. The new tube, called 753R, had different diameters, different gauges and was slightly heavier than the original Metric tube. And that’s how it was always known… Metric 753 before 1982 and Imperial 753 available after 1982. That seems quite straightforward doesn’t it?
There is no long winded waffle from me on this post, at least that is the intention… it’s hopefully just a short introduction about a new addition to the collection. There WILL be many more posts about this frame; this frame could fill my blog with new content for an entire year. It has some rather special and unique combinations of features that I have not seen on any other Specialist Bicycle Development Unit (SBDU) frame.