Now that is a massively bold statement to make… here it is again just to make sure that I did actually say it… “The most comprehensive resource available for frames built at the Specialist Bicycle Development Unit (SBDU)…”
This post isn’t necessarily about the SBDU, but I thought I’d write it as I get asked regularly to confirm seat pin sizes, or to try and decipher what an SBDU frame might be made from based on the seat pin and tube size. After collecting several SB frames over the years, I’ve seen lots of different seat pin sizes used in Reynolds frames. I have seat pins ranging from 26.6 to 27.4 – and 753 frames with 4 different size pins. That demonstrates just how varied their tube gauges were. So here is a little post that lists some of the most common seat pin sizes and the associated Reynolds tube gauge (wall thickness).
The search terms used by people who reach my blog are often connected to searching for information about the weight of a frame, specifically Reynolds 753 and Reynolds 531. So I thought I would write a little post to show the weight information I’ve collected on my own frames. I have frame weight data on several SBDU frames across a range of Reynolds tube sets. What I’ve found is that it isn’t simply a case of saying that every 57cm Reynolds 531 frame will weigh the same. Lots of factors influence frame weight.
I’ve wanted to write this post for a while, and I’ve tried to start and structure it a few times, but it has been difficult getting to grips with the scale of the subject. There was often either too much conflicting information or sometimes a complete lack of information about Reynolds tubes. Hopefully I’ve got a good grasp now, although it has still taken longer than expected to get all of this out of my head and crammed into a short, informative and hopefully coherent blog post.
Frame details…, it is all about those little frame details… Frame details are hard to change. They are individual elements, fitted to tubes and formed into a frame when the torch melts the filler. Paint and decals are not the same, they can change over time, fooling you and misleading you with a different story… the frame detail should always tell the real story.
The SBDU at Ilkeston used a range of different frame and fork details over the life of the unit. The amount of different details they used means that this post may turn into an epic. I did consider splitting it into 2 smaller posts, pre and post 1980, but as this is ultimately a timeline post, I wanted it to be unbroken, and to start and complete in one go. Hopefully, it will be helpful for anyone doing research into their own SBDU frame. I’ll also try my best to fit dates and years in as I go. If you are a fan of the SBDU or simply need to know these details, then please stick with me. I learnt so much while researching and writing this post, hopefully I can pass this information on to whoever wants to read further!