Blog General Topic SBDU Ilkeston SBDU Nottingham

SBDU Rarity – Can Adding Some Context Correct Common Perceptions

What would you consider rare about the Specialist Bicycle Development Unit (SBDU)? I’ve heard people say that SBDU Reynolds 753 frames are rare… are they, or is that just perception? Defining something as rare really has to be done carefully, and in relation to the context of the subject. The way things are perceived is not always the way things actually are. 

The Oxford English Dictionary definition of ‘rare’ is ” …(of a thing) not found in large numbers and so of interest or value…”. So does the definition of rare apply to SBDU frames? In the context of all the hundreds of thousands of handmade frames ever produced across the world then I guess SBDU frames are rare, they fit the definition. Even if you change the context and just look at British handmade frames, the 10,000’ish SBDU frames produced at Ilkeston and Nottingham are still considered rare. If you change the context again and look at the number of SBDU frames for sale across the world, they are rare. If you just look at Europe then they are less rare, and if you only look at the UK they are less rare again as there is a higher concentration of frames.

To fully understand the way something is regarded or perceived as rare, you would need to have some context of the topic. Without that context, a person’s perception can easily be wrong. Before looking at a specific type of SBDU frame later in this post, I want to start by looking at a much broader subject area. Let’s look at Reynolds 753 SB frames.

I said earlier that I often hear people saying that SBDU 753 frames are more rare than 531. Is that true or is it just perception? SB numbered 753 frames came along at the end of 1975, somewhere close to the SB500 point, and due to orders and delivery times, they probably became more prevalent from early 1976 at approx SB576. So that is my starting point for looking into this particular topic. Now let’s just look at Ilkeston built Reynolds 753 frames, that period ended at approx SB8400 – setting my upper limit on the topic. From SB576 to SB8400 what was the most rare SB frame tubing, 753 or 531?

TI-Reynolds Tubing Decals
TI-Reynolds Tubing Decals

I can only attempt to answer this based on the known information I have. Nobody has the full information on these 8000 frames, but I have a sample dataset covering a good range of each year from 1975 to 1986, totalling almost 500 frames. Here are the results after looking at these 500 frames…

  • Reynolds 753 (either 753, 753R or 753T) = 61%
  • Reynolds 531 (either 531DB, 531SL, 531P or 531c) = 32%
  • Unknown tubing = 7%

This shows you that based on this sample of data, just under two thirds of the SBDU frames made in that period were built with Reynolds 753. You could therefore say that Reynolds 531 was the more rare tube and 753 SBDU frames were much more common.

If you really want a rare frame then 531 Special Lightweight (531 SL) is the one to look out for. 531SL and 531 Professional have a combined total of only 8%, with only 2% of the total made up from 531SL. The SL tube was introduced at the same time as Reynolds 753 and I really think it was lost in all the WOW and excitement for the 753 transfer.

So the perception that Reynolds 753 has a greater rarity was probably based on the reasons that it was seen as the more exotic tube and was definately the more expensive, but when you look at it within context, that perception that it was more rare than 531 is clearly wrong.

Now here is what I really wanted to get at. I regularly hear that chromed Raleigh SBDU frames are rare. Are they rare or is it just that the context is not understood, meaning that the perception is wrong? So lets build up some context around these chrome frames.

SBDU SB7219 531 Pro Rear Stays
SBDU SB7219 531 Pro Rear Stays

Chrome had been offered on SBDU frames since the beginning in 1974 but it only extended to part or full fork blades and crowns. It lost a bit of popularity when 753 was introduced. This was because the SBDU would not chrome 753 and the TI-Raleigh paint scheme on these 753 frames had a solid red painted fork. The 531 TI-Raleigh frames soon followed suit and chrome fell out of fashion on these frames by 1977.

But chrome really seemed to kick back in around 1983 with the introduction of the 531 Professional ‘Super’ model using Reynolds 531 Professional tubing. These were offered with part chrome forks with the top of the blades painted to match the main frame colour. Later in 1983 and the start of 1984, the SBDU offered a full chrome frame. They went further and offered part chrome forks and part chrome stays together with the option of full chrome. My SB7219 from early 1985 is an example of the part chrome 531 Pro Super.

SBDU SB7219 Reynolds 531 Professional
SBDU SB7219 Reynolds 531 Professional

It was 1985 when the full chrome finish really took off in popularity as it was offered on lots more 531c frame models, not just 531P. This next image is from the 1985 Raleigh catalogue and shows a part chrome and full chrome 531 Pro Super.

Raleigh SBDU Custom Built Framesets 1985
Raleigh SBDU Custom Built Framesets 1985

Most of the 531c chromed frames in 1985 were Services des Courses (SDC), built with Cinelli lugs and side attached seat stays. 531 Pro Super frames used Prugnat lugs and Haden bottom bracket shells and typically had the fastback seat stay arrangement. The full chrome and team livery option is shown on the bottom frame in the catalogue image above. Sometimes the scheme differed slightly and some also had a painted BB shell and painted head lugs.

Lets apply some context to these 1985 frames and see if the perception of rarity is correct. The SBDU would not chrome 753 so the only tubing that could be chromed was 531c and 531P. I’ve actually looked at frames all the way through the SB7000 range – this range extends from the start of 1985 to maybe Easter 1986. Here are the results…

  • Of all the 753/531c/531P frames in the SB7000 range, 24% were chromed
  • Of the 531c/531P frames in the same dataset, 47% were fully chromed

These percentages show that during this period and regardless of tubing type, one in four frames had the full chrome/team livery finish, 24% is quite high. If you change the context and only look at the frames that the SBDU would consider for chrome plate, then 47% of these had the full chrome/team livery finish. Out of the 8400 Ilkeston frames you would be correct to say that not many were full chrome, so in that context the perception people hold that they are rare is true. However, when you add the missing context, and look at the period that the full chrome was offered, nearly every other frame that was eligible for chrome was chromed. In the proper context, these frames aren’t rare and the perception is wrong.

To summarise, some SBDU frames with certain features may be rare. French threaded SBDU frames are rare, they were offered but I’ve never seen one. SBDU Cyclo Cross frames are rare, I’ve only seen half a dozen even though they were always offered. Some early frame numbers are rare. 531SL frames are quite rare. The Dynaflite or any of the SBDU frames made from non round Reynolds tubing are rare. Some features like the Capella lugs, Haden crowns, Simplex ends and fittings are rare. But SB numbered 753 frames built with the tubing that the SBDU are most famous for are not rare SBDU frames. Chromed SB frames are not rare, they were really popular in their time. I guess what I am waffling on about is that you cannot say something is rare without understanding the circumstances and context around it. Just because someone says something is rare does not mean it is.

** My data and statistics are based on a sample set of the 8400 SBDU frames covering 1974 to 1987 and a small margin of error will apply**

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

2023 Xmas Offer

£15 Off

* available for boxed, 2 wheel, cable operated bicycles (non electric). Assembled at your home, depending on distance.

%d bloggers like this: