When did the Specialist Bicycle Development Unit (SBDU) at Ilkeston close and relocate to Nottingham? What frame number were they up to at that time? Those are just two of the many questions that surround this seemingly mysterious unit. I’ve been searching for the answer to these questions for as long as I’ve been researching the unit. Late last night, a friend sent me a link to an SBDU bike that may finally answer at least one or maybe both of those two questions.
I’m sure that one day, some actual Ilkeston records will surface that will explain all, but at the moment, there is nothing. Last year I put a lot of effort into producing an SBDU date timeline, but even at the end of all that research, I couldn’t get the range of SB frame numbers marking the end period of Ilkeston production to less than 254 frames (SB8367 – SB8621). Then at the start of 2017, a frame popped onto my radar that brought this range down to 71 frames (SB8367 – SB8438).
Just to recap, I’m using original paint / original transfer frames to identify this period, and the key feature of these frames that I’m looking at is the text in the SBDU oval… Now this is only my theory, and I am careful to make sure that as far as I can verify, these frames are 100% original with original transfers. This is the only feature I’ve been able to find that may differentiate the two SBDU locations. A better method may come along in the future, but this is all I have to work on at the moment.

Ilkeston period frames would use ‘ILKESTON’ on that oval transfer, but my theory evolved as some of the frames I was discovering didn’t have that wording, the red band section was left blank. All these blank transfers were on frames from the mid SB8600s, and must, in my opinion, be that way because they were built at SBDU Nottingham.
The first frame I noticed with this feature was SB8621. I had a huge 254 frame gap in my data, so my theory at that moment was that Ilkeston closed and relocated at some point between SB8367 (which was the last frame in my data in original paint that has ‘ILKESTON’ on the transfer) and SB8621 (which was the first frame in my data in original paint that did not have ‘ILKESTON’ on the transfer).
Then SB8438 came along – without ILKESTON, with a blank red section…

After talking with the owner, the story he gave tied in with this frame having original paint and transfers. This was good information and brought that 254 frame period down to 71 (SB8367 – SB8438).
So it was great that I was able to narrow down the amount of frames marking the closure of Ilkeston to within 71 frames, but that still didn’t help answer the question of when it relocated. The SB numbers in that 71 frame range were indicating a build date at some time at the end of 1986 or the beginning of 1987. The Raleigh literature of the period didn’t help either. I have SBDU leaflets from the 86/87 period that show both SBDU Ilkeston and SBDU Nottingham, but the only dated leaflet is the one on the right, SBDU Nottingham, dated October 1987 – these didn’t help to narrow down the time period.

However, last night, just before deciding to go to bed, a message pinged into my Messenger inbox (thank you Robert!) with a link to an SBDU frame, but with a message about a totally unrelated SBDU topic. I took the iPad to bed and did a little bit of bed time reading.
The frame discussed in the link was SB8422 and it was in original paint and had comments on the thread from the original owner who ordered the frame in 1986. This frame had three significant features…
- It was original paint – confirmed by the original owner
- It had ‘ILKESTON’ on the chain stay transfer
- It was double stamped, meaning that not only did it have an SB number, it also had stampings giving some initials and the year – that year was 1986.
Hopefully at this point in the post you are keeping up with me; I do tend to waffle when I’m frantically trying to type out all these random thoughts in my head before I forget them!
The SBDU were known on occasion to stamp owners initials onto the BB in the same format as Raleigh’s famous team riders (Initials . frame no . Year). In my date timeline, I have the start of 1986 identified by two of these double stamped frames. SB7831 and SB7870 which are both also stamped with ’86’. I own SB7657 which I know was built very late 1985, and I used a point between SB7657 and SB7831 to define the start of 1986 as SB7701.
The long held common belief is that Ilkeston closed at approx frame number SB84xx and my discoveries last year were definately starting to point towards this being correct. You can’t really pinpoint exactly how many frames the SBDU built each year but they seemed to produce more frames in the late 70s / early 80s. By the time 84/85/86 came along, I think the average was about 700 frames each year. Therefore, if you take this average figure of 700 and add that to SB7701, you should end up with one years worth of production, taking you to the end of 1986… SB7701 + 700 = SB8401. That calculation probably explains where the SB84xx story has come from.
Getting back to last night’s discovery of SB8422 with ILKESTON on the transfer. This may mean that it is one of the very last frames produced at Ilkeston and the SB number tallies with this being right at the turn of the year between 1986 and 1987. Therefore, the gap – or the period of relocation has been reduced to only 16 frames (SB8422 – SB8438).
I’m now more confident than ever that the SBDU relocated from Ilkeston to Nottingham at some point at the turn of the year between 1986 and 1987 when frame number production was between SB8422 and SB8438. When different people talk about the closure of Ilkeston, some refer to 1986 and some refer to 1987; maybe it is because it happened at the turn of the year – you could describe the end of 1986 as the start of 1987, one and the same thing isn’t it?
I now have an Ilkeston date timeline that looks like this…
1974 - Start SB1 End SB50 1975 - Start SB51 End SB500 1976 - Start SB501 End SB1010 1977 - Start SB1011 End SB1870 1978 - Start SB1871 End SB2600 1979 - Start SB2601 End SB3400 1980 - Start SB3401 End SB4200 1981 - Start SB4201 End SB4900 1982 - Start SB4901 End SB5650 1983 - Start SB5651 End SB6300 1984 - Start SB6301 End SB7000 1985 - Start SB7001 End SB7700 1986 - Start SB7701 End SB8430 1987 - Start SB8431 End SB8432 - SB8438... SB Frame Production relocated to Nottingham
Someone somewhere must have some paperwork, some form of Raleigh document that discusses this relocation. Maybe one day I’ll find it and I’ll eventually be able to get that elusive closure date…
This is great, love your attention to detail. I have been enjoying reading your posts for about 6 months and used your info to identify that a resprayed sbdu frame with 753r decals that I bought was in fact made with metric 753 tubing. Keep it coming.
Thank you. I’m glad my data is helping. One of the initial reasons for my blog was to fill the gaps that I found when I was building my first SB. I’m really pleased that others are finding it useful.
Cheers
Neil