This isn’t intended to be an Internet resource of Raleigh frame numbers! If you are reading this for anything other than SB number sequences from the SBDU then please make sure you corroborate my information with other resources.

This post covers the background of things I’ve learnt about Raleigh frame numbering systems during my own research over the last few years. It ranges from the late 60s, to the introduction of ‘W’ numbers at TI-Raleigh’s Worksop Carlton factory. Extending through to the late 1990s and Raleigh’s Special Products Division. The only numbers I’m confident about are the Specialist Bicycle Development Unit (SBDU) SB frame numbers at Ilkeston. Some of this blog post, especially the late 80s / early 90s is what I will call ‘work in progress – thinking out loud – still formulating things in my head‘ type of work, there just aren’t enough bikes available at the moment to provide more accurate detail.

Even though they are documented in other online sources, I’m including TI-Raleigh’s Worksop Carlton facility and the subsequent Nottingham Lightweight Unit in this post because of the numerous requests I receive for advice on dating these bikes. Although the explosion of social media has meant that there are numerous Facebook groups and internet forums where information is given, I often see this quite simple topic explained or interpreted incorrectly over and over again. There is even confusion about facilities such as Ilkeston/Worksop and the Lightweight Unit or the SBDU with Raleigh Special Products.

So I’ll start with the ‘W’ reference originating from Worksop. I’ll then move onto the SBDU ‘SB’ reference and then the Special Products system. I’ll also cover a little on ‘SBW’ numbers and ‘SC’ numbers.

1973: TI-Raleigh’s Worksop Carlton Facility and (1981) the Lightweight Unit at Nottingham

There are several sources for Worksop frame number information, but with every piece of information on the internet, the very first things you should ask yourself is… where does this information come from..? Who wrote it..? What is their experience and background..?  So much information is user generated and doesn’t come from original or confirmed sources.

These different sources have conflicting information regarding the actual period in which the ‘W’ reference started; while some say it was late 1973, others say 1974. My own opinion, after reading through so many articles and looking at not only the writings of the authors but also their own collections and experience, is to accept the late 1973 start date of the ‘W’ reference for Carlton/Raleigh frames as correct.

I say ‘accepted‘ a lot because so many things are actually unknown, and the actual start date in 1973 is one of many unknowns when it comes to the subject of frame numbers and Raleigh frame numbers especially. However, as time goes by and more information is seen, a fact with unknown provenance can become an accepted piece of data if it proves time and time again to be accurate. The 1973 start date, although not proven with any documentation as far as I am aware, seems to be an accurate piece of data, and because of this, it is becoming the accepted date.

The use of the ‘W’ reference appeared to end during 1989 – I’ll explain more about that later.

Worksop & Nottingham Lightweight Unit ‘W’ Number Format:

The format of the ‘W’ reference is broken down into 4 separate sections; and of those 4 sections, only 1 section is necessary to date these frames… I’ll use an example frame number of WD6000123 to explain these sections.

The ‘W’ reference was stamped reading across the BB shell from one face of the shell to the other.

The 4 separate sections of the frame number are…

1.  ‘W‘ – the first letter
2.  ‘D‘ – the second letter
3.  ‘6‘ – the first number
4.  ‘000123‘ – the six remaining numbers

The only section you need to date these frames is the first number (the third section of the frame number) – in the example I am using it is a ‘6‘, so it is this part of the frame number that I’ll start with.

[W] [D] [6] [000123]

There is only a single number from 0 to 9 to represent the year, therefore a single number will be repeated every 10 years. This system ran from 1973 to 1989 meaning that the ‘6’ can be either 1976 or 1986.

• ‘3’ = 1973/1983
• ‘4’ = 1974/1984
• ‘5’ = 1975/1985
• ‘6’ = 1976/1986
• ‘7’ = 1977/1987
• ‘8’ = 1978/1988
• ‘9’ = 1979/1989
• ‘0’ = 1980
• ‘1’ = 1981
• ‘2’ = 1982

If you have a ‘0’, a ‘1’ or a ‘2’ then that can only be 1980, 1981 or 1982 because this system did not run in the early 70s or early 90s.

To decide between the decades, you need to know a little about 1970s and 1980s bike design. In my mind there are lots of differences between a 1970s bike and a bike from the 1980s – a 1986 bike will look very different to a 1976 bike. Some of the features I look for to determine the difference between the 70s and 80s are…

• The routing of gear cables moved from above the BB shell to below; this is often a significant clue. This happened for most builders at some point during 1979/1980 which makes it the very first thing I check
• Another clue could be standard nutted brakes or later recessed allen key brakes
• If paint and transfers are original then Reynolds frame transfers for 531 frames can be used for dating, they were very different between the 70s and 80s. If you are unsure about the originality of the transfers then keep to physical frame features
• If the transfers are original then some model names may only have existed in certain years making the year identification easier
• Frame tubes such as seat stays and fork blades changed design so you may be able to spot an earlier single taper or later double taper seat stay or a narrow/wide oval fork blade
• 70s bikes may have used cable clips and band on gear levers. 80s bikes probably used braze on gear levers
• Some 70s bikes with braze on brake cable guides route the rear brake cable along the RH side of the top tube whereas most 80s bikes will route the cable along the top or LH side
• Rear OLN size on a 70s frame may be 120mm for 5 speed/compact 6 speed. A 1980s frame may be 126mm for 6/7 speed

These aren’t hard and fast rules of bike design but as you can see, there are a few things to look at, and one or more of these will help you spot the decade a bike was built.

NOTE: Physical bike frame features are much better to use for frame dating rather than paint and transfers. Even a good quality but old repaint can look original and cast doubt. Only use paint and transfers if you are 100% positive that they are original. Things like seat stays, fork ends, head lugs and fork crowns are by far the best features to use as they are much less likely to have been updated, even braze on fittings can be changed and updated over time. Be careful using components to date your frame; components can easily be replaced and give a false impression of the age of a bike.

As I said, this section of the frame number is ALL YOU NEED  to date a frame that uses this format.

[W] [D] [6] [000123]

The first letter of this numbering system will correspond to the location the frame was built. When the system started in 1973 the ‘W’ referenced Worksop. Other letters existed for other facilities and locations around the world. However, the ‘W’ is all I’m interested in here.

The Worksop facility closed in late May 1981 and a new ‘Lightweight Unit’ opened at Raleigh’s main Nottingham location in the October of the same year.

The Worksop Guardian published the following on Friday 29th May 1981…

“No more will the famous Carlton be made in Worksop.

Carlton Cycles, one of Worksop’s oldest factories, finally ground to a halt on Friday… TI Raleigh, the parent company, in Nottingham, decided some weeks ago to close the plant and give notice to the 202 employees.
On Friday the last batch of them – 50 from the production department – finally left… The Carlton name will not disappear. Machines bearing the famous name will be produced in a scaled down operation in Nottingham…”

The only thing to note is that the newly opened Lightweight Unit continued to use the ‘W’ prefix. In my opinion, this was to differentiate between the output of the new Lightweight Unit and the standard frames already produced at Nottingham and carrying the ‘N’ prefix. It is slightly confusing and has meant that some believe Worksop production extended past 1981.

The opening of the new Lightweight Unit was date referenced in a Spring 1982 Raleigh catalogue…

The opening was also reported in November 1981…

The continuation of the ‘W’ reference at the Lightweight Unit means that…

• Any ‘W’ frame dating between 1973 and 1980 is definitely Worksop
• Any ‘W’ frame dating from 1982 onward is definitely Nottingham’s Lightweight Unit

Therefore, if my example bike was built in 1976 it would have been made at Worksop. If it had been built in 1986 it would still have the ‘W’ prefix but would have been built at the Lightweight Unit.

This leaves those frames built in 1981, the year Worksop closed and the Lightweight Unit opened. A 1981 frame could be either Worksop or the Lightweight Unit depending on how far through the year it was built. If you really want to know which part of the year your frame was built and therefore, which unit produced it, then the 2nd letter of the frame number is meant to correspond to the month of production.

[W] [D] [6] [000123]

I personally don’t see the need to know which part of the year a frame was built. Most people who are seeking to date their frame will probably just need to know the year so that they can find the appropriate catalogue and see a period correct spec and colour scheme.

Some owners who have a 1981 ‘W’ reference bike (the year that production moved) may like to know if their frame was Worksop or Nottingham built. There are people who will rate a Worksop built frame over a Nottingham Lightweight Unit frame. The same thinking exists for some with Ilkeston SBDU and Nottingham SBDU. Worksop and Ilkeston are steeped in history and unfortunately Nottingham SBDU and Lightweight Unit frames seem to be placed in a lower class. From my experience though, especially with the SBDU frames, there is a similar build quality between the two locations of the SBDU. Likewise, of all the Nottingham Lightweight Unit frames I have seen have been of a comparable quality to Worksop.

Remember that a name is just a name, and anyone, even Ilkeston and Worksop can produce a bad frame. Also keep in mind that any ‘W’ reference frame regardless of which facility built it, was a frame built under TI-Raleigh’s ownership (TI-Raleigh acquired Carlton and therefore the Worksop production facility in 1960). If there really is a reason why you need to know more than the year a frame was built then the second section should help.

It is accepted that there were 12 letters used to denote each month. Note how I used that word ‘accepted‘ again. It is accepted because I have never seen a confirmed Raleigh endorsed, branded, coded or dated document. However, the 12 letters do seem to relate and therefore they have become accepted.

• A = January
• B = February
• D = March
• E = April
• G = May
• H = June
• K = July
• L = August
• M = September
• N = October
• P = November
• S = December

My example frame number would correspond to March production based on the accepted meaning of these letters.

So what are the last 6 numbers…

[W] [D] [6] [000123]

My best advice would be to ignore them. There are many different opinions about what they are meant to define.

The last six numbers are reported to relate to the amount of frames produced in a production period. But what exactly does that mean? What frames are covered in that period? What length of time is a production period?

Does it mean…

• the amount of a specific model produced in a month or year period?
• the amount of each and every model in a month or year period?
• the amount of frames produced in a certain production run – how long was a production run?
• the amount of frames produced per month at any location?

Because these numbers aren’t required for frame dating and because their meaning is not defined accurately in any Raleigh endorsed document, then ignore them, they are not required for frame dating.

To summarise the ‘W’ reference…

• The ‘W’ reference was introduced in late 1973
• The ‘W’ reference indicates Worksop built until May 1981
• The ‘W’ reference indicates Nottingham Lightweight Unit built from October 1981
• The 2nd letter is one of 12 assigned letters denoting the month of production
• The first number in the sequence is the year of production, repeated every 10 years between 1973 and 1989
• The last 6 numbers are reportedly a production number

A word of caution…

Several online resources contain errors or assumptions. Even the most used and shared ‘W’ reference information carries no official Raleigh endorsement, letterhead, reference, code or date.

Raleigh also made a lot of use of the term “Our policy of continual improvement means that product specification and appearance may be changed while this catalogue is still in use“, meaning that even once you have dated your frame, some Raleigh bikes, specifications and colours are really hard to trace through their own catalogues.

1974: Specialist Bicycle Development Unit (SBDU) Ilkeston

Throughout this whole post there is a definite trend of no actual Raleigh endorsed frame number information. There are no officially stamped and dated Raleigh documents or even any documents with a Raleigh letterhead that explain frame numbers. The SBDU is no different and there are no build records unless you are an owner who is lucky enough to have the original build and receipt documents for your frame.

There were a few existing attempts at timelines floating around the internet but they didn’t seem to have any fundamental backing to their facts, they were simply a multiplication of numbers per year. So I set about researching some facts that could help to identify the yearly boundaries between the sequential numbers that make up the SBDU frame number system. I used records of actual owner receipts together with knowledge of tubing spec changes and Reynolds transfer changes to identify a new timeline.

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

SBDU Ilkeston Number Format:

There are no hidden codes or sections in an SB frame number, there is no code for month of production or any indication of periodic production numbers – the SB number is just a sequential number starting from SB1.

The SB frame number was always stamped on the BB shell. It had a few different formats and locations on the BB especially in the first two years, but then settled in the region along the edge of the BB shell and often, but not always, had the corresponding number (without the SB prefix) on the fork column.

There were a few variations in the location of the SB reference, and there were sometimes other letters and references stamped on the BB and fork column which I’ll be covering soon in a new blog post.

It has been a few years since I wrote this timeline and it has so far stood up to every frame I’ve seen or been sent. For more information about the theory behind these yearly numbers you should read the full blog post here.

1987: Specialist Bicycle Development Unit (SBDU) Nottingham

I’ve never found any accurate information online about the specific date that the SBDU relocated from Ilkeston to Nottingham. The clue came when I started to see original paint frames with SBDU oval transfers that lacked the work ILKESTON on the transfer. Some resources mention the move in 1986 and some refer to 1987 and the way my timeline has worked out, it seems to have been the period between the two years, it could have been the end of 86 or the start of 87.

SBDU Nottingham Number Format:

The same ‘SB’ prefix for the SBDU frames from Ilkeston was retained and used at Nottingham; the numbers continued in sequence from the mid 8000s.

The SB frame number continued to be stamped along the edge of the BB shell and often, but not always, had the corresponding number (without the SB prefix) on the fork column.

There is a common misconception that the SBDU closed at the end of Ilkeston production whereas the SBDU didn’t close, it simply relocated. Times were changing in the custom steel frame building market, things were getting tough for lots of classic builders, my own shop stopped their own frame building in the late 1980s. Different materials were emerging and mail order was offering massive price savings; it was a few years since Raleigh had a major continental team, and if the SBDU were getting fewer orders, the misconception that they had closed their doors at Ilkeston certainly wouldn’t have helped.

The SBDU at Nottingham started as a separate unit to the existing Lightweight Unit which was created in 1981. Both units ran side by side and with a different remit to produce different frames.

Dating an SBDU Nottingham frame is difficult. This is because there are so few available example frames and even less with any kind of accurate dating evidence. What I do know for sure is that Nottingham production did not match the quantities that came out of Ilkeston. Nottingham production started well in 1987 but soon tailed off.

I’ll hopefully be able to put together a basic SBDU Nottingham timeline soon, it is something I’m currently researching.

This extract is a great source of information because it’s not only produced by and marked as Raleigh, it is also dated to October 1987. However, it shows that everyone can make mistakes and you should always fact check information, even officially endorsed information… the Panasonic frame in this leaflet is not a Services des Courses frame as indicated in the text; it appears to have a Prugnat seat lug and the fastback seat stay design.

At the moment based on bikes that I have viewed, my opinion is that the SBDU at Nottingham used frame numbers between (approx) SB8438 & SB9099.

1989/1990: Raleigh Special Products Division

If there was very little information about the ‘W’ and ‘SB’ references, then Raleigh’s Special Products Division takes lack of information to a completely different level, it seems to be cloaked in mystery!

The only source of information I’ve seen on this new numbering system was posted as a comment on an online forum. There is nothing cited as the source for this information. The proof for this numbering system has been entirely generated by owners confirming, from memory, the date or purchase and associating that date to this system. The few numbers I have seen and the accounts I have read do seem to tally and correctly confirm a bike model to the year manufactured.

I really don’t like assuming facts, those two words don’t sit well together, you can’t assume a fact, a fact has to be correct and proved, not assumed. But when there is no other information you have to use what you have. So using what we have, this is the format…

Special Products Number Format:

According to online chat, this numbering format started in 1990 and appears to have ended at 1999/2000. It uses a single letter prefix followed by 5 numbers. As an example you could have F12345

• A = 1990
• B = 1991
• C = 1992
• D = 1993
• E = 1994
• F = 1995
• G = 1996
• H = 1997

Unlike Worksop that dropped certain letters such as ‘C’ and ‘F’, this later format retains them. However, there is some doubt if the letter ‘I’ was used (this isn’t confirmed, it is just assumed that the ‘I’ would look too much like the number ‘1’). Therefore, if ‘I’ was omitted, the remaining sequence after 1997 would be…

• J = 1998
• K = 1999
• L = 2000

If ‘I’ was used then the remaining sequence after 1997 would be…

• I = 1998
• J = 1999
• K = 2000

I’ve seen bikes using most if not all of these letters up to and including ‘K’ and have not yet seen an ‘I’ used in this numbering system, so maybe the assumption about the missing letter is correct.

There isn’t really much more known at the moment but if anyone has any concrete proven information then please let me know, I’d really like to hear. I always keep an eye on this system and also receive regular emails about it so I’m sure my data will grow soon and I’ll be able to add more concrete detail to this.

Raleigh Special Products SB & SBW Frame Numbers

At the beginning of the post I mentioned that some aspects of this would be my thoughts, me just thinking out loud while still trying to formulate and prove things in my head. This is now that part of the blog. Caveat; there is no confirmed evidence for the next couple of sections, it is all based on trends I’ve seen in the SB numbering system and actual bikes and frame numbers that I have viewed. I don’t normally write about things I can’t prove as fact but I’m doing this in a hope to gather more information. Because these are just my thoughts, I might ramble on a lot so please forgive me if this makes little or no sense, as I said, it really is just a basic layout of my thoughts at the moment.

The lack of information really makes the late 1980s/early 1990s period difficult to understand in terms of top end Raleigh frame production. So I have to look at data and physical evidence to see if I can spot how and when things changed and progressed. I would really like to see my thoughts proved at some point in the future, it just takes time and a lot of patience to wait for the right bikes to appear and fill those knowledge gaps.

The 1989/1990 period seems a bit mixed up when you find Raleigh information describing their facilities. The extract below is the earliest I’ve seen Raleigh Special Products Division mentioned. This catalogue is dated January 1989. The snippet also ties in well with 1989 and the relaunch of Reynolds tubes and frame transfers by displaying the new format and simplified Reynolds 653 frame transfer for their Record Ace Moderne.

That text seems very clear and Special Products Division gets a mention a total of four times in just that small snippet. It specifically mentions that “Raleigh lightweight bicycles and framesets are hand built in the Special Products Division“. However, if you look at a later 1990 Lightweight catalogue (below), Raleigh have mentioned their ‘Lightweights Division’ and go on to say the same thing, “Every lightweight racing cycle is hand built by our Lightweight Division craftsmen”.  The ‘Lightweight Division’ is a phrase that Raleigh used in the mid 1980s when referencing the older Lightweight Unit bikes, so seems like an older term.

So is it ‘Special Products Division‘ or ‘Lightweight Division‘, or did Raleigh just like to mix up their own terms just to confuse everyone in this period?

Regardless of the duel terminology, I’m going to go with the January 1989 reference being correct, I can’t see Raleigh using such a specific term as Special Products Division if it didn’t exist.

The keen eyed however will notice that the frame number timeline I gave earlier for Special Products starts with ‘A’ at 1990 and not 1989. This means that the Special Products  timeline seems to tie in with the same period as the launch of the DYNA-TECH range, first seen in the 1990 catalogue; the 1989 catalogue only displays a range of steel framed bikes; the DYNA-TECH technology was being tested by the Raleigh team during the same ’89 year.

So what was happening with frame numbers in 1989 because Raleigh were already using the Special Products Division name but the timeline for Special Products frame numbers didn’t appear to start till 1990. The ‘W’ reference frame number was still being used in 1989, the latest ‘W’ reference frame I have seen to date is a mid year 1989 frame; there may be later frames, I just haven’t seen one yet.

As for the SB reference, the latest original paint SB numbered frame I have seen with an original SBDU oval transfer is my own SB9000. Based on other frames from around the same period, I’m placing SB9000 towards the mid to later part of 1988. The SBDU oval is significant as it is a direct reference and indicator that the SBDU was still an entity of some kind with Raleigh towards the end of 1988. The style of Reynolds 753 frame transfer is also appropriate for 1988 before the simpler transfer re-design in 1989.

And this is where the ‘SBW‘ reference makes an appearance. The SBW reference also marks a small change in the size of font size used for the frame number stamps.

SBDU Ilkeston and Nottingham larger stamp size… approx 5mm digit height.

SBW Numbers and Raleigh Special Products SB smaller stamp size… approx 3mm digit height.

More on that font size in my future frame number format post.

SB numbers were sequential and at some point around SB9100 I’ve recorded a handful of ‘SBW’ numbers. These SBW frames continue in the same number sequence as SB frames, and judging by their frame design, they are the same date period, the difference is that they have an added ‘W’ on the ‘SB’ prefix.

So far, I have few SBW numbered frames recorded between (approx) SB9100 and SB9300. Some of these are reportedly Raleigh team frames and they have both an SBW number and rider initials/date, while others are standard looking Reynolds 753 lugged frames with just the SBW number.  Two of the reported team frames are stamped with ’89’ and ’90’ respectively. These year numbers are meant to denote the racing season the bike was built for, so again, these dates tie in with the period I’m writing about.

There is a common myth that all team bikes are built at the end of the year in readiness for the upcoming season; this means that a bike stamped ’89’ was actually built in 1988, and a bike stamped ’90’ would have been built at the end of 1989. The myth all stems from the confirmed stories of team mechanic, Jan le Grand, arriving at the SBDU in Ilkeston late in the year with the sizes and details of the riders and TI-Raleigh bikes for the following year… but that was late 70s and early 1980s, and with later Raleigh team bikes, we really have no idea or confirmed stories of when a team bike was built.

With the TI-Raleigh team, which often totalled around 18 riders, and with some of these riders having 4 or more bikes, it amounts to a lot of bikes and a lot of work to prep and build them, so starting well in advance makes sense. But with later teams, it is impossible to know when they were built, some bikes could well have been built early in the season. An example of a later 1980s team frame is the late David Rayner’s Raleigh Banana team bike. This bike is duel stamped with SB9057 and DR.60 1 89 (Initials, size, bike number, year). Because the SB number is very close to my own SB9000, I would place this frame at late 1988 built for the 1989 season.

This is how some of the SBW numbers fit into a small selection of SB numbers in the 1988 to 1996 period. Note that the SBW frames from 1989/1990 have a mix of the two different styles of number stamp format.

Whatever was happening with the names of Raleigh’s production units, and regardless of when some of these bikes may have been built, the evidence is that 1989 seemed to be a transitional year, things were changing…

Following this small diversion of SBW numbers, the sequence reverts back to just using the ‘SB’ reference. My own SB9529 which is a DYNA-TECH lo-pro frame, is an example of the sequence returning back to the standard ‘SB’ format (with the smaller Special Products stamp style).

SC Frame Numbers

What on earth is an SC number? The simple answer is that I’m still thinking about it. But before I get to the SC numbers, it’s worthwhile looking at the probable end of the original SB reference.

It’s very clear that SB numbers continued past the disappearance of the SBDU. I don’t think there is a known official reason for this continuation, and there are a few that think the SB numbering should have ceased with the end of Ilkeston, not me though. There is a precedent here and maybe it is a similar story to the ‘W’ reference which was continued past the closure of Worksop. Maybe the SB was continued to differentiate ‘specials’ against the standard Special Products models in the same way that the ‘W’ differentiated between Lightweight Unit and Nottingham’s standard bikes.

The stories I hear are that SB numbers in the post SBDU era were reserved for team rider bikes, special builds and prototypes – these stories do seem to fit as there are indeed frames with SB numbers in the Special Products era that have either rider initials, rider names and/or the word ‘PROTO’.

I’ve mentioned a few times about how difficult it is to fit SB frame numbers into a timeline following the relocation to Nottingham as there just aren’t enough bikes. But some of the bikes that do exist have clues in either the stamping style, tubing type or their stories, which makes it possible to put together a ‘skeleton’ of a timeline. A brief example of those numbers are listed in the table above. The numbers I’ve listed take the SB numbering system from 1988 throug to approx 1995/1996 where they reached just below 10,000… SB9956 is the latest I have on record.

I have nothing recorded again until approx 1997 when a cluster of Raleigh frames with an SC number appeared. These ‘SC’ referenced frames are all in the SC1000 – SC1200 range. The size and style of the SC stamp is exactly the same as the size of the smaller font ‘SB’ stamp used by Raleigh Special Products Division from 1990 onward. It is also stamped in the same location along the edge of the BB shell. Most of these SC frames are Tig Welded Reynolds 853 frames with a straight blade fork. Others are Titanium frames. The 853 frames are similar in design to the type of frame seen in Raleigh’s Special Products catalogue dated February 1997.

SC1048 is also stamped with a rider’s name from the 1996/97 Foreldorado – Golff cycling team. The Dura-Ace 7700 components used on these bikes also date to 1996/97.

There is no real conclusive evidence of what the SC number system was or even when it was started. Did the SB number system reach SB9999 and Raleigh simply changed the prefix to SC to start the sequential numbering again? Was it a system that Raleigh used alongside the SB system to denote a different type of production or even a different production facility? Do SB numbers run higher than SB9999? Was the SBW reference something that was used during an SBDU/Lightweight Unit transition into Special Products Division?

Hopefully, if more frames are seen, it will allow me to confirm and update parts of this post with more accurate information.

To conclude

• The ‘W’ reference is well known and accepted, frames are easily identifiable and frame dating is straightforward
• The SBDU Ilkeston era is less well known or accepted but the timeline I have put together is holding up well
• The SBDU era at Nottingham seemed to last from 1987 to the end of 1988. It is proving more difficult to put a timeline together due to the lack of available frames
• The period of 1989 to 1990 and the start of Raleigh Special Products Division together with how the numbering system worked is a little confusing but getting clearer
• The anomalies of small clusters of SBW and SC numbers will hopefully become clearer as more frames surface

All the information in this blog post is based on actual viewed frames and viewed and verified frame numbers. Information is up to date as of August 29 2018.