Blog Featured Posts Road SB9 SBDU Ilkeston TI-Raleigh

SBDU SB9 – Sharing Frame Numbers Across the Pond

SBDU SB9 has certainly sparked interest in the Raleigh community since it returned to the UK. And it is set to create more. If SB9 is now settled back in the UK, how can it also still be in the US!

The SBDU were not perfect. Especially when it comes to stamping frames. I have a classic example with a frame stamped as SB4522, but which is actually SB5422. Then there is also SBSB2692 – note the double SB stamp. I also have SH377T which has the wrong size stamp on the bottom bracket. If I have this many in a small collection of SB frames, how many might exist in the entire Ilkeston production? Several hundred?

A Brief Explanation

Confused Emails

Way back in January 2019, I received an email from a guy in the US who said that he owned SB9. The email was actually about the subject of early Imperial 753 tubing – just my kind of topic!

Anyway, in my reply I made reference to SB9 and how I had used the images of SB9 in my SBDU research. He replied saying that I must be mistaken. He had owned the bike for 20 years and had kept it almost ‘hidden’, to use his words.

The SB9 I referred to in my reply had been published on the old Yahoo site. So I checked the current email address against the one logged against the Yahoo photo album, and it didn’t match. I often have incorrect SB numbers quoted. As confused as I was, that is where I left it.

I Published My SB9 New Arrival Post

Less than 48 hours after I published my New Arrival post, I received another email… with the intriguing title… “Two SB-9s??”

Hi Neil,

I just saw on your site that you just obtained SB 9.  So it looks like there are two SB 9’s?
The one you just added has the serial number parallel to the bb spindle axis.  Mine has the serial number in different orientation with the SB on top, and the nine below.

One thought – is number 6 accounted for?  Perhaps they flipped the number die when stamping?  Or did they just loose track?  Kinda strange.  Any idea of there are other “duplicates” out there?  That could change the total counts.

Keep up the great work!

Yep, this was from the same guy who emailed me back in January 2019. I emailed back and of course asked for images!

The ‘Other’ SB9

Frame Number

And there it was, an authentic looking SB frame number stamp. The only difference to mine was the position of the ‘9’ relative to the ‘SB’.



Another original example. Very clean with a Campagnolo Super Record and displaying features I would expect from a very early frame such as the use of the ‘no border’ TEAM graphic on the top tube and the small circular bottle bosses with no step at the base. These features changed by SB15 (the next original SB frame).


What Could Have Happened?

Anything related to what could have happened here is only speculation. I try to keep my blog free from speculation but sometimes there is no choice.

There are a couple of possible scenarios.

A Simple Counting Error

If we keep in mind that this was the start of a brand new unit, they would have been busy with a new environment, new frame styles, continued development of Reynolds 753 and of course their work with the TI-Raleigh team. There would have been new processes and methods and maybe someone did just get the numbers wrong? Maybe the first SB9 was built and stamped, but not recorded. Then the next frame came along, the log was checked, SB9 hadn’t been recorded and another SB9 was created.

A Mistake

What if..?

What if one of these frames was meant to be stamped with an ‘8’ but the number ‘9’ stamp was mistakenly selected and used. You cannot then go back and remove the ‘9’ and re stamp it with an ‘8’. You also wouldn’t bin the frame because of the error.

The whereabouts of SB8 is currently unknown. I dislike speculation, but it is a fact… the location of SB8 is unknown.

Which SB9 Came First?

Is it possible to tell?

Although there isn’t much known about the early frames, we are lucky that SB6 and SB7 are known and that their owner is happy to share information, and answer my questions. The owner of the other SB9 is also happy to share information and also has allowed me to share his images.

I also have data on hundreds of other SBDU frames, so I’m able to compare features.

My SB9 has a couple of subtle features that differ from the other SB9. I can use the differences to place these 2 frames in a timeline and therefore confidently say which was built first.

SB Number Format

SBDU frames have a very clear and readable format for frame stamping. This stamp format changed several times. There were at least five different styles of how the SB prefix, frame number and frame size are positioned. And even within some of those, there are slight variations.

First Format

The first format is seen in SB6 and SB7. It is ‘SB’ followed by the number. In the case of SB7, there is a slight slope to the 3 digits. The ‘B’ is slightly lower than the ‘S’ and the ‘7’ is slightly lower than the ‘B’. This format changes with SB10.

Second Format

From SB10, the format changed. The numbers were no longer in line. The number appeared below the ‘SB’. Here is SB14 as an example…

SB14 Showing Second SBDU Frame Number Format
SB14 Showing Second SBDU Frame Number Format

This format continued as far as we know, until SB58 – this frame was the first time the third format has been seen. The third format introduced the frame size for the first time, situated alongside the number.

Comparison of SB9 and SB9

Here are SB9 (UK) and SB9 (US) side by side…


You can see that my frame on the left follows the first format and the other frame follows the second format.

Seat Tube – Seat Pin Slot Reinforcement

This is the second subtle difference between SB9 and SB9. Just like the frame number, there are variations on how the SBDU dealt with the slot at the back of the seat tube. There were at least 4 different variations depending on the type of seat lug in use.

First Seat Tube Slot Treatment

Both SB9s use the same seat lug. However, my SB9 is dealt with in the same way as SB6 and SB7 (confirmed with images). The seat tube is slotted and a large hole is drilled at the base.

Second Seat Tube Slot Treatment

The other SB9 is different, and matches the same method as later frames. Not only is the slot cut and hole drilled, it has a reinforcement washer brazed at the base of the slot. Here is SB14 as an example…

SB14 Showing Second SBDU Seat Tube Slot
SB14 Showing Second SBDU Seat Tube Slot

Comparison of SB9 and SB9

SBDU SB9 UK and US Seat Tube
SBDU SB9 UK and US Seat Tube

My SB9 is on the left and you can see a simple, maybe even crude, slot with a large hole at the base of that slot. SB6 and SB7 are identical to my SB9. The other SB9 on the right has a washer brazed in place over the hole, acting as a reinforcement, similar to SB14.


The SBDU weren’t perfect. They got things wrong. There is history of incorrect frame stamping.

Both SB9s are genuine, both are very early examples from the very start of the Specialist Bicycle Development Unit at Ilkeston.

Did they simply get the record keeping wrong and stamp 2 frames with the same number 9. Is one actually SB8, but stamped as SB9 in error?

I guess there is no actual conclusion, we may never know what happened… until SB8 finally reveals itself!

With regards to which SB9 came first, I do feel, based on the 2 frame features I’ve demonstrated, that my SB9 was built before the second SB9 first.

Thank you to Mark, Mike and Nick for their helpful information and for permission to use their images.

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.