Sometimes I don’t need to go searching for frames, sometimes frames find me. A few nights ago, a frame popped up on my screen, just a few photographs and a small description. It was a Raleigh Specialist Bicycle Development Unit (SBDU) frame, built in their Nottingham unit. It is a very similar frame to the SB8945 frame that I picked up a few months ago. Sometimes the decision to buy a new frame doesn’t take long to make, and even though I’d just seen a few non-detailed images, I contacted the owner and bought it. It was in my collection a couple of days later.
So what was it that got my interest?
My search for a Banana flavoured SBDU frame has been a long one – they just don’t seem to exist anywhere. I’ve seen so many SBDU frames over the years but I’ve only seen a few examples of this scheme. And this one is in beautiful condition, an excellent example. In fact, some parts of it look like it has just come out of the spray booth.
So what exactly is this frame?
It is a 1988 Services des Courses (SDC) model, built with Reynolds 753R Imperial tubing. The SDC was the top level frame produced by the SBDU and featured Cinelli fittings; this frame has a lovely Cinelli SCA (aero) fork crown and Cinelli ‘Spoiler’ bottom bracket shell.
My other Nottingham 753R SDC frame has Shimano vertical rear ends but this frame has the conventional, but classic horizontal Campagnolo 1010B ends.
The frame number, SB8868, dates this frame to 1988 (it is pure coincidence that the frame number contains ’88’). The SBDU moved from Ilkeston to Nottingham at some point between numbers SB8367 and SB8438, in the early part of 1987. From the frame numbers and dating evidence I’ve seen from this period, it was clear that frame production wasn’t as high as it had been in the late 70s/early 80s, so I’m happy with 1988 as the date.
Later 753R, like this frame, had a slightly different gauge (wall thickness) compared to the earlier Metric gauge 753 produced in the 70s. For that reason, later 753R frames can be a touch heavier. But this frame weighs in at a very good 1756 grams – that is really good for a large frame like this (59.5 cm)
Because it is a large and relatively light frame, it was probably going to be the lighter gauge of 753R. The standard gauge for a single butted 753R seat tube was 0.7/0.5 mm (22/24 SWG) and took a 27.2 mm seat pin. This frame was probably 0.7/0.4 mm (22/26 SWG), requiring a 27.4 mm seat pin.
I have a good 27.2 pin that fits well into a 27.2 frame. I use that pin as a guide with all my frames. This pin slips straight into this seat tube. It actually has a little side way movement. The best way to measure for seat pin size if you don’t have a spare pin is with long spring calipers because you can reach past the seat lug. The seat lug can sometimes become mis-shaped which can give an inaccurate result.
I took this measurement from approx 4″ inside the seat tube where the tube should be round. It comes out at 27.38 – if you factor in a small tolerance in my measuring, you have 27.4 mm.
Now I know exactly what it is, what are my plans..?
Well, this frame has been ‘de-badged’ as a ‘Banana’ – those transfers have been removed, so top of the list of things to do is replace those missing transfers. Next up is the choice of group set… this is a 1988 Banana and in that year, the professional team were riding Shimano Dura-ace 7400 series so after some thought, that is the group I’ll be fitting to this bike. I’m not aiming for 100% period correct, but this series of Dura-ace is the only choice.
Dura-ace 7400 was introduced in 1984 and by 1988, it had moved on with 7401 and 7402 – I’ll hopefully be fitting an 8 speed mixed group of 7400, 7401 & 7402, with down tube levers and single pivot SLR brakes.
This frame has helped me tick off a few more items from my SBDU wanted list. It adds to my little sub collection of Team colour schemes and sits in the collection next to my current TI-Raleigh and Panasonic Raleigh bikes.
