This is a little bit of an oddball. It’s not even my size, a touch too small at 54 cm, but it was cheap and I wasn’t going to turn down an SBDU frame at the price I offered.
So what is it?
Well, I wasn’t even sure when I bought it…
I wouldn’t normally advise buying a frame without asking all the normal questions and seeing lots of images, especially the BB and SB frame number. But the features of this frame were enough for me to take a small, but educated risk. I had a hunch that it was a 531 Pro frame with a frame number dating it to early 1985. However, it was being offered at a very cheap price, so I went with my instinct and made an offer less than the asking price – they accepted it, and it arrived today!
Now that I had it, I could figure out what it was. The advert gave no indication of the tubing, so was it 531 or 753? The front triangle appears to have been brush painted and none of the original decals exist, so I don’t even have a Reynolds decal to work from. The advert also didn’t show an image of the underside of the bottom bracket so I was surprised to see a Cinelli BB shell peeking out from the orange paint and cable guide.
The frame has a Cinelli BB, Cinelli SC fork crown, Prugnat 62D head lugs and Oversize seat stay caps with horizontal Campagnolo 1010/B drop outs. Both frame and fork are stamped with the frame number of 7121. The only other stamp on the BB is the size, but the orange paint is so thick, I can only make out the first digit of ‘5’. Measuring the frame shows that it is a 54 (centre of the BB to top of the top tube).
At this point in SBDU production, Cinelli BB shells were listed as being used on either…
- 753 frames
- 753 or 531c Service des Courses frames
From those descriptions, it could be either a 531/753 Services des Courses (SDC) or a 753 road frame. This however, isn’t a SDC frame as the lugs are Prugnat, and a SDC would use Cinelli – that rules out SDC and the chance of it being built from Reynolds 531c. That means that it has to be a 753R road frame. Another way to check tubing is frame weight.
Frame weight isn’t an exact science but it is an indication that can be used in conjunction with the type of frame details I’ve looked at.
The scales have always proved accurate in the past, and these weights indicate 753R, 1693 grams and 617 grams. 531c would have been in the region of 1900-1950 grams approx and 650-700 grams approx. The earlier Metric version of 753 would have been even lighter, but this is a good weight for Imperial 753R.
So I’m happy to say that this is definitely 753R – the frame and lug design, SBDU information, together with approx weights match up.
This frame was advertised as having a French threaded bottom bracket shell – this is unusual but not impossible. The SBDU would have supplied a French thread if that was the requirement. But after checking the threading, on both the BB shell and fork column, they are definitely British threads, and in very good condition. I think the seller may have been mis-lead by the MAVIC BB that came with the frame. But that just adds to the bargain nature of this frame. The frame and fork came packaged with the Mavic 610 BB and a lovely Stronglight headset. The frame has been correctly chamfered for the Mavic lock rings.
What I want to do now is try and find out a little about its past… why it is orange (the same exact orange as my Silca Track Pump), why does it have ‘Wheelcraft’, ‘Mavic’ and ‘Columbus’ decals? I might never know, but it would be interesting…
Plans now are to try and carefully remove the orange paint and get it back to the blue that I can see hiding under the brushed top layer. The Mavic BB may well be the way I go with the build, a full Mavic group set would be nice!