The later frames were built in 531SL so could well be 🤔.
This is Bernard on his way to victory in the 1978 Grand Prix des Nations, definitely a different frame with no brazed on top tube cable guides and more distinctive raised bottle cage bosses.
I love using the Sustrans routes when planning rides as much as possible and can use the routes to link up with the Ridgeway and South Downs Way. They use both on and off road cycle paths and Canal towpaths, the on road sections are very quiet so really safe car free cycling. Normally very well...
Just thought I'd add looking a the first photo that the seat clamp may be over tightened with the 27mm post and should be a 27.2, would need to view it from the rear to confirm. This is a common issue with the threaded seat lug used on the earlier SB and Raleigh/Carlton Professional MkV frames...
It's SB 6144 size 58.5 seat tube c-t , would be under 1700g without the Super Record headset cups, dropout adjusters and seat clamp bolt so very light considering the long Campagnolo dropouts and longer chain stays for extra clearance 👍
More pics please, all I can see is that it's been repainted and the seat tube decal is completely wrong and was never used by Raleigh for the Ti Team livery.
Can't id an SBDU from just a photo of a seat post, would need more photos of the frame details... dropouts, seat stay caps, lugs, bottom bracket, chain stay indents, fork tangs?, paint , decals and bare frame weight 👍
Interesting seat stay arrangement, they appear to be double taper oval but but turned 90⁰ maybe for more comfort or should I say the new buzz word compliance .
Very nice frame so definitely worth restoring. Looks like it was the top of the range offered as a complete bike with Dura-ace or frame only. What does the bare frame weigh, I'm guessing around 1700g 🤔
https://www.retrobike.co.uk/threads/all-things-orbit.221678/page-5
I always give a big thumbs up 👍 to tank drivers who wear a helmet, you wouldn't want them to bang their bonce on that hard interior shell and loose control of the vehicle....Mmmm don't think a plastic helmet from Decathlon is gonna save me 😉
Very nice early ALAN, I have the same frame as yours from the first year of production 1972 which have the longest version of rear dropout. Mine has an English threaded bottom bracket 👍