Sometimes my frames come to me without any signs of originality meaning that I can’t accurately identify them. There is seldom a known history to accompany a 2nd hand frame. SB7121 was a classic example of this. I bought it on a whim, based on a basic description which indicated that it was probably a Reynolds 753 frame. The frame number dated it to 1985 and it had a hand painted finish with ‘Wheel Craft’ frame transfers, but underneath the paint, it was 100% an SBDU. I wrote an initial blog post on the frame but always wanted to come back and dig deeper and take a proper look into what it was.