retrobloke":25fmt26t said:
Thank you all for replies.
Anthony yup thats the one identical tubing even finish and forks look the same the only difference is it's the down tube not top tube, thanks again for reply. What make is the one in the photo, and which frame material.
The bike in the photo is a Merlin that is currently for sale on eBay. For a long time, Merlin Cycles used to offer a steel frame that they called a TDB (for Tange Doubled-butted) and their blurb said it was made with 'the latest Tange Spiral-butted tubeset', so although I've never seen one I presume the bike in the photo is one of those TDBs. It has a spiral-butted seat tube as well. It looks as though the spiral is an externally-applied butting, which must strengthen the tube, perhaps sufficiently to enable a thinner-gauge tube to be used.
The TDB used to sell for £135, whereas the Merlin WCS, which was made out of the highest grade of Tange/Ritchey tubing, was £199. As ever, these were very good value frames, always highly-praised. I imagine that the TDB wasn't heat-treated, but would have been at a level just below Prestige. i.e., at or slightly above the quality level of a generic 4130 db frame like a Cinder Cone or an Eldridge Grade.
I don't know of any other manufacturers that used the spiral-butted tubeset, but Tange dominated the market in those days, so if they were making it it must have been fairly widely used, I should imagine.