Seat post diameters on Carlton frames.

[SkipdiverJohn]

I want to try to ascertain the provenance of a mystery wrapover stay Carlton frame that doesn't have any decals on it, and is not in it's original paint either. Can I use the seat post diameter as a reliable means of identifying if a Carlton is made from Tru-Wel tubing? If so, what diameter post would I expect to find in such a frame,and do they have a unique diameter or are they the same as anything else?

 

[Cycleops]

Calling @Spokesmann

 

[Spokesmann]

Check for a frame number first. Look on the LHS rear drop out.

 

[SkipdiverJohn]

I've had a better look at it at work this afternoon! I found a Frame number stamped on BB that starts with WH 7000, which appears to indicate 1977 - so Raleigh era. The original paint, under the horrible Dulux refinish it was given, is a green shade that appears to have something mixed with it or under it - a sort of colour effect if you see what I mean.
Looks to be a factory 5-speed with the gear cable guide located over the top of the BB - not under, so a bit old-school looking. Rear spacing is 120 mm and the dropouts are plain, not any fancy forgings. Brakes are Weinmann/Raleigh dual-pivot centre-pulls. I've had a peruse of some catalogues on the VCC site and I think it might be a Circuit, going on the indicated year of the frame number and the fact it was originally green. Nothing fancy then, probably some sort of hi-tensile, but quite nice nonetheless, and for some reason I rather like the distinctive wrapover stays.
I'm considering the feasibility of doing a budget rattle can resto on the frame and building it up with a pair of alloy 700c's, the rear of which has a 3-speed Sturmey AW hub in it. The wheels that came with it are 27" chromed steels that have definitely seen better days! Cosmetically, it currently looks like a "don't bother to steal me" station bike!

 

[raleighnut]

120mm is 5 speed rear spacing.

 

[midlife]

Corsa came in a green colour.... polychromatic aqua green

 

[SkipdiverJohn]

Corsa came in a green colour.... polychromatic aqua green

Would the stated WH7000 series frame number tally with the build era of the Corsa though?
I really must try to get more of the paint off non-destructively to see if there are any surviving decals. The chainstays are fairly long, approx. 18" if that helps identification.

 

[midlife]

Would the stated WH7000 series frame number tally with the build era of the Corsa though?
I really must try to get more of the paint off non-destructively to see if there are any surviving decals. The chainstays are fairly long, approx. 18" if that helps identification.

Good thinking, by then it was the Giro, Circuit, Grand Prix and some more that have gone out of my head but not the Corsa. I was just thinking green lol

 

[SkipdiverJohn]

Would I be right in assuming the frame is Tru-wel? A seatpost from a 531 frame is too large. Internal diameter is roughly 26mm with the seat clamp bolt fully slack. My Vernier calipers have currently gone AWOL, otherwise I would get an accurate measurement.
Was Tru-wel any better than the type of gas pipe tubing normally found on cheap frames? It's easy to categorise frame tubing into Reynolds, Columbus - and everything else as "gas pipe", but in reality there must have been some variations in quality even among the non high end tubesets
I have ridden many miles on Raleigh 18-23 steel (and whatever it was called previously) so I don't have any downer on basic frames, but I am curious nonetheless how different makers graded their tube steels.

 

[midlife]

Tru-Wel actually rode very well and for welded tubing was actually quite light . The other thing was that Carlton gave their frames quite a sporty geometry in comparison to others which flattered the ride.

 

[netman]

Found this (https://forum.cyclinguk.org/viewtopic.php?t=27519) a few weeks ago when looking for info on my Carlton Criterium (was interested as it doesn't have the wrap over seat stays). It has some decent info on Tru-Wel in the thread...