currently the interwebs' best repository of Viscount wisdom is a single thread on the cycle touring club forum, based in the UK.
the thread itself is the longest on the forum and at (currently) 24 pages,
is a bit tricky to sort through.
doing a search for something else I came across this great exchange
on page 9,
fascinating info on the tubing that Aerospace frames were made from,
Thanks for that. I have read this information before and it is all very true.
Phoenix Tube Co. Ltd. made steel tubing mostly for aerospace applications e.g. parts of the struts on Boeing 747s, fuselages on stunt aircraft. Originally it was used by Lambert for their frames. This was for - allegedly - three main reasons:
a) Raleigh would not allow them to use Reynolds as they were really worried about this new 'upstart' Lambert company who were claiming that they would soon be making 50,000 bikes per year.
b) Great price.
So what of this mythical Phoenix tubing? It came in two grades, '101' and '1027'. When Lambert went bust in 1974 (an amazing story in itself by the way...) Viscount was born out of the ashes of this mess. Viscount's 'Aerospace' frames were made to the same specification, in the same factory and on the same jigs as Lambert's lugless frames. The grade of tubing used was also Phoenix '1027'. In other words Viscount frames were basically the same as Lamberts albeit built to more rigorous standards. If it aint broke, etc...
It is only my opinion but, and this is backed up by other frame builders I have spoken to, that the Phoenix tube was amazing! Viscount greatly increased their quality control compared to Lambert and amongst other things, conducted a number of tests on the Phoenix tube.Allegedly, despite being markedly thinner walled, the Phoenix tube in these tests out performed Reynolds 531 double butted (that statement is bound to enrage the purists but there you go!). At the time Viscount backed this claim up with a report - which was available to any one - of the testing carried out by an independent company. I am desperate to see that report by the way so I can add it to my very nerdy Viscount database/records.
The official spec of Phoenix '1027' tubing was as follows:
Cold drawn seamless chrome molybdenum alloy steel
Exceeds the performance required from the following aircraft specification:
American Aircraft Specification MIL-T-6736A
British Aircraft Specification NR 3T50
Minimum physical properties:
Yield stress tons/square inch = 45 tons
Tensile strength tons/square inch = 50 tons
Elongation percentages on 2 inch gauge length = 12.5%
The Viscount Aerospace frames were also subject to a variety of 'to destruction' tests required by American consumer regulations. In addition other unique to Viscount brutal frame/tube tests were also added. One of my favourites was where 12000lbs in weight was hung off one of the frame tubes to measure deflection/lugless joint strength.
I have quite a few Aerospace frames, one of which has done over 60,000 miles. All of them are fine even after 30+ years of (ab?)use. Also, I am, ahem, not the lightest of people either so carrying my carcas is a tough test for any frame! It is very impressive how such thin walled steel can survive such a battering for so long. What is not widely known is that the Aerospace frames were used extensively by the Coventry Olympic Viscount team in the 1970s. The team won many championships on these frames including those in the grueling sport of Cyclocross.
Cyclists can be a surprisingly set in their ways lot when it comes to their bicycles (a bit rich coming from me?). I think this partly explained why their was always a degree of resistance to Phoenix tube. I mean, how could a noticeably thinner tube be so much stronger than Reynolds 531 DB? Still, aside from Viscount, quite a few frame builders used it in the 1970's for their frames. Their is more of it around than you may think! There are also quite a few Lambert frames running around speedway circuits even to this day. Some of the racers are not even aware of this...
It saddens me a bit that the engineers who created Phoenix 1027 and 101 cycle tubing have never got the recognition they deserved.
Hope this is all food for thought!