I sure see a lot of bicycle frames and front ends cut extended and welded. Do you mean heat treated to make the tubing harder? Seems to cut like mild tubing to me.
Blockquote
While it may cut like mild steel it isnât mild steel, itâs a manganese-molybedenum material that reacts poorly to the heat of welding. In the E-Types it was brazed, bicycles were usually silver soldered. It wonât fail immediately, but it will fail if welded. Or so Iâve heard.
Iâve read the critical temperature for the material is around 1,750F. Heat the material beyond that and youâve weakened the metal. Welding, of course, involves localized temperatures much higher than that. Further I was told the brazing they used was accomplished somewhere around the 1,300F.
AFAIR, all that is correct. Reynolds 531 CANNOT be welded, by any conventional method.
1 Like
If I learned one thing in life many have an opinion based on hearsay. But no experience. ie. you mention heat treating after low temperature brazing??? Wouldnât all the brackets fall off into the furnace?
We taklinâ bikes, or Jags?
Within that link, this bit caught my nerdist eye!!
1 Like
IMHO, as often as this topic gets beaten around, there must be some credibility as to the nature of the alloy that was used in the front framework. Having just taken mine down to bare metal, at least with my Series 3, I can affirm that it appears to have been brazed with bronze or similar rather than traditional welds.
My take is that I donât want to risk any chances weakening the front structure from the picture frame backwards. Now forward of the picture frame, I donât think that there would be much of an issue modifying the bonnet hinge framework as it doesnât participate in controlling the torque from the engine or suspension forces.
Just my take as a non expert.
You are correct, and, done properly, mods and repairs can be performed on the picture frame, too.
The side frames were oven-brazed, and CANNOT be joined or repaired otherwise.
I had saved some old frames, and I was able to make a decent join, using eutectic bronze flux rod: that said, I would never put it to the test.
Whats the difference?
BetweenâŚwhich? Im gettinâ lost!!
Yours is probably the most honest answer so far. To many experts. But many are extremely intelligent. The structure Jag designed from the cowl forward is extremely high tech and designed for extreme racing under all conditions. Very simple, but still overbuiltâŚStudy the design.
They also made it foolproof for the worst scenario unexperienced bodymen and hacks worldwide that have a torch in theyâre hand. I have never read any horror storyâs of bad welding, modifications to the structure or crash and burn from those who used the WRONG welding techniques of those who put an engine in one of these cars that wasnât designed forâŚChevyâs and Fords along with the transmissions.
In other words. Jaguar took into consideration all factors and was very successful making them idiot proof. Worst case scenario of my modifications on the front bonnet mount may let it fail and scrape on the ground.
Between a Jag and a bicycle?
Big difference: differing structures, radically different stresses.
Bottom line, both Jag and the bike frame makers know precisely how to successfully join 531 tubing to itself, or to frame lugs.
Yeah, maybe your right. Bicycles see extremely higher stresses then the the
Jag ever will (spindly frames jumping curbs with no suspension whatsoever).
plus where did I mention joining any 531 on my car anyway? I believe I
brought up an alignment issue before my welding experience came under
attack.
Like I said earlier, I see kids welding bicycle front ends to extend them
and they hold up better then welding something unforgiving like bedframe.
Hi,
Chinese cheapo bikes would hardly use Reynolds tubing.
Over here too custom bikes are a big trend, but they donât start with a Raleigh Competition Reynolds, Raleigh Tour De France or Colnago Master really.
https://www.steel-vintage.com/raleigh-competition-reynolds-531-detail
Although I think that the later uses âGilcoâ instead of âReynoldsâ tubing but the same issues.
Cheers,
Pekka T.
Fin.
Funny how we continually go around in circles in J-L. This discussion on Reynolds 531 subframe tubing is well ploughed ground. I distinctly remember in-depth conversations in the old J-L list back almost 20 years ago but this is the earliest one that pops up in an archive search:
1 Like
Different but related to this, Iâd love to see some kind of essay on the design and fabrication of the original frames. I donât even know who made them; Abbey Panels, Jaguar, someone else? I think Porter is the most comprehensive work on the design and fabrication of the cars, but IIRC he has nothing on the frames other than Jaguar stuck them on the front of the tub.
Hi,
All credit to him and his huge work, but I have never felt that Porter much cared about this kind of nit-picking. And this is coming from a BIGTIME nit-picker. 
I know some folks who (incl our Neville BTW) have gone through big effort to find out, which foundry did what at which time etc.
There was a HUGE network of subcontractors in the Black Country in those days, and of course after the 1970âs most of them got merged or just died. When the mergers started to happen, it was Sir William himself, who was afraid that Jaguar simply would be uncompetitive or unable to operate if they were left outside the large businesses. He was very much involved in the British Motor Holdings (BMH) merger and was the chairman of the board, but he then retired when the whole British Leyland giant was formed. And I believe also Lofty England who was the CEO or managing director at Jaguar in the early 1970âs also left the company as he felt there was little that he could do anymore.
Back on topic, I would be pretty sure that the frames of the first 20 cars built by Jaguarâs experimental department were definitely made in house, by the experimental department.
Maybe a good idea to check the detailed restoration reports on cars like 885005, 885004 and 850003.
Then for production cars itâs hard to say, if itâs undocumented. If it was outsourced then there should be orders, receipts and invoices in the factory archives if somebody can go and dig them up.
I doubt that Abbey Panels would have done them, they made all the body panels for sure, but the bodies were built on Browns Lane in the body shop.
Cheers,
Pekka T.
Fin.
1 Like