steve Posted January 26, 2014 Report Share Posted January 26, 2014 I'm in the process of rebuild the engine on my 250 Armstrong so I have the rolling chassis sat empty and want to take the opportunity to move the footpegs a little. The frame was advertised as being Reynolds 531 and I always thought you could only braze 531. However it doesn't look like any of the frame is brazed by Armstrong. Does anyone know if all the frame is 531? In particular what material is the flat steel plates the footpeg brackets are mounted? I will also think about altering the steering head angle at a later date so any info / advice re welding or brazing in that are will be welcomed, thanks. Quote Link to comment Share on other sites More sharing options...
woody Posted January 26, 2014 Report Share Posted January 26, 2014 I wonder sometimes, if frames advertised as being 531 may only have had a small section of 531 in them... maybe the part where the sticker was... Can't advise you on the type of metal but if it's any help, I mig welded my Armstrong frame when repositioning the footrests with no problems at all. On the modified Armstrong on the other thread, all the frame alterations were tig welded. As an aside, my mate who is a coded welder, reckons that all this stuff about you can only braze this or tig that is not always correct. He seems to be able to tig just about anything. He's done frames that are supposedly 531. 1 Quote Link to comment Share on other sites More sharing options...
suzuki250 Posted January 26, 2014 Report Share Posted January 26, 2014 (edited) You shouldn’t have any problem mig welding 531, I would use a wire like E70S6 it will pretty much weld any steel. (E70S6 quite expensive about £40 for a small roll) But you shouldn’t have to much problem with standard wire Edited January 26, 2014 by suzuki250 Quote Link to comment Share on other sites More sharing options...
bashplate Posted January 27, 2014 Report Share Posted January 27, 2014 might be worth trying chrome moly rods with the tig ....or if in doubt stainless tig rods stick to anything. 1 Quote Link to comment Share on other sites More sharing options...
steve Posted January 28, 2014 Author Report Share Posted January 28, 2014 Thanks for the advice on welding, I will use my mig to do the foot peg brackets and then give the frame a quick lick of paint to tidy up, when I've ridden it a bit I'll give some serious thought to any other changes I might make but will need to enlist help from somebody skilled in tig or even brazing. Like Woody says I wonder how much of the frame is 531? I'm sure the flat plates won't be and I doubt the square sections are either, Wonder if there's anybody still around who used to make the frames, I presume they were made in house in Bolton. Quote Link to comment Share on other sites More sharing options...
mattylad Posted January 30, 2014 Report Share Posted January 30, 2014 Fantastic book on the CCM/ Armstrong history Rolling Thunder: Ccm Motorcycles: the Odyssey Author Henshaw Quote Link to comment Share on other sites More sharing options...
firedfromthecircus Posted January 30, 2014 Report Share Posted January 30, 2014 The problem with 531 is that it was not designed to take the heat of welding when it was developed (1930's I think). You can weld it, but the heat affected zone will be weaker than the metal was designed to be. That means that failure around the weld is a real possibility. I would have thought that only the tube sections would be 531, but I don't know for sure. I think it's unlikely that Reynolds would have used 531 alloy to make plates and square section for such a relatively small project. Even so, if you want to modify the frame, there's not much wrong with brazing IMHO! Quote Link to comment Share on other sites More sharing options...
suzuki250 Posted January 30, 2014 Report Share Posted January 30, 2014 (edited) 531 is just a brand name, Its just a moly-chrome medium carbon steel so I would guess if its arc welded they would use a similar material for the flat and box section If you use a High tensile mig wire there should be no problems, as long as you don't chill the welds in a draft Or you could anneal the frame like Norton did with the works Manx’s Edited January 30, 2014 by suzuki250 Quote Link to comment Share on other sites More sharing options...
shakennstirred Posted May 15, 2016 Report Share Posted May 15, 2016 The Beamish Suzuki 531 frames are bronze welded so the Armstrong maybe the same Quote Link to comment Share on other sites More sharing options...
seth29 Posted July 31, 2016 Report Share Posted July 31, 2016 Hi all We this is a subject close to my passion. There is lots of speculation about the frames on Armstrongs. I have spoken to some of the people that worked @Armstrong in the 1980 and some are still making frames for other people, but none can tell me if it was top quality steel or just cold drawn steel.??? I have mig welded lots of them with no problem. As regards to moving the foot pegs. Don't I have a bike with foot pegs moved back 50mm Amd the bike is front end light, and won't turn in correct, the standard set up on the bikes is bang on. Don't change... As for the fork angle. It's a big job to Chang as you will have to extend the length of the top tube to get good clearance from the exhaust front pipe. Just take the fork springs out and turn the steering and you will see what I mean it gust misses the front pipe in standard setting. I have a standard 250 Armstrong and it rides bang on... Spend you're money on some good suspension that's the key. Look at some of the trick Fantics and they run standard geometry. Seth... 3 Quote Link to comment Share on other sites More sharing options...
still trying Posted August 9, 2016 Report Share Posted August 9, 2016 Hi, before you change your steering head angle check out "Trials Australia" website, go into twinshock & classic trials, scroll down to "Steer clear". It's all about steering geometry and the various things that affect it. As for welding molly steel, Brazing, gas welding, TIG, & MIG are all fine. Its the cooling that is critical. Slow is good. If the metal is less than 3mm thick then it doesn't need to be stress relieved. (Very important fact for the guys making roll cages in race cars). There is a lot of discussion in "weld or Braze" in classic trials on this site. Hope this helps Quote Link to comment Share on other sites More sharing options...
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