Crappy featherbed frames......

Given that he OWNS one of the frames being discussed, you would expect at least a semi-competent level of knowledge on the subject. !!?

I know that my lugged Norton frames were pinned and furnace-brazed, and featherbeds were oxy welded.
A HUGE leap forward in technique.

Reynolds etc have been making aircraft tubular frames with this technology since preWW2.
Seen a few airframes in hangers being rebuilt, someone must still be current on it.
And mention of SiFbronze welding of 531 tubing is all over the net, if you spend even 2 seconds googling it...

And you being proprietor of Wolff Welding should be quite familar with the differences too ??

Just seeing fillet welds in bronze should tell you it wasn't brazed - brass flows into spaces, not builds into fillets....

bwolfie said:

Those technologies haven't been used in mass production for decades.
I hardly expect a modern inspector to stay current on a non used practice.

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I don't know about 'mass production', but most of the replica manx etc frames being made these days would be similarly welded.
Unity Equipe in the UK and Ken McIntosh in NZ still use the same techniques ?, and they would account for a fair % of replica featherbed frames ??
If its in 531, any other technique is going to be risky ??

Ken Mcintosh sent me some photos of a lovely Egli Vincent he built some years back, I have the photos somewhere. It was TIG welded, nice job too.
But Rohan is correct, there are a number of custom motorcycle frame builders using SIF bronze. Some custom bicycle builders use this method as well.


Glen

Pretty much every recent Seeley replica I have seen out of the UK is SiFBronze weld (not brazed). Really beautiful looking stuff.

What I have been told (anecdotal) is that Reynolds 531 tubing was not amenable to stick or tig welding so bronze welding with the lower more regional heat and gusseting of joints through build up of the SifBronze bead is where they got their strength (and durability). The chromoly structural tubing used extensively in the States can tolerate the higher local heat of tig or stick welding.

So for a bit of trivia, the Sif in SifBronze stands for Suffolk Iron Foundry

I am glad I have a orginal 57 Wideline Featherbed frame and a orginal 60 Slimline Featherbed frame, my 850 has been in the Wideline frame for over 32 years now, is ridden very hard and has not showed any sign of failing, I don't know about these replic frames as there are still orginal Featherbed frames to be had and usualy cheaper than the replic frames.

Ashley

" Weldability Sif have a heritage dating back to 1925 and the origins of the bronze brazing process. "
http://source.theengineer.co.uk/weldabi ... 1.supplier

Bronze Welding is often refered to as BRAZING . as its NOT Fusion Welding .

http://www.weldability-sif.com/pages/home.asp

Dkt26 said:

acotrel said:

There is one guy here in Australia who makes a decent copy of a manx frame, his price is $2500. you can usually tell a replica by the top bend above the oil tank. On the genuine item the radius changes. Even so, for $900, it might be worth reworking the frame on the photo, however I would never use a slimline frame anyway. It is like fitting a bathtub rear guard of a 1957 Triumph to a good bike.

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What's wrong with the slimline frames? Are the widelines better? I prefer the look of the slimline particularly the curved rear frame/shock structure as opposed to the straight tube on the widelines.
Also, I might be a bit ill in the head but I also love those bathtub triumphs.

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I agree. Slimline frames work just fine. Take a look at this clip from 2010. #500 has an old slimline frame (with many repaired cracks, 500 Dominator engine) . #212 has a McIntosh replica Manx frame (Venom engine) . #500 is in a lower state of tune with 4 speed box and Norton 2LS brake. #252 a six speed and 4 LS Italian brake. Both bikes on methanol. #212 drafts passes the other bike on the main straight so power is similar or better. But #500 with it's "substandard" slimline frame does just fine.

http://www.youtube.com/watch?v=TyekqMox4tw

PS the rider of #212 had 2 second places at the 2012 Manx GP including lapping a 500 Manx at over 100 mph.

I am sure that theoretically one of the featherbed frames might have an advantage over the other, Manx, wideline and slimline roadster and lowboy. But there are so many other variables each bike/rider combination has that in the end it surely does not make any difference unless your frame breaks in use for some reason.

Probably every type of featherbed frame has cracked apart in use, all the originals and all the replicas, especially with more modern tires, riding styles and brakes stressing them.

Heinz Kegler's Daytona 88 wth it's slimline frame often came in ahead of Manx Nortons and other exotic racing bikes throughout the 1960s, but that was surely because of it's preparation and rider and not it's particular frame design. It even scored a World Championship point in 1967, maybe the only slimline frame with that honor?

If any replica slimline frames being made in the USA have a proven record of use or craftsmanship backing them up then I will too.

I would be scared to death to make a complete frame set or other critical motorcycle chassis part and sell it to anyone because if it broke in use I would be liable in a court of law. Now if I sold my shit to someone in another country then they might not be able to come after me legally, but they could come after my reputation.

If I spent very little time and skill bending up a pile of tubing and superficially tack-welding it together and sold it as an unfinished "kit", then when it fell apart in use I could say that it was the workmanship of the buyer that caused it to break. THAT is the sort of thing that the Ebay frame on auction made me think of.

YES, the USA is a free country(allegedly) and anyone can choose to buy or not buy whatever they want, but that also means that anyone can offer up any information or opinion they want, especially since FOX news won a legal case in the supreme court of Florida saying that it is legal for them to lie and distort facts even on network television......

What you are talking about is semantics. Common usage of the term brazing in Australia involves the use of oxyacetylene torch and copper or silver based filler metal. Rod Tingate worked for Colin Seeley in the 70s, told me that all the original Seeley frames were brazed (bronze welded , if you prefer) using tobin bronze, and his own frames are made using the same process with coated rods. The 'welds' on my Seeley frame are bronze, not steel. I've rarely heard a brazed joint being described as 'welded'. Our usage of the term 'fillet weld' usually applies to steel and aluminium welding where the weld metal is substantially the same as the construction materials. A lot of brazed joints don't look like fillet welds, however I suppose they all are in the strictest sense . Do you also call silver soldering or tin-lead soldering 'welding' ?
Does using TIG or MIG welding for frames include an obligation to stress relieve the frame in the jig?
There has been a slow discussion about frame building going on around here for some time, the best joints seem to be made using bronze. Some of us have TIG available, but the material requirements and the temperatures involved give a few worries about cracking. The last frame we made was chrome moly for a 750 SFC Laverda, my own Egli copy of a TZ750 two stroke frame was made using mild steel tube, a few steel welded joints and much brazing.

The only Norton frames I am aware of that used brass (tobin bronze) were the old lugged versions - they pinned them up and heated em up to red heat in a furnace, and the brass powder flowed into all the lug/tubing joints.

Reyolds Tubing were always very careful to call their 531 tubing 'bronze welded', if you look around.

Soldering brazing fusion welding has been around since preRoman times.
No doubt the discussion will continue for more years to come...