strange item at 50's Peugeot bottom head lug

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pwa
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Re: strange item at 50's Peugeot bottom head lug

Postby pwa » 13 Jan 2021, 6:49am

Having a compromised lug, which the one in the OP is, would bother me on a new bike, but if that one dates from the 1950s, surely it would have failed by now if it were going to. Unless the frame has spent most of its like in an attic it has survived the test of time.

Brucey
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Re: strange item at 50's Peugeot bottom head lug

Postby Brucey » 13 Jan 2021, 8:38am

the lug is not the worry; to function correctly the steering lock must engage with the steerer somehow, and my guess is that they may have just made a hole in it, pretty much at the worst position possible.

The Raleigh + Rudge steering lock designs are notable for the reason that they have clearly gone out of their way to avoid weakening any of the steering components. The Peugeot looks very much like they have done it in a way that makes such weakening impossible to avoid.

cheers
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NATURAL ANKLING
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Re: strange item at 50's Peugeot bottom head lug

Postby NATURAL ANKLING » 13 Jan 2021, 10:15am

Hi,
Pretty obvious it's a steering lock of some description.
I don't know but maybe the steerer has been reinforced?
NA Thinks Just End 2 End Return + Bivvy
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.

Jdsk
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Re: strange item at 50's Peugeot bottom head lug

Postby Jdsk » 13 Jan 2021, 10:22am

pwa wrote:Having a compromised lug, which the one in the OP is, would bother me on a new bike, but if that one dates from the 1950s, surely it would have failed by now if it were going to. Unless the frame has spent most of its like in an attic it has survived the test of time.

I suggest reading Feynman on the Challenger disaster;
https://hackaday.com/2017/10/02/books-you-should-read-feynmans-appendix-to-the-challenger-disaster-report/
https://en.wikipedia.org/wiki/What_Do_You_Care_What_Other_People_Think%3F

Jonathan

Brucey
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Re: strange item at 50's Peugeot bottom head lug

Postby Brucey » 13 Jan 2021, 10:30am

NATURAL ANKLING wrote:...I don't know but maybe the steerer has been reinforced?


It might have been, but I certainly wouldn't take it for granted !

The steerer is the one tube on a bike which you really don't want to break; very unforgiving.

It is perhaps instructive that Raleigh made millions of bikes with steering locks and the Peugeot ones are pretty rare by comparison. It might be that they just didn't sell well, but it might also be that their scheme was fundamentally flawed in some way.

cheers
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Bmblbzzz
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Re: strange item at 50's Peugeot bottom head lug

Postby Bmblbzzz » 13 Jan 2021, 12:57pm

Valid point, but not one that IMO should put the OP off buying the bike. The bike's obviously survived 60-plus years. The lock doesn't appear to be in use and in all probability the seller doesn't even have the key (if they did, they'd probably mention it). If it were mine, I'd take the fork out and have a look at the steerer. If it's got a cut out of some sort, then either replace the steerer or keep the bike for very light duties, no hills, no loads; just looking pretty! Or better - but I don't know if possible - get a new steerer tube welded in.

Of course if it's intended to be a day to day bike, that might not be advisable...

pwa
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Re: strange item at 50's Peugeot bottom head lug

Postby pwa » 13 Jan 2021, 3:40pm

Brucey wrote:The lug is not the worry; to function correctly the steering lock must engage with the steerer somehow, and my guess is that they may have just made a hole in it, pretty much at the worst position possible.

The Raleigh + Rudge steering lock designs are notable for the reason that they have clearly gone out of their way to avoid weakening any of the steering components. The Peugeot looks very much like they have done it in a way that makes such weakening impossible to avoid.

cheers

I see. So anyone thinking of building up a frame and forks like that would be wise to at least get the forks out, clean it up, and have a close look at the steerer.

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NATURAL ANKLING
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Re: strange item at 50's Peugeot bottom head lug

Postby NATURAL ANKLING » 13 Jan 2021, 5:33pm

Hi,
Any frame and forks......any forks new or old needs an eye.
No different if you were viewing any critical part used on the road by any vehicle.
Fabricated parts can have flaws even if they are hidden, by joining.
Its probably more difficult to assess machined parts as machining can remove surface strength which maybe was originally designed in for a reason.
Scratch a piece of glass and it can be broken more easily, tho metal suffers more from fatigue.

Its sometimes surprising how strong materials are when you consider what you put them through and how much you rely on them for your safety.
In this internet world today we seem to scrutinise every thing raised which prompts more questions.
NA Thinks Just End 2 End Return + Bivvy
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.

Brucey
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Re: strange item at 50's Peugeot bottom head lug

Postby Brucey » 13 Jan 2021, 7:46pm

pwa wrote:.... So anyone thinking of building up a frame and forks like that would be wise to at least get the forks out, clean it up, and have a close look at the steerer.


definitely. It is not easy to be sure of what life a frameset has had so I would always check anyway. It is also as well to note that in the 1950s not every tubeset had a nice butted steerer; I gather that in some cases boshing in a length of broom handle to reinforce the steerer was pretty much mandatory if you wanted not to become a statistic.

In addition I am always slightly leery of designs that appear to have fallen by the wayside; sometimes this for cost reasons, but it can equally well be that the design was inherently flawed.

cheers
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