531 forks - advice please

a chap here at work commutes to work by bike every day, rain or shine. He recently told me his frame snapped for no reason and that he needed to buy a new frame. I asked about the forks. "They're ok " says he "but seeing the frame suddenly snapped, I guess those will be unsafe too". So he gave me the forks. The frame/fork is 531, early 80's, was always kept nice with no rust, but had had a number of resprays in its time.

Question is, those forks are now ideal for me to use on another project. But i wondered how safe they are. How long might we expect steel forks to last? If I shouldn't be risking it, then what about all those L'eroica beauties that predate this and thunder down unpaved Tuscan descents. Surely these guys are taking big risks. I am all for recycling, and can live with a chainstay snapping, but forks are another matter.

What do others think?

It seems a bit odd for a steel frame to just snap, did it snap at a lug or along one of the tubes? I guess if it had been resprayed a few times there's no knowing its original condition. A nice paint job could be hiding rust inside the frame. I'd strip the forks back to bare metal and assess their condition,. Also you can tap them and see if they give a clear ring, if its a dull sound there's something wrong.

not sure where the on the frame it snapped, but it was origianlly a custom build he'd had from new. Certainly no painted- up rust bucket from the outside, but who knows what happens within, after all he rode it all weathers

I can't see how it could just snap even if it was badly corroded on the inside. Steel just doesn't do that because it doesn't fatigue over time the same way that aluminium does. I guess if it was fillet-brazed and lugless then one of the brazes might have let go, but I'm sure you'd have seen it coming a mile off.

Give them a good inspection to be on the safe side, but I'm 99% certain they'll be ok. I'd be more worried about them still being straight if they've been in a crash.

"snapped" may have been a bad word on my part. but "broke" is certain and I'm not sure where or how it occurred. It was 531 lugged.
Anyway, i'm feeling a bit more reassured now. To be honest any fork I put on that bike of mine (its a winter trainer) is not going to be new. it just wouldn't make economic sense.

one man's misfortune is another's gain eh As above, if the forks haven't been stressed beyond their elastic limit they should go on for ever - or at least, the line graph of fatigue will be an extremely slowly drooping one! I bet there's still a few aircraft and motorbikes built in the 1930's out of 531 that are still on the go. Maybe the chap could give you the rest of the frame? If you saw the downtube off you'll have a very convenient tool for bashing the bottom headset race on!

My local bike shop mechanic would often shudder when he saw the 531 forks on my 1980s Dawes Ranger in the late 90s. He really didn't rate 531 as a fork material due to a bad experience of one of the legs simply collapsing. I carried on riding it though - used to rather like the fork flexing on downhills (even road downhills). Eventually it was the bottom bracket which failed.

Whilst you can never guarantee anything when I first started mountain biking I had a British eagle with a road type 531 fork. That bike had a heck of a lot of pounding to a point that really was not good for the rider but nothing broke. Cant say I have ever had problems with any of my bike forks and I have had a few 531 forks over time. By and large bomb proof.I would add to that that I have never bought a new bike in my life so they probably had a lot of grief even before I got my hands on them
Regards
Peter

Bad brazing apart, I always considered 531 forks to be bomb-proof. Have you seen a front-ended 531db frame? Usually the top and down-tube crease at the start of the butt, a short distance behind the head lugs, and your erstwhile 73deg. head-tube is now about 80deg. The forks? Oftentimes they look like nothing much happened.

but had had a number of resprays in its time.

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who knows what happens within

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A nice paint job could be hiding rust inside the frame.

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Doesn't have to be 'within'...The elephant in the room being that nobody knows what abrasive stuff might have been used by resprayers to remove the old paint, and/or provide a 'key' for the new paint? Thin walled tubes can get thinner walled by this route, too. Fork blades have enough wall-thickness to be (relatively) unaffected.

531 forks were often regarded as rather OTT in that they tended to be stronger than the frame and a head on crunch resulted in an expensive bent frame not a cheaper bent pair of forks. I have a Roger trike that proves that perfectly. forks are perfect , frame has top and down tubes bend to splitting point.