I'm researching an old Mercian bike that I may buy.
A beautiful machine but it is 20 years old. Nice lugged
steel with 531 tubing. I asked a local mechanic about
the bike and he said that an old bike might not be
"as lively" as he put it. Metal fatigue or something.
The bike looks to be only lightly used. I've never
had the impression that steel would degrade
in quality just by sitting in one place--in terms
of the ride or strength. If ridden hard--for a looong
time maybe--metal fatigue is a real phenomenon but
it sounds like a non-issue for a lightly used old lugged
bike. Thoughts?

With all due respect to those who use that term, it's played-out. The term in itself IS based on a valid concept. Operative word being MIGHT. No a bike can NOT suffer too long a shelf life. A bike that's been riden,I'd say 20,000 miles could show signs of wear, the area of the bottom bracket can get "soft".But I really feel funny saying that,as I said it's so not very likely. A pro can ride tens of thousands of hard miles per year,they use this as a reason to change bikes, the teams can afford this.. If a bike was raced and or crashed,the results of such use and mis-use far surpass a 20,000 mile lifetime. I'm 200 pounds,some bikes flex a little,they have resiliance as well. I don't ride enough to wear 'em -out, did the original owner of yours? Look for rust and a shadowy appearace 'round the bottom bracket,where the crank is, other spots also. The bike looks slightly used ,most bikes are not used enough to compromise the frame integrety. A pro or enthusiast has their reasons ,the bike mechanic has reasons too.

The idea of steel getting "soft and old" is well disputed by Jobst Brandt. He states that steel either has its "springiness" or it does not (ie. breaks). Google him and you will see his credentials. By the way, get the Mercian! If the price is fair and it fits your needs (and it's your size) you will never regret buying it.

A racing bike used for thousands and thousands of miles by a hammering profesional will lose it's liveliness over time. A bike riden, even for many years, by a sports/exersize oriented amateur probably wouldn't suffer much metal fatigue. Assuming a steel bike of course. Aluminum say, has much less metal fatigue resistance, so maybe over time with a heavy strong rider, who knows? Never-the-less, I doubt you'll have any problems. I have a 1974 Austro-Daimler Vent Noir that still feels more or less just as "lively" as when I bought it way back when.
Enjoy it, ride it, love it!

I discussed this once with a buddy of mine who is an aircraft engineer. He said a bicycle frame will have the same stiffness until it fails (cracks, breaks, etc.). I used the analogy of a paper clip, saying, "what about a paper clip, you bend it back and forth, back and forth, you can feel it getting softer, then finally it breaks." He pointed out that you're bending the paper clip over and over, not simply flexing it like a bike frame is subjected to during normal use. Will a bike frame eventually fail given enough use? Yes, but you won't feel it getting "soft" beforehand. If you feel a real difference, look closely, you'll probably find a crack-

Well said. It also sounds like kaiju-velo's mechanic would rather not work on older bikes and is trying to discourage you from buying it. I agree with ploddersluk, buy the bike but be prepared to find a mechanic more willing and/or qualified to work on it if you won't be doing it yourself.

I have a steel bicycle that's over 50 years old and has obviously been much used. If it lost any of it's liveliness, it must have been doing jigs at night after long rides when it was young. It still has a wonderful feel to it.

Maybe not as "lively" as a modern aluminum racing-oriented bike? I wasn't aware that steel bikes were lively to begin with. In any case, the first ride on it will make up your mind more than any advice given.

I concur that a given steel frame should feel pretty much the same through its life, until the tubing, the lugs, or the brazing actually begin to fail. A long-wheelbased, slack-angled older frame, engineered expressly for riding long distances on cobblestone roads in Europe, will always feel softer than a contemporary racing frame, particularly one designed for criterium or time trial use. I am only marginally faster on my 26-year-old Bianchi than on my 48-year-old Capo, and the frame makes a difference only on climbs and sprints. For flat cruising, tire rolling resistance and my own aerodynamics dominate, and it really doesn't matter which frame I am on, other than the fact that the Capo is more comfortable and forgiving on the bumps.

Back in my racing days we just about all replaced our bikes every season. The official line was that the frames had gone soft. I personally never noticed any such thing, but went along because it was nice to discard the banged up old race bike every year.

I've talked to a couple of mechanical engineers about the issue over the years. The first one told me the same story as has been mentioned above: no way is a bicycle going to get soft from use. If anything, it will work harden and get stiffer.

The second one said the same thing but with a twist: he knew what he'd been taught, and he believed it right up until one of his old steel frames started to, well, soften up. Soggy bottom bracket, head tube given to wobble, lack of "liveliness". And he's at a loss to explain it. He's come up with several theories, and he doesn't like any of them. I've had the same experience with a 30 year old frame that had seen a lot of racing, was hung up for a decade and then pressed back into somewhat lighter service. The frame is definitely softer now than it was when I first started back riding it a couple of years ago.

Having said that, I've never known a steel frame to become unrideably soft, unless it was broken. My "soft" frame is still perfectly functional for recreational riding, but when I hammer it at the "race rides" it isn't so good anymore.

HTH!

I thought perhaps my favorite was going soft, then I remembered that the wheels on it were built up 30+ years earlier from USED parts except the nipples. So I exchanged thenm with a "fresh" set, problem solved. Remember a bike is a system.

Good point! I dunno what the exact scenario was regarding the engineer friend, but the frame I'm talking about has been built up several different ways in the last few years, including a bunch of NOS Super Record stuff and Mavic SSCs. I'm confident that I have isolated the problem to the frame, though I'll be darned if I can explain it.

My old frame is not as lively as it was 30 years ago, but my 30-year old bike is doing just fine.