What are early signs of failure in forks/stem/handlebars?

Question

I ride an SE Lager. In the past year, the following components have worn out or broken

1. Front chainring
2. Rear cog
3. Rear freewheel
4. Chain
5. Seat (one of the bars snapped off)
6. Many, many spokes
7. Wheels

Basically, it seems to be a very cheap bike made to a minimum standard. I like the feel of the bike and with my replacements for the above components I'm pretty happy with the way it rides.

The thing that scares me is that the forks, stem or bars will break and pitch me face first into the road.

How can I tell if these components are also weak or try to detect early signs of failure?

Update: Added wheels as replaced parts

Answer 1

You are well past the point where I would have told you to throw the bike away and buy a decent one. But IME the frame and fork are usually better built than the components on a bottom-of-the-range bike. There's no real corners to cut on a frame and fork, where they can shave component quality endlessly. Well, they can switch to mild steel tubing but that's rare above the $199 price point. You may well find that the only difference between your bike frame and one on a bike twice the price is the paint.

There's no non-destructive way to tell whether the frame and fork will fail that doesn't cost (a lot) more than the bike is worth. Especially since in this case the bike is worth less than the sum of its parts(1). You could try pulling on the frame/fork to see how flexible it is, but that tells you nothing about how likely it is to fail suddenly (unless it fails while you're testing it). Or you could xray it and have a competant metallurgist examine the images for defects (a single rock climbing carabiner can be thus inspected for perhaps $US200, but a bike is a lot more complex).

If you like the feel of the bike try looking for something similar, probably from the same manufacturer. But looking at their site, you have the mid-range model. I suggest test riding better bikes until you find one you like the feel of. Or do what you have done - replace everything on the bike with better components and hope for the best.

(1) you have replaced most of the components with ones bought retail. So you've paid more markup (and probably labour charges too) than if you had bought a bike with those components already on it. You're probably also suffering from the sunk cost fallacy - you've spent all this money and are reluctant to throw it away. I can't make that call for you, but look at what's left of the original bike and work out how much it will cost to replace it all - especially the wheels. It might be cheaper to buy a better bike and strip the current one for spares.

Answer 2

Basically, nothing you've replaced so far is out of the ordinary for a well-used bike, other than perhaps the seat. I've worn out two front rings, two clusters, easily six chains (which I now replace every thousand miles, just on general principle), and at least a dozen spokes (not counting those I've replaced when I relaced "tired" wheels). Replaced entire wheel sets a couple of times. Also, two bottom brackets, three sets of pedals, and a couple of wheel bearings. Never replaced a freewheel, but they do fail on "good" bikes. This would be in maybe 10,000 miles of riding on three bikes. Someone heavier and/or more muscular (I had polio as a child) would likely wear things out about twice as fast as I do, and off-roading in a bike not designed for it will obviously take an early toll on the bike (as will riding a bike clearly meant for a smaller, lighter person).

I have heard of forks failing (rarely), and, unfortunately, there's no reliable way to know if one is about to fail. Some forks are very well built, others not so well, some are built such that cracks will be obvious, others have designs that will conceal cracks. But looking at the picture of your bike it looks like a reasonably good fork design that would not conceal cracks and not be prone to premature failure.

I've never heard of a catastrophic handlebar or stem failure, and I would judge them quite unlikely.

But there does come a time when it's best to retire an old bike and get a new (and hopefully better) one. I wouldn't discourage you from doing this, but it doesn't seem imperative in your case.