A couple of years ago I lamented on Facebook about the unfortunate loss of knowledge seemingly endemic to many bicycle shop mechanics. A friend commented that he refers to the new generation of wrenches as "parts installers" instead of mechanics since many don't actually know how to fix anything.

It's a vicious cycle for sure: shop hires mechanic, mechanic gains experience and knowledge, shop can't afford to keep mechanic, mechanic moves on. This isn't what we're here to discuss, though - at least not today.

Sadly, the "parts installer" phenomenon isn't limited to the retail end of things with much of the consumer base being similarly afflicted. Rather than repair something that isn't functioning properly, the first instinct now is to just replace the offending bit – preferably with something newer, shinier and more expensive, of course.

Creaky bottom bracket? Replace it!

Poorly shifting derailleur? Replace it!

Sluggish suspension fork? Replace it!

Your kid isn't doing well in school? Replace it!

Much as some folks will lambast me for challenging consumerism, the truth is that many things can actually be fixed. You don't need to buy as much as you think you do.

Take, for example, the hordes of Shimano STI Dual Control levers out there. For many of you, this will sound familiar: the action starts to get muddy and shift performance slowly degrades. While the lure of instant gratification and magpie-ism tempts you to replace old with new – and naturally, an upgraded and matching pair – you can easily repair that lever for less than what you just paid for your daily venti soy no-foam macchiato. Simply use a strong aerosol solvent to dissolve and purge the old grease from the shifter guts, repeat as necessary until things loosen up, let it all evaporate, then relube.

Seriously, that was it. But hey, that new Dura-Ace sure looks good on there, as does the matching credit card bill.

Knowing how to fix something first requires an understanding of how it works. In the case of that STI lever, the main lever advances a ratchet wheel to which the cable is attached. As the wheel advances, a small spring-loaded pawl snaps down on each successive tooth so that the spring tension in the rear derailleur doesn't just yank the cable all the way back once you release the lever.

Upshifts are accomplished by pushing on the secondary lever, which releases the pawl and allows the spring tension to return the ratchet wheel one step at a time. On your old STI lever, the factory lube thickened up over the years, eventually overpowering the spring's ability to move the guts. Once you understand this, that fix then becomes obvious – remove the goop and the pawl can move freely again.

The same can be said for just about anything on your bike. As much as bikes can be on the cutting edge, they're still at their essence very simple machines that are also simple to understand if you're willing to investigate a little. Take a moment to figure out how everything operates: when you move that lever, what does it do? What is that cable connected to? What does this adjustment screw move?

Once you know how everything works, diagnosing a problem is relatively straightforward – as should be the required repair.

In fairness, the bicycle industry doesn't always help matters with products that are becoming increasingly non-serviceable. Try actually getting parts for that STI lever, for example. And does anyone else remember the rebuildable pivots on SRAM's original ESP rear derailleur? Likewise, dealer service departments nowadays prefer to send complete replacement components instead of stocking small parts and teaching dealers how to actually service things.

That shouldn't keep you from being curious, however. So by all means, twiddle that knob, turn that screw, take things apart, patch that tube, (I pile them up during the season and repair them in the winter), buy tools, and find out how to use them. In other words, learn something. In fact, it's exactly this unrelenting need to tinker and tune that designers and engineers tap into to improve products from one generation to the next.

Don't dive in blindly, though. Make sure to jump in with the awareness of what effect that change makes and leave a mechanical trail of breadcrumbs should things go awry so you can get back home. A notebook and repair manual can be quite handy.

At the very least, you'll become more in touch with your bike and perhaps gain an appreciation for your local mechanic — assuming they know what they're doing. And if all goes well, you will make your next ride that much better with a finely tuned machine that disappears beneath you – fully satisfied that you did the work yourself and didn't have to bankrupt yourself in the process.

James Huang has been writing about bicycle tech since 2005 and has more than 14 years of experience as a shop mechanic. In that time he's seen plenty of fantastic gear and technology but also a lot of things that have just flat-out pissed him off. Follow the AngryAsian on Twitter at @angryasian, and check BikeRadar for more of his columns soon.