denaffen

If you can repair a sewing machine, I'm pretty convinced you could repair about anything. Those things make most bicycles look like ox-carts.

As for bikes, I'll repeat what others have said. Get your hands on some raggedy bikes. They should be free or near free. Tear them down, clean, polish, lube and rebuild. You'll learn a ton, and get good pretty quick.

Also, for anything that's even slightly complicated, lay the pieces out in order, including facing the right direction, and take *lots* of pictures. Even when you've been doing this a long time it's easy to get things backwards sometimes, and that will cause lots of problems. Even the dreaded 3-speed hub isn't all that bad, if you just pay attention to how it went together in the first place (and take those pictures).

bikemeister

I've been working on my own bikes since I was a kid in the 60's. My dad wouldn't fix my bike, so, I had to learn to do it for myself.
Stopped riding once I got a car, and it wasn't until maybe the mid 80's that I took up riding as a hobby. By 1990, I realized if I was going to repair bikes (for myself and others), I'd have to learn the advancements that had occurred from say 1970 to 1990. I turned to bike magazines, and took a couple of months going to the local main library as they had back issues of mags.
That brought me to the (then) present. 1990 Most bikes I work on now use the technology that I know ( steel and aluminum frame, freewheels, early index shifting, etc). Although the past 10 years the technology has again eclipsed my knowledge, so, if I were going to get into cycling maintenance heavy duty I'd have to re-educate myself again.

Atlas Shrugged

Don’t forget YouTube it’s all there.

SurferRosa

Buy a mid-level vintage road bike and refurbish it. This includes a full overhaul, replacing parts with period correct items, replacing consumables where needed, and polishing components. Buy low, sell high. Do it again and again.

davidad

As an adult I started riding in 1990 at the age of 47. I began working on my bikes almost from day one. I bought a Huffy mountain bike from K-mart and was surprised at the price. Boy was I in for a shock. I couldn't get comfortable on it, even going so far as putting aerobar s on it trying for comfort. You should have seen the looks at the bike shop when I told them what it was going to be used on. The a used Raleigh at a local hock shop that I had overhauled at a local shop. When I bought the Giant 980C I was a bike junkie. With it and the Raleigh I began working on my bikes. In the refinery where I worked I was give a 28 hole SA hub. I bought a rim and spokes and built my first wheel. The spokes wee too short but the wheel held up well. It was on a Schwinn beach cruiser that I carried tools and fittings in the refinery.
I bought a Trek 5200 in 94' and rode it until 2000 when I bought my first of two Herons. For those I bought frame and fork, built the wheels, and built up the bikes with a mix of shimano parts and Campy brake levers.
After I retired I began being the mechanic for a group of old farts who rode in our area.
I have never been afraid to take something apart and I will find the info I need, at first at the library and then on the web.
I have not seen much of the electric shifting mechs. and wouldn't bother learning them anyhow. I see no real value in them.
So, if you want to learn how to work on a bike there are schools or you can just jump in and have a go. The bike is still a simple device to work on if you want to or need to.

wrenchwench90

A funny development; I received a sewing machine for Xmas from my partner's mom, and I was so excited that something might be wrong with it, (singer Merritt 2404 that she got for a deal) of course it's in great condition and runs well. Looking forward to learn all about that as well