Well my take is this, The better quality of the component parts means less tweaking. That doesn't always mean the most expensive, and hardly ever means the lightest, but a good, well built dérailleur is going to stay in adjustment better than a poor one. You can go the "Dutch" route, and buy a Bakfiets, but riding that on a 20 mile commute might be a bit tiring.

Secondly, power losses on a car are hard to notice, and have only an indirect impact, "Why is my fuel consumption so high these days?" On a bike, your legs tell you about every watt you expend, you feel every "grind, grind" every poor shift, and so on.

I ride a 10 year old bike, I don't think it's ever been cleaned. The first 2 years were spent riding, but the next 6 were basically sitting in a garage or shed. Now I have it out again. But still, although there are minor problems (rear der. can't get into lowest gear, probably a dirty cassette, and recently front der. was having problems getting to lowest as well, but i suspect it's the deraileur itself), it rides alright for the most part. That's all that matters to me, for it to run. Maybe if I have time, I'll flip the thing over and give it a nice clean up, but I've been telling that to myself for the past 6 months.

It's how people perceive the maintenance of the bike. Some wish it more, some less.

I oil my chain every few weeks/whenever it needs it and top off the tired every other day.

Other than that, I only work on my bike when it needs it.

You'd be amazed at how better the bike rides with a non-gunked up chain and cassette. I let my road bike get a little dirty over the last year...it was night and day after giving it a good cleaning in early spring.

Anyway, I only do minor amounts of tweaking on my bikes...I check the tire pressure almost every time, and periodically clean and lube the chains, make sure the brakes aren't rubbing, make sure my cleats are properly secured. A few times a year I do a good chain/gear cleaning, tune the deraileurs and do a good once over on the bike.

Not too different than my car: check my tire pressure, wash and clean it every few weeks; at regular intervals I check my fluid levels and change my oil; I get a tune up and alignment probably once a year.

Basic maintenance will keep any piece of equipment running well for a long time...I like prevention.

Its not that bicycles need more tweaking, its that motor vehicles don't get enough.

If a motor vehicle's tires are low one just needs to push the gas a bit more and it takes a bit more fuel - a difference hardly any one will notice. A cyclist can feel the extra resistance from a soft tire and would rather take the time to keep tire inflated to keep the bike as efficient as possible.

I'd wager than there is a significantly higher percentage of under inflated regularly used motor vehicle tires than regularly used bicycle tires.

(all the above similar for transmission/drivetrain, suspension, alignment, etc.)

Al

They don't (unless its a MTB that sees serious use in sand, mud, cowcack etc)

If you want a bike that needs almost no tweaking, first, get at least a internally geared hub. I personally recommend SRAM as my top choice. I have (or had) many of them, and to me they are my favorite. I especially recommend the iBrake on their model. You fix both the maintenance and the tweaking issues at once. No rim degradation, not prone to being hit like a disc brake and good rain performance. My roommate has the SRAM S7 with the ibrake that I mounted for him. Impressive! It hasn't went through a whole winter yet so I can't say about its water-proofness and resistance to corrosion.

Fenders (especially those made of steel or aluminum), chain guard (hard to find) are also a good idea.

You should of course have it maintained (or maintain it yourself) once a year, but two is better if you ride where there is snow (once after winter, and once before). Most importantly, do your maintenance after winter, since it's the season during which your bike will get beaten most.

Alu over steel for your frame is a good idea. But if you're like me and you think nothing rides like steel, rustproof your frame. Gotta make some compromises.

I was complaining about having to fix something all the time the other day. I generally like working on stuff but I too would like to ride my bike more than work on it.

Lots of you are missing some basic point in the differences

Lets say your chain, BB, crank, RD, FD, and cassette were all self lubricated AND enclosed within a aluminum casing.
Now lets say your wheels (hubs & axles) were sealed from the elements and lubricated.
Then lets say instead of mounting to a dropout/hanger, your RD is a very robust thing that never moves - only the internal parts move. And the internal parts move in a very different way than a RD.

Now how much less maintenance would you need to do...
That's why a car can go 3-10,000 miles between any maintenance - its systems are protected from the outside world and always lubricated properly. The design on the transmission is very different than a bike's transmission.

That's a bit extreme. However, I found that fenders and a long front mudflap do a lot to keep the drivetrain clean.

Even though I commute daily (about 18 km each way, which often extends to 25-30 km) in all sorts of weather, I typically clean the chain about twice a year. Brake pads need to be changed once or twice a year also. As for the rest, I need to readjust my shifters about once every two years.

I oil the chain about once a week, and clean it about once a month. (It's needing it right now.)
Top off the tires just before each ride because I notice a real difference between fully-pumped tires and slightly soft ones.

Unless something breaks, so far, that's it.

I have a loose fender that I aim to properly secure in the next week or so, but that's because I never completely finished its original installation 9 months ago.

you are lazy

I tend to agree. My commuter was made with sealed Phil Wood hubs and BB, and the maintenance over the last 20 years has consisted of changing chains, adding lubrication and replacing the RD when it failed, and replacing the freewheel as it wore. And lots and lots of tires. I'm still using the same Campy FD but the Campy Chainrings do need replacement now. Believe it or not I have not changed the cables or the heavy duty KoolStop brake pads in all that time. (the pads are well worn and due for change). I did replace the rear wheel about 4 years ago as the rim slowly failed from cracks around the spokes.

The BB failed back about 7 years ago when the spindle split in half from corrosion... not bad considering that I rode though several flooded roads back in the 80s.

I am about to tear the whole thing down and have all the bearings replaced and powdercoat the frame. (if the internal rust isn't too bad)

Well over 20 years with minor repairs for a daily rider ain't bad. I've toured with that bike, and rode it nearly daily on and off since about '84.

I didn't bother with daily "tweaking," I just rode the thing into the ground... and missed all the changing technology that came along since... what is this index shifting so many speak of? Brifters??

To add to that, I have a skinny tire bike that I use for fun rides... it does need a tweak every couple of hundred miles... usually minor stuff like derailuer adjustment or cable tightening... and of course weekly oil and cleaning. About once a year I do break that bike down and repack all the bearings... a vast difference from what I do to the commuter.