Help Me make a good choice...
 

Trek MT 220 (7 years)
GT Ricochet (19 years)
Raleigh Venture 3.0 not sure how old
Several Schwinn Bikes too.

Using it on the road, maybe trails & to the gym and home -a couples miles a day. Haven't used a bike since I was a teenager but if it works out I'm open to increasing its use and making it a primary source weight loss exercise. I'm almost 6 ft tall 200lbs moderate shape.

Not the Trek MT 220, that's not the frame for you,

I don't know your budget, BUT IMHO bikes older than 5 or 6 years tops tend to become harder to find parts for and are almost never worth upgrades.
Putting a set of tires~n~tubes on, truing a wheel or two, replacing even ONE cable and a chain will most likely cost more than you paid for the bike.
The cost of the used bike and the cost to, "bring it up' Is often very close to a GOOD brand's new bikes at the level you seem to need..

My Standard advice to people who are coming to or back to bikes like I did,,sounds like you are,, Is simply this,,

Don't buy from the big box stores at the mall and NEVER walmart,
Buy only from a good Local Bike Shop and NOT the Internet as you will need LOCAL bike shop support, This I promise you :P

Your first bike will not be your last and you will know what you need by the time you want a second bike....


Bikes are a way of life,,no, scratch that, a way to live for many of us,,these are the type of answers you will often encounter..

I've yet to see a $150 used bike that did not need another $100 plus,,
another $100-$150 gets a warranty and a SHINY new paint job !!
If you get there when they take it out of the box you may even get a whiff of that new car smell,, Remember ?? :P

Wow.
 

Thank you for such a passionate response!

I agree with osco53, you would better buy not so old bicycle like 5-6 years old.

I disagree. First of all, what parts do you imagine would not be available after only 5-6 years? Derailleurs, brakes, headset, what? Surely you're not talking about tubes and tires, cables and chains. Parts availability is NOT going to be a problem.

Second, when you consider what used bikes sell for on Craigslist, you will end up with a much better bike if you are willing to buy one used and then replace/upgrade as needed. You don't say what your budget is but you will be able to afford a much better machine if you buy used, especially if all it needs is tires, cables, maybe new brake pads, chain, etc.

5-6 years old is practically a new model, and all you need to consider is the condition of the specific bike you're looking at. I would not consider age at all. Look at the configuration. How many speeds? Are those parts still available (cassette, derailleurs, shifters, etc.)? What kind of brakes (cantilever, V-Brakes, caliper, etc.)? Does the bike you're considering have any special, proprietary parts? Probably not.

For the same amount of money, would you rather have a brand new Chevy (with a warranty) or a 5-year-old Mercedes with 20k miles that only needs a set of tires, new windshield wipers, and an oil change? If you buy the Chevy, the warranty will run out in a year and then you'll still be driving a Chevy instead of a Mercedes.

The advantage of a new bike (as stated, from a LBS and not a big-box store) is they offer "free tune-ups" for some period of time. But you're going to learn how to work on your own bike, I assume. It's more trouble and takes more time to drag a bike to the store to adjust something than it is to do it yourself.

Buying used does require a bit more savvy, so you know what you're looking at and whether it's worth putting money into. On the other hand, buying new from a bike store is a no-brainer, you just go in and buy what you like.

So what IS your budget?

The only parts you "might" run into problem with are rear suspension parts and if you have bike the manufacture doesn't support anymore for some reason a lot use standard bearings. Breaking a linkage or swingarm though could be the end if you can't find a used replacement. Older bikes are more likely to have straight steerers and highend replacement forks are getting hard to find with straight steerers. If you go with a 26er new highend 26er wheelsets are getting harder to find, forks are really hard to find. Nice QR wheelset are also a bit of pita to find but a lot can still be converted to QR so not a huge deal. Went through that probably two years ago for my 2011 29er and even today that ancient full suspension bike is still worth upgrading/repairing.