I currently have a Univega Rover 100 (I have no idea if this is a "good" bike or not, but it's served me well for 12 years). I want to ride my bike more towing my two little boys in the bike trailer we have. I got a flat tire the other day (the tire itself has a gash in it, somehow), and the gear shifting is a little funny, and it seems like the brakes are never aligned right (they always rub on the tires a little, even when I'm not using them). I never cared that much when I was just riding around town by myself, but when I'm pulling 65 pounds uphill everything gets more annoying. :-)
Anyway, I'm wondering if I should throw any more money at this bike, or if I'd be better off getting a new bike. I could spend up to $300. I'm not very well-versed in all the bike lingo, so I don't even know if I would want a "hybrid" or "comfort" or "road" bike, or what. The two bikes I'm kind of looking at right now are a K2 Big Easy Deuce ($289 from REI) or a Schwinn Traveler ($219 from Costco). But maybe my current bike would just be fine; I don't know! I want something that would be good for riding uphill, since I live in a hilly area, and we have lots of thorns, too (it's the desert), so maybe I need special tires for that. Any ideas?
As I recall, the Uni Rover 100 was a pretty low-end bike--but so are the two you've mentioned as possible replacements. The Costco Schwinn is almost certain to disappoint you, I think. I don't know much about that specific bike, but I've looked at Costco bikes in general, and they're usually badly assembled, even to the point where they wouldn't be safe to ride, and if you have a problem, I don't think they'll help (Costco is good on returns, but they're not set up for bike service).
REI has a better rep, especially if your store has a bike shop (not just a sales rack), and that's a good price on the K2 (checked it on the website). You'll be comfortable on that pedals-forward frame, too (that design has a name, but I can't remember what it is...). Of the two, I'd recommend that.
Assuming there's nothing major wrong with the Rover, though, you can probably put it into decent riding shape for @ $100. A few suggestions:
New tires, maybe $25 each. Just get used to flats--they're part of cycling. With practice and a decent pump, you can whip out the old tube (to patch later) and put in a new one in about three minutes. Something like Slime (a sealant in the tube) can cut down on the numbers, but you'll never get rid of them. Buy tires to ride, not to stop bullets. And if you'll be mostly on pavement, don't buy knobbies--tell the guy in the shop you want road tires, something around 1.5 inches wide or so.
The shifting and brake adjustment problems are probably just that--adjustment problems, fixable in a few minutes by anybody who knows how. You can learn (it's not hard), or you could pay a shop a few dollars for a tune-up (I have no idea how much--I've done all my own work for years--but I'd guess less than $50). You should also pull out and lubricate (or replace) the brake and shift cables, which sounds intimidating but isn't hard. That will make a big difference in the feel. And lubricate the chain with something oily--they make chain lubes, but ordinary oil will work well enough. Flow it on, then spin the pedals backward and use a towel or rag to wipe the excess off (it will take awhile).
More complex jobs include putting in good aftermarket brake pads, but that can wait. Usually, when you resurrect a cheap old bike like that that hasn't been ridden much, the main issues are sloppy assembly to begin with coupled with a decade of no maintenance. Both are easy to fix.
As for riding hills, look at the gears on the crankset, the ones down there by the pedals. For hills, you want to shift into the SMALL gear there, and the BIG gear in the cluster of gears on the back wheel. That's your lowest gear, and it's made for hills.
There are kevlar tires that resist punctures pretty well but the best thing you can do to prevent flats is to watch where you are going and to always make sure the tires are properly inflated.
Your local bike shop can tell you if it's worth fixing up your old bike or not. I imagine some maintenance and a tune-up will do wonders.
As for the other two bikes, they are on the low end and will likely need a bit more attention paid to them regarding adjustments to keep them running smooth.
Since you live in a hilly area, you should pay attention to the gearing of any bike you might choose to purchase. A triple set of rings in the front will give you more low gears for those hills. Also, for the rear gears, the bigger the number, the lower the gear. (eg. a mountain bike cassette could be a 12-34, meaning it has a 12 tooth cog and goes up to a 34 tooth cog. Most road bike gears in the back are 12-25) For the front rings, the lower the number, the lower the gearing. A triple crankset may typically be 53-39-30 or 48-36-26; depending upon the bike.
Hybrids typically have road bike wheels with fatter tires, a front suspension fork, upright geometry, and maybe a suspension seatpost and/or an adjustable stem to move the handlebars front or back. Generally, you have to dismount the saddle to have your feet touch the ground. IMHO, the suspension fork isn't needed unless you are jumping off curbs. The ride is comfortable, you can pull a trailer. The gearing is usually wide enough to climb anything while still being fast enough on the flats.
Comfort bikes are like the K2 Big Easy Deuce. The saddle has you way back on the back wheel, the pedals are forward, the geometry is upright, and you can put your feet on the ground without leaving the saddle. Slower than a hybrid, the ride is comfortable, especially if you have back problems. Again, they usually have that worthless front suspension which just adds weight and robs power but you aren't riding a comfort bike in a race.
The K2 is a comfort bike. The ride will be comfortable and smooth, thanks to the fat tires and front suspension and upright geometry. It'll be slow, too.(I'm comparing the ride to a typicaly road bike) Gearing is low enough to climb walls but the geometry is less efficient but you'll still be able to pull that trailer. Components are on the very low end; I expect you'll need to be vigilant in keeping things adjusted properly to keep the bike running smoothly. I'm guessing you ride recreationally a few miles at a time so you should be okay though I'd save a few more dollars and get something better from Giant or Trek.
The Schwinn Traveler is very similar in design to the Giant FCR or the Trek FX but the components are very low budget. It should be faster than the K2 due to its larger wheels, thinner tires, and more aggressive geometry.
If you do get one of the bikes you mentioned, please take them to a bike shop to make sure everything has been assembled correctly and is properly tuned.
The Trek Pure is a comfort bike that is fun to ride and should be in line with what you are looking for.
7.2FX is similar in style to the Schwinn but a much nicer(and more expensive) bicycle
My wife had a hybrid but she outgrew it; it was too slow for her. She loves her 7.5FX
Check with your bike shop about tuning up the old bike first. If it turns out to be unsalvageable; please consider spending a bit more on a new bike. You'll love the ride so much better, you will ride more and farther.
IMHO. no matter if you fix up the old bike or buy a new one, in your area, many have went with the extreme tire setup...Armadillo tires, tire liners and heavy duty and/or slime tubes. Yes it adds some weight, but it helps cut down on flats in the desert environment.
Most, if not all, low cost bikes need their wheels trued and the spokes properly tensioned at minimum. Then you have the brake and derailleur(s) adjustments. These are extra costs that most buyers aren't aware of, whether it's a new bike or an old one. I don't find fault or criticize ones choice or having a limited budget...your old bike served you well for 12 years and the post above says it was "pretty low end bike"...so low cost doesn't necessarily translate into the bike falling apart in a few months. If you can't afford more than $300, then it becomes a debate whether or not to fix up the old bike or buy a new one. If you have to replace or service a lot of the parts on the old bike, it might be better to just buy a new one since the costs may end up the same. You didn't mention if you regularly greased, oiled, changed chains, etc etc on your old bike...so there may be excessive wear on many parts if you rode it a lot.