Whatever you do, DON'T buy your bikes from Wal-Mart, Target, K-Mart, etc. Choose a reputable bike dealer. They will ensure your bike is built properly, show you how to use it, and provide service after the sale.
We just bought my MIL the Trek Navigator as well. The Navigator comes in 2 different levels. The 2.0 and the 3.0. The primary difference is compontery. It also comes in a women's specific model with the lower top tube to make it easier to step into.
If your just going to pedal around the campground/park, I wouldn't get much more than the Dahon 6 speed folding bike. Not overly expensive and they fold up pretty small. Not the best bike for any longer rides unless it is flat and smooth.
Lots of other good suggestions, but they sound like overkill for what you stated was your riding purposes. It always seems like we are trying to be oversold on things, no matter what our intended use for it is going to be. I guess the flip-side is that you could go for a bit better quality just in case you do get more serious with where and how you want to ride. Always the dilemma!!
Ron & Carolyn
Sadie the Irish Terrier
Happy the Lakeland Terrier
From sailing yacht to land yacht
KE7BZC
M/V Lothlorien GO HUSKIES
We had two aluminum frame foldables from Wal-Mart for 125 bucks each. Both had front and rear deralleurs by Shimano. Great bikes-better than Dahons at less than half the price. Special order at Wally-World.
We tried the folding bike option also. Bought two from Camping World for $149 each. They are 6-speed and we have about 350 miles on them now. We have been amazed at how well they ride and how much we like them. My wife thinks she may never ride her regular bike again. They work well, have comfortable seats and have a lower center of gravity so make her more confidant. We store them inside so don't worry about vandalism or getting them wet or full of road grit. We sometimes ride 20-25 miles per day and can't think of anything we would change about them.
Several years ago I ask the same question. We had a couple of folding bikes we always took with us, but never seemed to ride much, and we decided we wanted full size bikes to ride at the campgrounds, ride to the store occasionally, and maybe once in a while explore the area on them. It was recommended we visit a bike shop, which is what we did.
I told the Bike Shop owner our plans, we wanted nothing fancy, but I did not want them to rust, I wanted brakes and gears that worked, and finally a comfortable seat. We ended up with a pair of Fuji Comfort Bikes which I believe we paid around $350.00 each. The bike shop fit the bikes to us, and gave us a couple of free future tune-ups.
We ride a lot more than we planned and even ride the some at home. I strongly agree with the folks telling you to go to a real Bike Shop. It has really paid off for us.
One more thing to consider is the beating the bikes take while hanging on the back of the rig on a bike rack. Rain, dirt, oil, salt (if you do any winter or spring camping), rocks thrown up by cars, etc., take a toll. You can keep them covered, but now you're talking tarps, cords and ropes, etc. I tried bringing them in for travel, but didn't like wet, dirty bikes inside. As someone else mentioned, it depends on what you're going to use them for before you decide whether you only need cheap transportation, or better quality touring bikes.
Another vote for the folding bike option. We bought a pair of Avenir (made by Dahon) aluminum 20" 6speed bikes. Like another poster, I may not ever ride my mountain bike again. Very comfortable. I like the way my handlebars are higher than on my mountain bike. Much better and more comfortable. Pick a seat that is comfortable for you and you can always change from the one it came with if you need to. They fold up as small as the average folding bike and came with carrying bags. Paid $400. each tax everything included. It would have been another $200. per bike if I went with the Dahon brand name stamped on and yet I have Dahons. I believe each region gets a rebranded Dahon called something else. Here in Canada, ours is Avenir. I think the States have the Yeah. Not sure. Good luck with your quest.
TH, TW, Son & Daughter
2006 Dodge Ram 2500 HD QC 5.9L Turbo Diesel
2009 Forest River Wildcat 29RLBS
I had a Dahon folding bike, and my big arse has gotten too heavy for the wimpy handlebar neck it has... (I'm 5'11 and weigh 220lbs). I bought a Revive 8 speed by Giant. It is the most comfortable bike I've ever ridden, with a backrest on the seat, and everything is adjustable. It has a real gooseneck, yet it folds down quite a bit-not in half like the Dahon, but a good amount nonetheless. It feels much more solid on some of the gravel "roads" in campgrounds, I don't worry about it breaking apart under me. My only real gripe with it is that it won't sit on a standard bike rack. It stays chained to the coach when not in use, and in the back of the toad when I'm moving.
Pup: 2007 Jayco 1206 w/slide-out + shower
surge brakes, 54w solar panel
TV: 2005 Nissan Xterra 4X4, manual trans
25 years tent camping, 4000+ miles of hiking, lots of biking