Type of cycle for losing weight and staying fit for a beginner Over a year ago I was diagnosed with a collapsed arch in my left foot and despite trying many times I have not been able to get back on the treadmill. I have been thinking of getting a bicycle to start losing the weight that I have put on. I currently weight 240 lbs. I have a couple of questions:


Should I get a hybrid bike or a mountain bike or a road bike? I have read conflicting views on what is better for weight loss and general fitness.
Should I buy a geared or a non-geared bicycle?


I am not looking to become an expert rider and would probably only ride 3-5 times a week. I just need something that will get me a bit of fresh air and help me loose a bit of fat.
You want a geared bike -- not necessarily 50 speeds, but at least 3, preferably 15 or so.  If derailleur-style bikes scare you, there are geared hub bikes available (though they tend to be a bit more expensive).  (But, honestly, there's nothing to be afraid of with a modern derailleur-style bike, if properly maintained.)
If you're only going to be riding on roads and paved trails (which is most likely the case, at least first year or so), the type of bike makes little difference, so long as it fits you appropriately and is comfortable to handle.  (Though at your weight a "full suspension" bike is probably not a good idea, and, in general, even front suspension is not of much use on roads).
Mainly you should pick a bike that fits you well and is comfortable.  You need a 10-20 minute ride to really check this out, and any bike shop that won't let you do that (within reason) you should avoid.
Be wary of the handlebar.  Most bikes are delivered with the handlebar too low, and modern "threadless" front bearing setups require adapters to raise the handlebar to an appropriate height.  Make sure you get the handlebar height set appropriately before you leave the shop, and go back if it seems to need changing.
Be wary of the seat.  Many "comfort" bikes (which are worth considering) will come with an enormously wide seat, which may seem wise at the beginning but quickly chafes the inner thighs.  You don't want super-narrow, but likely not super-wide either.  (Of course the seat can be changed fairly easily.)  And, while purists sneer at gell-filled seats, they can be more comfortable for rides of intermediate length (over an hour, say), so long as they're not too "squishy".  Stay away from the pillow-like foam seats, however.


And do get a comfortable helmet (be wary of those with a large visor in front, they often obscure the vision), and whatever lock seems appropriate for your area/needs.  And be sure to get a light set if you ever ride at night -- nice LED light sets are now available quite cheaply.  

As for shoes, usually a pair of athletic shoes is good for starters -- just avoid anything that's too wide due to lots of extra rubber on the sides of the soles.  Or an old pair of leather shoes will work for starters.  With your arch problem it's probably best to avoid anything with a too-thin, too-flexible sole, but hard-soled bike shoes are probably unnecessary, and could be counter-productive.  (I have polio-weakened ankles and arches and I biked for decades (including several multi-day tours) in plain old "tennis shoes".)

The shop where you buy the bike should give you a free tuneup after the first month or two.  Discuss this when you buy the bike.  If you buy a used bike from a private party most shops will do tuneups for a very nominal fee, often free, just to encourage your business.