I am a female..and although I'm all for girl power I need a light bike for easy transport. I plan on using it for leisurely cruises and occasional hiking/bike trails. What type of bike should I invest in- the most I'd like to spend is 250- steel or aluminum?
Aluminum is lighter but some bike companies are designing frames with cromoly / steel that is light, they make the frames thiiner but strong to close the weight of an aluminum frame. Try to canvass first to reputable bike shop, they will assist you on your needs. Beware of some Bike dealers that the only thing in mind is just to sell w/o assisting you properly.
For weight savings, go with Aluminum, it is lighter than the steel, by a significant margin. That being said, steel will give a more supple and more pleasant ride. Aluminum bikes often can have a harsher ride due to the rigidity of the frame, just a characteristic of the metal. So there are trade offs for each variety. Personally, I have a few bikes, and when I go for long rides, steel is by far my preference over Aluminum. I don't think you can go wrong with either, they both just happen to have their own distinct advantages.
Go to a local bike shop, tell him you want a hybrid, and you got $250 to spend. They might make you a special deal on one. A hybrid is a cross between a mountain bike and a road bike. Great for leisurely cruising and light off road. If you have no luck with the LBS, go to a box store and try to find a Schwinn hybrid in the right size. They are good bikes for the money. If they won't let you ride it around before you buy it, make sure there'll be no problem with returning it if it doesn't work for you, and that they've got somebody to make minor initial adjustments after you've ridden it a day or two. Later, the LBS will be glad to fix 'bout anything that'll go wrong with it. While you're at it, buy a floor pump to keep at home for airing the tires. Sizing is VERY important. Be careful about that.
Have you considered going to a bike shop and looking at hybrid or commuter bikes? These will fall into price range (ie. KHS, Fuji,etc.). Aluminum is generally lighter than steel but the components can make difference in the weight too. Go with a bike shop that way you will be buying from people who know what they are selling. A chain like Performance Bike is a good way to go. The prices are right and you can get a much higher quality bike for your money than you'll find at a department store, plus they give lifetime free adjustments and tuneups.
Wrong wrong wrong WRONG. If you are looking at bikes in your price range aluminum and steel will weigh the same... it is possible that the aluminum will even weigh more! It is a fact that aluminum is 1/2 the weight of steel but it is also 1/3 the strength. The only way to build a cheap aluminum bike frame is to make the tubing larger and thicker... more material = more weight. What's worse id that cheaper aluminum frames do not hold up very well so in comparison the steel frame would be the better choice. Now, if you were to consider high end bikes, I would say that steel tends to be lighter than aluminum and approach the weight of titanium.. but we are talking $2000-$3000 frame-only.