I was wondering I am 6ft tall and was wondering what size Mt bike should I get and what is a good bike just to start out with off road and rocky and sandy trails. Thanks again, see ya on the trail.
Sizing a mountain bike really depends on a few more things than just height. Standover, frame geometry, and type of riding are also important factors. Also, different manufacturers size their bikes in different ways. In other words, a "large" from one company may not necessarily equate to a "large" from another. The best thing you can do is go to a reputable dealer in your area and have them size you for a bike. Before you purchase, you should also check to see if any companies offer "demos" to ride, so you get more than a "once around the parking lot" feel for your new bike.
If I were you I would ask cyclist in your area for a reputable bike shop (you can do a search online for biking groups in you area). With your new list I would call around to find the bike shop that has a trained Specialized "FIT" specialist. It is hard to say what size bike you need without talking proper measurements and trying you on different bikes. Anyway, that is where I would start. Good luck!!
Buy an MTB yet? I'd be interested to see what you bought and the why's of your purchase. If not, I see that you are in a rocky and sandy location. If you are in the desert southwest or an equally "rugged" location with plenty of ups and down, I would steer you toward a full suspension (FS) MTB. The terrain is just too unforgiving for most anyone, nonetheless a beginner, in my humble opinion. The brand is not as important as being happy with your purchase. You will spend near $1000 for a good quality MTB though you could find last years model at a good discount. You need to pedal around the parking lot or even rent a bike to see what works for you. What's important in a FS MTB is the "bob" effect of the rear suspension. Duriong pedaling on flat or uphill surfaces, the bike will "bob" up and down during the pedal stroke. Good bikes are designed to limit this "bob" either by design or with an adjustable rear suspension that, with a flick of a lever, can limit or turn off "bob". You will be very satisfied with any of the major brands on the market. Stick with a local bike shops or go to the internet if you know what you are looking for. Many off-brand bikes use the same geometry and suspension from major manufacturers (horst, DWlink, and others license out their designs) so you can get an MTB priced well below name branded ones. I test rode at least 10 different brands (Trek, Cannondale, Specialized, Yeti, Giant, Santa Cruz, Ellsworth, and Intense before settling on a Turner Burner). If you aren't in a rugged area, I'd go with a hard tail with a nice front suspension fork. FS bikes have limited application in nice rolling, root strewn, sandy areas that aren't covered with the crazy rocks and descents we have in the desert southwest. Plus, FS bikes are heavier. Overall, the benefits of a FS bike in terrain not necessitating FS goes largely unused. For your height, you might consider a bike with 29" tires. Your height would work well with the larger tires. Again, you have to test ride to find your bike. Be confident that your local bike shop (LBS) won't sell you a bike that isn't your size- they want your business when it comes to word of mouth and maintenance. Try different sizes too. A Cannondale x-large might fit you better than a Trek large. Also, you can size up your bike, but not size it down. By this, you can swap the stem and adjust the seat post to size the bike to your height and reach. But, if the bike is too big, you will have to suck it up. Don't ignore used bikes either. Check Craigs LIst; folks are looking to sell their bikes on this free on-line community. Ask the seller to have your LBS check it out first. If you buy from the internet, your LBS will usually assemble it for a nominal fee- well worth the cost for someone who doesn't know how to adjust the brakes, cable, gears, etc...
Geometry has to do with the actual frame dimensions including the length of the top tube and seat tube, and the head tube angle, amongst other things. When you put a Trek and Cannondale side-by-side (or as many manufacturer's that your bike shop might have), you can see that the bike's angles are not the same. The front fork of one bike might be closer to the down tube than the other; the seat might sit over the pedals of one bike instead of leaned back; geometric differences that are popular today whereas when most of us growing up (I'm 48), the bicycle was triangular shaped. So, you might find a Cannondale medium more comfortable than a Trek large simply because the geometry. Bottom line is whatever fits you best and is more comfortable regardless of size, is the bike for you because like bikes, people are different. My arms might be shorter comparative to my legs, therefore, brand X might fit you better.
Great post lik2bikarmy! I couldn't agree more and this took me a while to figure out. I had a Haro Escape for almost 10 years that I got used to riding which was stolen. I started looking for new bikes the same size but each one I tried just did not feel right even with the same frame size. I tried Specialized, GT, Giant, Schwinn, and even new models of Haro and each one of them felt different. I finally settled on a Trek 4500 which had the most similar feel to the Haro because of the geometry of the frame and not just the frame size.
For off road bikes, go for full suspension mountain bikes they are heavier and more expensive than hardtail bikes, but it has both rear and front shocks making them ideal for technical single track.