If you want a mountain bike for trials, I would suggest any bike under 25lbs with non-curved tube frame, under 14 inch frame size.
No.
Yes, if you can find the correct bottom bracket for the frame.
I would suggest a bike with a small frame and a long seat post if you want a low seat for jumping, but a larger frame if you ride mountain and street more.
Well, the most common one would be carbon fibre, but there are several other composites that could be used.
not all are. if you want to do dirt jumping i recommend you do not use a normal mountain bike. get a proper dirt jump bike. i used a felt q520 xc bike to dirt jump and the forks broke and i took it in and the mechanic said i had damaged the frame and it was close to snapping.
Yes you can but, depending on your frame, you'd need a shim to get the post to fit your frame.
For bike frames titanium can be used unalloyed.
A mountain bike is made to be ridden on rough terrain so it has tough, knobby tires; a heavy, strong frame; and shock absorbing features. A street bike is designed to be ridden or smoother surfaces, therefore it has smoother tires, a lighter frame and lower handle bars so you can see hazards more easily.
A mountain bike is basically a bike meant to be strong enough to be ridden off road. It's overall stronger and has wider tires than other bikes. Montague Paratrooper Mountain Bike is a bit special in that the frame folds in the middle, making for easy storage and transportation.
The best bike frame is the bike frame u truly believe in
It's a bike frame that measures 18" from center of bottom bracket to top of seat tube. 18" would be just a tad shy of mid-sized.