an exercise bike would be the best start
who was the first dirt bike rider
any body that can ride a dirt bike safly and good
a 105 pound kid should get a 800cc Honda supercharge
Dirt Rider magazine said that the dirt bike of the year was, KTM 350 SX-F
to start of with a50cc
Depends on how tall you are. I would probably say a 250 cc for your weight, but it is a lot of power. Do you have any experience riding?
depends on how tall you are, im guessing that your probabally around 5' 8"-10"? someone like that who is a begginer should try out a Honda XR100
The top speed for a Kawasaki KX125 is about 70 miles per hour. That would be the speed with a 150 pound rider.