An XR 100 is what i learned to ride on. Then switched to a CR 80R. Wow, huge difference! The XR was great to learn how to ride on, and to jump and balance and stuff. The CR was alot taller, extremely fast and jumps like the wind. The CR 80R went about 75 mph. The XR was less than 50. You will grow out of the 100 really quick, but it is really reliable and takes no maintenance. A great starter bike. The CR race bikes take alot more maintenance, but the performance is amazing. The powerband of the CR kicks in like a ton of bricks and pulls a wheelie through the first 4 gears. The hard part is learning to control the ON/OFF demeanor of it's power. There's no happy medium, it's wide open throttle or no throttle. A 125 is a nice upgrade from 80. IMO.