Depending on how it is geared around 70 mph.
With stock gearing around 50 mph
About a litre
6
i have a xr 100 r its big and fast. i like it
100 mph
it will go 70mph. check on www.topspeed.com.
The best dirt bike for a would be a Honda CRF 100 for a male and a CRF 70 for a girl. Of course the real size of the bike depends on the size and experience of the rider.
90 mph
Probs about 60 - 70 mph
Honda xr/crf 100 would be better.
CRF is just a label used by Honda in classifing the type of bike. for example Honda has lots of crf's. 50, 70, 80, 100, 150, 230, 250, 450.
I have a cr 125 and it goes like 90kph a 250 easily goes over 110kph Depending on the pipe and stuff and engine quality. Over 100 kph definitely