As fast as a bike.
how fast does 250cc Orion dirt bike go
How fast does a Coleman 100 cc 2 stroke mini bike go
A pocket bike can go up to 45 to 125 km
it all dipends on the bike
not very fast
55 to 60 its fast
totaly depends on what bike it is a i have a 50cc twist and go that does 66mph my friend has a geared bike that does just about 70 soo if you get the right bike it can be pretty fast