hey simon, an rs 50 restricted will only do 30mph for legal reasons, the same as any other 50cc even though they are capable of more. however when de-restricted the rs 50 will do 60-65mph. so get an rs 50 cos they are fast and fun. every 50cc will be restricted to 30mph when new but when de-restricted are unlikely to go any faster than the rs, so go and buy one if you havnt already!!!