We have the car for the special purpose of a Bobby Car race (is it really!) Bought (for our 12 year old daughter), converted in accordance with the permissible rules and went off the post. Unfortunately we had overlooked the fact that this car has the standard Whisper what the rate decreased, so we the Classic wheels are upgraded for the next time. In normal everyday use for infants Whisper these are but certainly better, precisely because not so extremely fast. At the race (downhill - and locked / secured - street) were achieved with the Classic wheels partly speeds up 72 km / h - which have all Bobby Cars but endured without any problems. Therefore, 5 stars for the good workmanship and good material. Even 18 year old went with it, the cars had no problem with it ... that's saying something ...