ThundersportGB bosses have released the final series structure for the 2009 season with the addition of a MiniTwins class adding to the recently-announced Thundersport 500s.

MiniTwins will replace the existing GP2 category and is the only major re-think from the series' 2008 debut.

"Having considered many requests from interested parties, ThundersportGB have decided to include MiniTwins in the 2009 Championship. This will run to the existing MiniTwins regulations," said promotor Dave Stewart.

"This class has undeniably got the potential to become a full national championship in years to come and will certainly benefit from the media and TV exposure of the Thundersport GB platform.

"We thank all the other parties who registered an interest in joining our series and wish that we could have accomodated them all. However, we have a standing committment to give a set amount of track time to all of our classes and we were not willing to compromise that principal by taking on too many categories to be able to deliver the quality and value that our members have come to expect."

The series line up is:

Thundersport GP1
Sound of Thunder
Formula 600
Superstock 600
Streetfighter
Junior Powerbike
Thundersport GP3
Aprilia Superteens
Moto 450
Thundersport 500
MiniTwins

For further details, click here. For MiniTwins regulations, click here