The Thunderbird Twinspark will be the first model to feature Royal Enfield’s revolutionary Unit Construction Engine.

All the well loved features of the Thunderbird have been retained and enhanced in some cases. Also, the twin benefit of improved performance and engine efficiency makes this motorcycle hard to beat in terms of pure riding pleasure and visual delight. The evolutionary mix of old and new features in this motorcycle will surely delight its owners.

http://royalenfield.com/Motorcycles/thunderbirdtwinspark.aspx