We proudly introduce our redesigned Smartbox software for Harley-Davidson Euro 5+ / R.41.05 models. This intelligent software module controls your Dr. Jekill & Mr. Hyde exhaust system, monitors legality, and elevates your riding experience to the next level. Because the system responds more accurately to your throttle input, fewer valve closures are needed, resulting in a smoother response and a more consistent sound. Thanks to extensive research and valuable feedback from riders, the software is now smarter and better tailored to practical use than ever before.
New: 41.05 Euro 5+ optimization
During the certification of our exhaust systems, testing is done with a constant throttle. However, in everyday riding, you continuously vary your throttle. Our new software compares this actual behavior with the official test method and subtly adjusts the valve control. The outcome: fewer unnecessary valve movements, a smoother response, and a more refined sound without compromising legality.
You will notice the difference immediately while riding: the engine runs smoother, the sound feels more consistent, and your overall riding experience gains an extra dimension. It's a subtle improvement that pays off in increased comfort, more enjoyment, and an even more refined character of your Dr. Jekill & Mr. Hyde exhaust system.
Important to know: Not mandatory, but highly recommended
If you are satisfied with your current Smartbox and sound, you can continue to enjoy without making any changes. However, if you want to maximize The Exhaust experience, the new Euro 5+ / R.41.05 software provides a clear upgrade in smoothness, riding experience, and sound.
Ordering and availability
You can order the new Smartbox through your Harley-Davidson dealer. Systems delivered from September 1, 2025, come standard with the latest software. If you received your system in August 2025, we will exchange the Smarbox free of charge. For all other Harley-Davidson Euro 5+ / R.41.05 models, a new Smartbox costs €169 excl. VAT.
