Fun Never Sounded This Good
The Speed Twin is a modern classic with a sharp edge, quick steering, real agility, and a parallel twin that rewards a firm wrist. Dr. Jekill & Mr. Hyde builds electronically adjustable exhaust systems for it, with three selectable sound modes controlled from the handlebar, available in street-legal configurations where applicable.
One exhaust, three personalities. In Dr. Jekill mode the valve stays closed for a refined, discreet note, right for early starts, residential streets, and long days in the saddle. Dynamic mode opens the valve halfway for a deeper tone with a harder edge. Mr. Hyde mode opens it fully and lets the parallel twin say everything it has to say. You choose per situation, at the press of a button.
Every system is developed for one motorcycle rather than adapted from another. The Speed Twin system is built around the bike's own lines and mounting points, the result of German engineering and Dutch craftsmanship, so it reads as part of the motorcycle rather than an accessory bolted onto it.
Dr. Jekill & Mr. Hyde electronic valve technology lets you adjust the sound on the fly. One premium exhaust system, three distinct personalities, full control from the handlebar. Backed by a 4 year warranty.
2019 And Newer
Speed Twin
The Valve
In Dr. Jekill mode the valve stays shut and the Speed Twin keeps its voice down. A six in the morning cold start, a quiet street, the ride home well after dark, all of it handled without turning a single head.
The Exhaust
The Speed Twin has never been a bike that shouts for attention. It earns it in the corners, with quick steering, a low center of gravity, and a parallel twin that pulls harder than the classic styling lets on. What it deserves is an exhaust that can match that range.
The electronic valve does exactly that. Dr. Jekill mode keeps it closed and quiet. Dynamic mode opens it halfway for a fuller midrange with real presence. Mr. Hyde mode opens it fully and lets the twin run. All three from a button on the handlebar, changed on the move, without stopping.
Premium materials throughout, a finish built to take weather and heat year after year, and a 4 year unlimited mileage warranty behind it. Available in street-legal configurations where applicable, and on supported stock setups no fuel tuner or ECU flash is required.
Available For, 2019 And Newer
Speed Twin
Sound Check
Headphones or a good speaker recommended.
In Stock Now
What you see here is what we hold on the shelf, ready to ship today. It is one of several ways this system can be built.
The full range of options is available to order. Choose your model, your finish, and your end cap, then see the whole system come together before you buy.
Configure Your ExhaustWhy Sound Control Matters
A loud exhaust is great right up until it is not. Dr. Jekill & Mr. Hyde gives your Speed Twin a hard, throaty voice when you want to be heard and a civil one when you do not, and lets you move between them from the handlebar without stopping.
Leave at five in the morning or roll in after midnight without announcing it to the whole street.
A bike you commute on should not wear you out. Keep it closed and the miles stay easy.
Bike night, a busy high street, the lot outside a cafe. Some places call for presence, some call for restraint.
Then you find the road you came for, press the button, and the twin sounds the way it always should have.
Triumph Speed Twin FAQ
The answers riders ask most often about Dr. Jekill & Mr. Hyde adjustable exhaust systems for the Triumph Speed Twin.
This system is built for the Triumph Speed Twin, 2019 and newer. It is developed for that motorcycle specifically rather than adapted from another model in the range.
Triumph has offered the Speed Twin name across more than one displacement and updated the bike along the way, so confirm your exact year and model in the configurator before ordering. Not certain which one you have? Send us a message and we will confirm it with you.
On supported stock configurations, no tune, fuel tuner, or ECU flash is required. The system is developed around the factory setup of the motorcycle.
Already running other performance parts, like an intake or a fueling mod? Check with your mechanic or shop first, or reach out to us and we will help steer you the right way.
Absolutely. The valve position can be changed at any moment, and you can ride in whichever sound mode you like.
Move between Dr. Jekill, Dynamic, and Mr. Hyde straight from the handlebar control, keeping things quiet when you need to and opening up the note whenever you want to.
Our Speed Twin systems are electronically adjustable exhausts available in street-legal configurations where applicable and engineered to work with the motorcycle's stock setup.
Local rules on street legality vary by where you live and ride, so it is worth checking the requirements in your area. Not sure? Get in touch before you order and we will help point you the right way.
Every system is fully plug and play. No cutting wires, no splicing. Printed instructions ship in every box, and the full set is available online whenever you want to read ahead.
For a capable mechanic it is a straightforward job. The exact time depends on your tools, your experience, and the condition of the bike.
Dr. Jekill & Mr. Hyde® systems are premium exhausts, built on serious engineering, quality materials, exact fitment, clean finishes, and electronically adjustable sound control.
Every system is developed for one specific motorcycle and built with advanced parts, including an electronically controlled valve that delivers multiple sound modes at the press of a button.
That control is the thing a permanently loud pipe can never give you. Slip quietly through neighborhoods and noise sensitive areas, sidestep a costly citation, and stay on good terms with the people you live next to. Then the road opens up, you press the button, and the tone comes with it.
This is more than a muffler. You are buying premium engineering, advanced technology, model specific development, real everyday flexibility, and a 4 year warranty.
