New exhaust regulations in 2025 affect motorcyclists – who is really behind them?

When regulations are more important than driving pleasure

Since March 2025, new regulations for retrofit silencers on motorcycles have been in force in Europe. The decision stems from the 80th session of the UNECE (United Nations Economic Commission for Europe), where international regulations No. 41 and 92 were revised. The aim is to make it more difficult to increase the noise level of motorcycles beyond the legal limit by removing dB killers.

Who is behind it?

An international collaboration between political and economic actors is responsible for the new regulation:

1.  UNECE – United Nations Economic Commission for Europe

• Headquarters: Geneva
• Official initiator: 80th meeting of the GRBP (Noise & Tyres) expert group
• Task: Development of technical vehicle regulations – including Rule 41 (vehicle noise) and Rule 92 (retrofit mufflers)
• Validity: Not only in the EU, but also in Switzerland, Japan, South Korea, and parts of the USA

2.  WP.29 – World Forum for Harmonization of Vehicle Regulations

• UNECE Technical Working Party
• Responsible for the worldwide recognition of vehicle standards
• In March 2025, the new rule was officially validated here.

3.  ACEM – Association of European Motorcycle Manufacturers

• Headquarters: Brussels
• Members: Harley-Davidson Europe, BMW Motorrad, Ducati, Honda, KTM, Yamaha, among others
• Objective: Uniform and legally compliant retrofit solutions in accordance with UNECE type approval to relieve manufacturers of liability risks.
• Role: Active co-developer of the new rule

4.  IMMA – International Motorcycle Manufacturers Association

• Global representation of the interests of the motorcycle industry
• Participation in an advisory capacity during development

The EU Commission also plays a key role, as it supports implementation at the national level. In Germany, the issue falls under the remit of the Federal Ministry of Digital and Transport (BMDV).

At first glance This seems like a well-coordinated measure by all parties involved. However, from the perspective of many motorcyclists—myself included—another question arises:

Isn't this overregulation?

Of course, tampering with exhaust systems is nothing new. DIY instructions on how to remove dB killers to make bikes sound more powerful have been around for years. The fact that this is not officially permitted is also nothing new. But instead of monitoring and taking targeted action against offenders, the entire motorcycle community is now being held accountable.

The new rules will make it difficult for retrofit manufacturers to offer customizable, legally usable exhaust systems in the future. Individuality is being stifled—and that in a scene that thrives on precisely that.

Why do associations go along with such rules?

1. Industry wants predictability and consistency

ACEM members such as Harley-Davidson, BMW, Honda, Yamaha, and others want to clear, uniform framework conditions, to market their products Across the EU and internationally without having to contend with 27 different national regulations.

Example: Better to have a uniform UNECE rule for the whole of Europe than different decibel limits, TÜV requirements, or road closures in each country.

2. Protection against uncontrolled growth in retrofit products

Manufacturers have been annoyed for years about „Cheap accessories“, that:

• does not undergo any real tests
• easy to manipulate (e.g., dB killer with Allen screw)
• causes complaints, damage to reputation, and approval problems

The associations' goal: Better a controlled, certified retrofit industry, which is included in the type approval – even if it means less scope for customization.

3. ACEM does not want blanket driving bans

ACEM and IMMA see what is happening in Tyrol, the Black Forest, and Lake Garda: Driving bans from 95 dB, in some cases also for road-legal production bikes. ACEM thinks strategically: If we get involved early on, we can binding technical solutions offer – instead of politicians simply closing routes.

4. Political pressure & „green acceptance“

The motorcycle industry is under pressure: EU emission targets, CO₂ fleet regulations, Euro 6e, e-fuels vs. electromobility. For many, compromising on noise regulations is a kind of „political fig leaf“, to prevent stricter bans in other areas. Better to help shape your own solution than to have to put up with one imposed from outside., one could say, to put it simply.

More consideration—but at what price?

Of course, motorcycles should not be a source of disturbance. But it is also important to consider how many people are affected by these new regulations, while the origin of the debate is often limited to a few hotspots in the Alps or suburban areas. Instead of regulating with a sense of proportion, restrictions are now being tightened across the board—with the argument of „wanting to make the roads quieter.“.

Impact on you as a driver:

Does grandfathering apply to existing exhaust systems? Yes—grandfathering generally applies! If your exhaust before entry into force the new regulation was legally permitted, you may continue to use it.

However: You may have it. do not change (e.g., remove dB killer), otherwise the operating license will expire → this may result in Fine or shutdown come. The problem is not the old system – but rather a changed Appendix.

What are the consequences of tampering or noise pollution?

If you have an exhaust system illegally modify or louder than permitted, the following may occur:

• Fine of up to 80 euros (in the case of noise pollution)
• Decommissioning of the vehicle (in the event of loss of operating license)
• TÜV summons or defect card

Bparticularly strict Controls are in place, for example, in Tyrol, South Tyrol, the Black Forest, the Lech Valley, and in cities with noise action plans.

Customization is restricted—but not prohibited

Correct: The new rules make it more difficult to customize retrofit exhaust systems. Manufacturers must adhere to strict specifications. Plug-and-play systems with easily removable dB killers are effectively no longer eligible for approval.. However, you can still install exhaust systems., if they comply with the new regulations – many providers such as Jekill & Hyde, KessTech, or Penzl are already adapting their products accordingly.

Penzl offers, for example, the Elo conversion kit, which allows mechanically adjustable PM exhaust systems to be converted to electronic control. This system is suitable for motorcycles with CAN-BUS or diagnostic connectors from Harley-Davidson and has EC type approval. 

Why was the whole thing initiated?

1. Increasing complaints from the population

• Many citizens—especially in tourist regions in the Alps (Austria, Germany, Switzerland, Italy) – have complained about loud motorcycles
• In places like Seefeld, Kochel, Lechtal, Timmelsjoch, or Tyrol already existed Driving bans for stationary noise levels above 95 dB

2. Political pressure from environmental organizations and local authorities

• Examples: German Association of Cities, VCD, BUND, Noise League
• These groups have raised noise as an environmental problem—similar to particulate matter or CO₂.

3. Technical advances in mufflers

So authorities ask: Why tolerate manipulation? Today, the industry can build quieter exhaust systems without at least some loss of performance.

My opinion!

And what about the roads themselves?

In my opinion, potholes, bitumen strips, and roads with speed limits of 30 km/h for motorcyclists only, which have not been repaired for years, are much louder than any exhaust pipe. Safety begins with the condition of the road. Anyone who travels frequently and extensively will quickly notice that the focus is often no longer on the essentials.

Instead of bossing bikers around over a few decibels, it would be better to ensure that roads remain safe to drive on—for everyone. The fact that some sections with poor road surfaces are more reminiscent of off-road tours seems to have slipped far down the list of priorities.

The new anti-tampering regulations for exhaust systems are a further step toward greater regulation in the motorcycle sector. Anyone who is heavily involved in customizing will feel the impact of this. Whether the measure will actually lead to greater peace and quiet across the board—or simply restrict individuality and riding enjoyment—remains to be seen.

What we need instead is a fair balance: consideration, yes, but please with a sense of proportion. And above all: investment in safe and functional road infrastructure—instead of constantly adding new rules on paper.

Text & image: Harleysite – Errors and changes reserved.

---