How are they different?

1 LEGALITY

Aftermarket pipes carry the E-mark with a Type-approval certificate from the country they are certified in (the number after the E) if they are road-legal and pass Euro laws, which can be found stamped/etched/riveted on the can and a copy of the certificate is also generally included in the accompanying documentation. Euro5 (which came into force in 2020) has a second-gear drive-by noise limit of 80db (revs depend on bike’s capacity and engine type) and also limitations on emissions

2 CONSTRUCTION

Akrapovic’s can is constructed using a carbon-fibre outer skin and stainlesssteel internal pipework. The pipe is held in place on the bike using a separate carbon support bracket and it fits to OE pipework. The Kawasaki can is made from a stainless-steel outer skin with a metal end cap and stainless-steel internals. It is a one-piece unit and mounts directly to the collector box and has an inbuilt hanger mount

3 WHAT’S INSIDE?

Inside the Akrapovic is a perforated steel-tube core with a sound-deadening ceramic chopped fibreglass wadding quilt around it. The Kawasaki unit uses ‘deflection technology’, a series of tubes and metal baffle plates to deflect and quieten the sound before it exits the exhaust. The bigger the mid-section exhaust box, which generally sits under the motor, the less baffles in the end-can chamber so the smaller the pipe

4 WHY NO REMOVABLE BAFFLES?

Legislation specifies no removable baffles for a slip-on can to be road legal. If they are, the can has to be marked ‘not for road use’ and can’t be E-marked. Akrapovic only makes a road-legal exhaust for the SX whereas it makes non-road-legal ones with removable baffles for other models of bikes, such as sportsbikes

5 AGE MATTERS

If you are adding to an older bike, you only need to meet the Euro standards relevant to that model’s age, which is Euro3 or Euro4 to be road-legal, not Euro5 unless the bike was built in 2020 or after

6 REBUILDABLE

Akrapovic sells a kit to rebuild the end-can, which costs from £80 (it also offers a rebuild service) which should be done every 10,000 miles. The Kawasaki OE unit is non-rebuildable

7 FULL SYSTEMS

More bikes now have one-piece systems with the end-can and downpipes a single unit, so you can’t fit an end can without cutting the OE pipe. Bikes like the MT-09 therefore require a full system and as that means expensive catalytic converters need to be included to meet regulations, the price goes up

8 WHAT’S INCLUDED?

The Akrapovic slip-on exhaust comes with a carbon exhaust hanger, two clamps, spring, gasket and all the necessary fixings to fit the slip-on and hanger as well as full instructions and an E26 certificate. If you are buying a replacement OE Kawasaki end can, you will need to buy the £715.31 can and the £187.87 cover, £117.19 exhaust end-cap and also a £12.46 gasket, bringing the grand total to £1032.83. Interestingly, Kawasaki sells a titanium Akrapovic with a carbon tip for £819.95 that is road-legal and ready to install

9 WHERE ARE THE CATS?

Catalytic converters act as restrictions so if you want power gains, you need to remove them. On bikes like the SX, the cats are in the collector or the pipe leading to it (a de-cat link pipe is needed to remove them) but some have them in the end-can, which is why a slip-on will deliver power gains. However, unless the slip-on has cats in it, it will not meet Euro5 regs, making it illegal in Europe despite passing a UK MOT