Akrapovic Racing Line Stainless Steel Full Exhaust System Honda CBR650R / CB650R (2019-2026) – S-H6R16-HKGKHSS

Four kilograms. That is what this system takes off a Honda CBR650R, and it is by some distance the largest weight reduction on this page — 37.7 % of a standard exhaust that weighs 10.6 kg. The Akrapovic Racing Line (Stainless Steel) S-H6R16-HKGKHSS is an underbelly complete system with the catalytic converter inside the header, and its type approval is explicitly valid for the 35 kW versions, which makes it one of the few full systems an A2 rider can fit and stay legal.

Key Features

• 6.6 kg against the standard 10.6 kg: 4.0 kg removed, a 37.7 % reduction, and most of it from under the engine where it lowers the centre of gravity
• Underbelly layout — the muffler sits below the engine instead of beside the tail, which is what makes the weight saving structural rather than cosmetic
• Supplied as one unit with the catalytic converter inside the header
• Handmade carbon fibre cover with honeycomb exhaust protection and the Akrapovic logo in red and white
• 1.5 PS (1.1 kW) more at 12,000 rpm and 2.3 Nm more torque at 3,500 rpm
• Type approval valid for the 35 kW A2 versions and for the E-Clutch models
• EC and ECE type approved, Euro 5+ compliant, no remapping required

Why the Underbelly Layout Matters

Moving the silencer from beside the seat to underneath the engine does two things a conventional slip-on cannot. It removes mass from high and far back on the machine, and it puts what remains close to the roll axis. On a 650 cc four weighing over 200 kg wet, four kilograms taken from that position changes how quickly the bike falls into a corner more than the same four kilograms taken from anywhere else.

The system arrives as a single welded unit, headers included, with the catalytic converter housed inside the header rather than in a separate mid-section. That construction is what keeps the emissions path intact and allows a full system to remain type approved.

Performance and Sound

Peak power rises from 89.7 PS to 91.2 PS at 12,000 rpm. The torque picture needs stating carefully: Akrapovic records a gain of 2.3 Nm at 3,500 rpm, low in the range, while the peak figure is essentially unchanged at 61.5 Nm against the standard 61.8 Nm. In other words this system fills in the bottom of the curve rather than raising its highest point, which suits a road-biased inline four.

The note is deep and sporty, and the honeycomb screen over the outlet is a functional part rather than a styling one — it protects the exit from road debris on a system that now sits under the engine, in the firing line of the front wheel.

Fitment and Compatibility

S-H6R16-HKGKHSS fits both the faired CBR650R and the naked CB650R from model year 2019 through 2026, and Akrapovic confirms it fits the E-Clutch versions of both. One restriction applies and it is worth reading before ordering: this exhaust system does not fit together with the original Honda under cowl on the CB650R. If that cowl is fitted, it has to come off.

Road Approval

EC type approval and ECE type approval, Euro 5+ compliant, with the certificates supplied and downloadable here. Akrapovic states that the type approval certificate is valid for the 35 kW models, so an A2 licence holder can fit this system to a restricted CBR650R or CB650R and keep it road legal — which is unusual for a complete system and is the main reason to choose it over a slip-on.

Specifications

• Part number: S-H6R16-HKGKHSS
• EAN: 3831126458096
• Fitment: Honda CBR650R and CB650R (2019–2026), E-Clutch versions included
• System type: Racing Line, underbelly complete system, one unit
• Material: high-grade stainless steel
• Cover: carbon fibre, handmade, with honeycomb outlet protection
• Catalytic converter: inside the header
• System weight: 6.6 kg (stock 10.6 kg, saving 4.0 kg / 37.7 %)
• Power: 91.2 PS at 12,000 rpm (stock 89.7 PS at 12,000 rpm, gain 1.5 PS / 1.1 kW)
• Torque: gain of 2.3 Nm at 3,500 rpm; peak 61.5 Nm against 61.8 Nm standard
• A2 / 35 kW: type approval certificate valid
• Restriction: does not fit with the original Honda under cowl on the CB650R
• Remapping: not required
• Installation time: approx. 45 minutes
• Road approval: EC and ECE type approval, Euro 5+
• Country of manufacture: Slovenia