Description
French tuning expert Bidalot launched their 2018 Bidalot Exhaust RF50WR Derbi. This high-end racing exhaust was specifically developed to go with Bidalot's 50cc RF-WR cylinders.
The expansion chamber is hand-made, the 0.8mm thin cones are laser-cut, each cone is then rolled and TIG-welded manually; the welding seams are smoothed to get rid of any bumps and burrs. The black carbon silencer comes with a "Bidalot" logo. Since this is a state-of-the-art high-end product, materials and manufacturing quality are beyond any reproach.
The performance of this masterpiece is through the roof, especially when combined with the matching cylinder. Output is fantastic throughout the entire powerband, it starts with impressive torque at low rpm, never lets up and really shines at high rpm. Best combined with the RF-WR 50cc racing kit.
All the small parts needed for installation are included. A 4-hole flange for the RF-Wr cylinder is part of the kit, too. The two mounting brackets have to be welded onto the chassis for perfect fit.
- for Bidalot RF50WR Racing cylinder
- low mount, Derbi
- 4-hole flange
Bidalot Racing Factory
Bidalot has been known for 50cc tuning and racing components for several decades. The Racing Factory series (RF WR) includes Bidalot's high-end products and is the brand's most powerful series to date.
The series is available for various displacement classes. The Racing Factory products go to the absolute performance limit in all categories.
Racing Factory range
You can equip your bike completely with Bidalot Racing Factory parts and build yourself a high-end racer. Here is a list with Racing Factory parts:
- Cylinder Bidalot RF WR 50cc to 96cc
- Crankshaft Bidalot RF
- Bidalot RF internal rotor ignition
- Clutch Bidalot RF
- Exhaust Bidalot RF
- Gearbox Bidalot RF
- Spare parts Bidalot RF (gaskets, pistons, clutch plates...)
Of course, you need a bit of know-how to install the racing parts correctly and adjust them to yield maximum power.
To get the full potential out of your engine, we recommend buying a high-quality carburetor with the right diameter for the selected displacement.
Also remember to adapt the chassis to the increased engine power, e.g. with improved brakes and suspension.
Exhaust scooter, moped, motorcycle
The exhaust has a major influence on the performance of scooters and mopeds. By replacing the original with a tuning exhaust, you can improve the gas flow and increase the engine power.
exhaust parts
- The headpipe or header is the connection between cylinder and exhaust, and an exhaust gasket provides the necessary seal. In street-legal systems, the headpipe is equipped with a legally required restriction. Some people remove this restrictor to increase power.
- The actual exhaust body or expansion chamber is connected to the header pipe. In a classic 2-stroke expansion chamber type exhaust, gas pressure waves are used to improve engine performance.
- At the end there us the silencer or muffler that discharges the exhaust gases and, with the help of damping wool, also reduces the noise generated by the vehicle.
Replacing the exhaust
As a general rule, please check if the exhausts fits BEFORE REMOVING THE RESTRICTOR, otherwise the exhaust cannot be returned.
For 2-stroke engines, various settings and components usually need to be adjusted when the original exhaust is replaced with a tuning version. These changes include:
- Adjusting the carburetor by replacing the main jet.
- Upgrading the clutch or replacing the clutch springs.
- For scooters, it may be necessary to reduce the weight of the variator weights.

Tuning Level: High End racing
We categorize our products into different performance levels Original, Sport, Racing and High End , so that our customers can choose the right parts for their setup. It is really important to combine parts that belong to the same tuning level, this is especially true for cylinders, crankshafts and exhausts.
High End Racing products are exclusively designed for racing and should only be handled by tuning pros with the appropriate technical know-how. High-end racing parts often require modifications or machining of certain elements to accommodate the often larger components (larger crank webs, larger intake, etc.). Whether you stick with 50cc or increase the displacement, high-end racing parts offer much higher performance than the original parts and are the most powerful tuning parts.
Note: To ensure the reliability of the engine, it is important that the parts are compatible and that you do regular maintenance on your two-wheeler.