This is a heavy duty replacement flywheel rotor for the Aprilia 1000 cc V4 engine. The original Mitsubishi flywheel fitted to these machines uses a low quality epoxy to secure the magnets to the rotor body. Over time, and over repeated heat cycles, that epoxy loses its grip. A magnet works loose inside a spinning rotor, and what follows is rarely limited to a charging fault - a detached magnet can take the stator, the cover and in the worst cases the engine with it.
The usual home remedy is to prise the magnets out and re-bond them with marine epoxy. That approach causes as many problems as it solves: magnets end up out of alignment or incorrectly spaced, replacement magnets of the wrong grade are used, the epoxy chosen is not formulated for the temperature and shear loads inside a running engine, and any oil contamination left on the rotor body prevents a proper bond. This unit is the alternative to that repair - a complete new rotor, built with an improved epoxy, high grade steel capping over the magnets, and precise balancing, and it is covered by a two-year warranty.
Key Features
- Heavy duty replacement for the original Mitsubishi flywheel rotor
- Improved epoxy specification to retain the magnets
- High grade steel capping over the magnets
- Precisely balanced
- Addresses the known loose-magnet failure on Aprilia 1000 cc V4 engines
- Two-year warranty
Technical Specs
| Specification |
Detail |
| Exterior diameter |
115 mm |
| Interior diameter |
108 mm |
| Interior diameter, centre housing |
16 mm |
| Exterior diameter, centre housing |
24 mm |
| Thickness, exterior |
30 mm |
| Thickness, interior |
33 mm |
Vehicle Fitment Guide
| Make & Model |
Years |
| Aprilia RSV4 1000 Factory |
2009-2012 |
| Aprilia RSV4 R 1000 |
2009-2012 |
| Aprilia Tuono V4 1000 |
2011-2012 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 857201 |
Aprilia |
Frequently Asked Questions
Does this flywheel need any modification to fit?
No. It is a direct replacement for the original Mitsubishi flywheel rotor on the listed Aprilia models and uses the standard dimensions - 115 mm outer diameter, 16 mm centre housing bore - so it fits the factory taper and cover clearances without alteration.
What is included?
The heavy duty flywheel rotor itself. No other components are supplied with it, so reuse or renew the crankshaft nut, key and cover gasket as your workshop procedure requires.
How can I tell that the original flywheel has failed?
The warning signs are a rattle or knock from the alternator side of the engine, erratic or lost charging, and metallic debris found in the engine oil or on the sump plug magnet. If the cover is removed, loose, cracked or displaced magnets inside the rotor confirm it. Because a detached magnet can wreck the stator and the crankcase, the fault should not be ridden on.
Why not simply re-glue the magnets in the original rotor?
Because a re-bonded rotor rarely holds. Removing and refitting magnets by hand leaves them misaligned or unevenly spaced, replacement magnets are often not of the correct type, general purpose epoxies are not formulated for the temperature and shear inside a running engine, and residual oil on the rotor body stops any adhesive keying properly. This unit is built with an improved epoxy, steel capping over the magnets and proper balancing, which is why it carries a two-year warranty.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
