PearTune MSO Tuning Chip — The Safest Kit for Shimano EP801 & DJI Avinox
PearTune is a Czech manufacturer with one decisive advantage: Chip Lock, a technology that makes the kit completely invisible to workshop diagnostic tools. It is also the only safe hardware tuning option for the Shimano EP801 motor — and one of the few kits covering DJI Avinox. The MSO range also supports Bosch Gen2–Gen5, Yamaha PW-X3/PW-S2, TQ HPR, and Giant SyncDrive.
View PearTune on Amazon£149-249→Our PearTune MSO verdict
⚠ Shimano EP801 owners — critical warning before buying any tuning kit
The Shimano EP801 (DU-EP801) is fundamentally different from the EP8 (DU-EP800). Internal signal-freeze kits — SpeedBox 1.3, VOLspeed — trigger error E295 on first detection. After four detections: E299 — permanent motor lock, reversible only at an authorised Shimano dealer at significant cost. Warranty voided with no recourse. (The external BadassBox 4 is safe on EP801 — no electronic motor contact.)
Only safe options for EP801: PearTune 3.0 EP801, BadassBox 4, MBIQ-P (Damp mode), EPAspeed 1.2. If your bike has an EP801, do not install any other internal kit.
PearTune MSO — compatibility by motor
| Version | Install type | Speed display | Detection risk | Price (approx.) | Buy |
|---|---|---|---|---|---|
| PearTune MSO 3.0 Still On | Internal (wired) | Real speed ✓ | Very low | £149-169 | Buy → |
| PearTune MSO 4.0 V2 | Internal (wired) | Real speed ✓ | Very low | £169-199 | Buy → |
| PearTune MSO 5.0 Remote | Internal (wired) | Real speed ✓ | Very low | £209-249 | Buy → |
| PearTune MSO 4.0 TQ (roadmap) | Internal (wired) | Real speed ✓ | Very low | TBC | Buy → |
| PearTune 3.0 EP801 | Internal (wired) | Real speed ✓ | Very low | £169-199 | Buy → |
| PearTune MSO DJI Avinox | Internal (wired) | Real speed ✓ | Very low | £209-249 | Buy → |
PearTune Chip Lock: how the anti-detection technology works
Chip Lock is PearTune's most important engineering contribution to the tuning market. Most kits on the market simply go "inactive" when you deactivate them before a service visit — but inactive does not mean invisible. Motor firmware logs can still record speed anomalies from previous rides, and some diagnostic tools can detect the presence of a spliced connector even when the kit is off.
PearTune Chip Lock goes further: when engaged, the module simulates a completely standard motor signal chain. Diagnostic software connected by a workshop technician sees behaviour that is indistinguishable from a factory-stock motor. Speed logs, sensor readings, and connector state all appear normal. Activating Chip Lock takes a few seconds via the bike's native buttons — or instantly with the MSO 5.0 remote.
Active mode: the module intercepts the bottom bracket cadence signal and adjusts the motor's speed reference, extending assistance beyond the legal threshold. Real speed is displayed on your console. Chip Lock mode: the module simulates a completely unmodified motor — no anomalous readings, no log traces, no detectable splices. The transition between modes takes seconds.
PearTune MSO range — which version to choose?
Installation guide — PearTune MSO 4.0 (5 steps)
- Identify your exact motor reference: check the label on the motor case — EP801 vs EP8, Bosch Smart System BES3 vs Gen4 vs Gen5 are not interchangeable. Order the wrong version and it will not fit.
- Gather tools: Torx T25 and T30 keys, a clean work surface, and the PearTune installation guide for your motor (available on the official PearTune website).
- Open the motor case: remove the 4–6 Torx screws on the motor housing. Place the cover on a cloth to avoid scratching the finish. Note the cable routing before disconnecting anything.
- Connect the PearTune module: the kit is a Plug & Play inline connector — insert it between the cadence sensor connector and its original socket. Route the module inside the case avoiding any pinch points before closing.
- Close, test, and configure Chip Lock: refit the motor case, power on the bike, and run the activation sequence from the PearTune guide. Test tuning mode, then practice the Chip Lock sequence so you can activate it quickly before any service visit.
PearTune vs SpeedBox — which should you choose?
Recommendation: if you own a Shimano EP801, PearTune 3.0 EP801 is the only hardware tuning option that does not risk permanent motor damage — do not consider anything else. For DJI Avinox bikes, PearTune is similarly the only viable option. For Bosch Smart System or Yamaha motors where detection discretion is a priority, MSO 4.0 V2 is the better choice over SpeedBox. If a lifetime warranty matters more than Chip Lock, SpeedBox remains the alternative on compatible Bosch and Yamaha platforms.
PearTune vs SpeedBox vs BadassBox
PearTune MSO FAQ
What is PearTune Chip Lock and why does it matter?
Why is PearTune the only safe option for the Shimano EP801?
Which PearTune version do I need — MSO 3.0, 4.0 V2, or 5.0?
Is PearTune compatible with Bosch Gen2 and Gen3 motors?
How do I activate and deactivate PearTune MSO 4.0?
Does PearTune work with DJI Avinox motors?
Ready to choose your PearTune kit?
Confirm your motor reference (check the label on the motor case) and order the correct PearTune version. Off-road use only — Highway Act 1988: 15.5 mph limit on public roads.