State 1 – Tuning active
Splug attached
The magnetic dongle sits on the holder and tuning is active. Intended for use on private property or in appropriately authorised competitions.
Splug – Magnetic E-Bike Tuning Dongle
Exclusively at EBikeTuningShop
Splug – Magnetic E-Bike Tuning You Can Remove
Attach it: tuning on. Remove it: back to stock.
Splug is the magnetic e-bike tuning dongle by MountainTuning. The entire tuning logic sits inside the removable dongle – not inside the bike.
The dongle attaches and detaches magnetically in seconds. Only the holder and the cable harness remain on the e-bike.
Developed in Germany. Available exclusively at EBikeTuningShop.com.
Splug attached – tuning active
The Splug concept
One dongle. One move. Full control.
Splug combines the flexibility of a removable tuning dongle with a magnetic connection.
01
Magnetic and removable
Attach and remove in seconds – no screws, no clips, no cable ties on the dongle.
02
Tuning you can take off
Attached, tuning is active. Removed, the bike returns to stock and assistance cuts off at 25 km/h again.
03
Three modes, no app
Splug for Bosch offers three operating modes, set with a few wheel movements – no app, no PC.
04
Pocket-sized
Once removed, the compact dongle fits easily in a pocket or backpack.
05
Built for the trail
Fully potted dongle and a weather-resistant magnetic connector, designed to hold in wet conditions and under vibration.
06
Developed in Germany
Splug is developed by MountainTuning and available exclusively at EBikeTuningShop.com.
How it works
Attached or removed: two clear states.
The complete tuning logic sits inside the magnetic dongle. Whether tuning is active depends only on whether the dongle is attached.
Good to know
Back to topThe holder and cable harness contain no tuning logic – everything that changes the bike's behaviour is inside the dongle. Remove the dongle and the stock state is restored.
Magnetic mount
Snaps on by itself. Comes off in a second.
The magnetic connector is what sets Splug apart. Earlier dongles used 3.5 mm jacks or USB-A plugs. Splug uses a robust, weather-resistant magnetic connector (Splug4).
How the mount works
A cable harness with a holder is installed once on the e-bike. Bring the dongle close to the holder and strong magnets pull it into place – tuning is active immediately.
To deactivate tuning, simply pull the dongle off and stow it away.
Advantages of the magnetic design
- Attaches in seconds
- Removes in seconds
- Self-aligning, clean positioning
- Fully potted, water-tight dongle
- Designed to hold in wet conditions
- Designed to hold under vibration on the trail
- Compact enough for any pocket
The Splug family
Which Splug fits your e-bike?
Splug is available for several drive systems. Choose the version for your motor – and, for Bosch, your preferred mounting position.
Splug for Bosch Smart System – Frame
Magnetic Splug dongle for Bosch Smart System with the holder mounted on the frame.
Compatible up to and including Bosch firmware 21.12.0
View frame versionSplug for Bosch Smart System – Handlebar / Display
Version for mounting near the handlebar or display, with a 100 cm cable.
Compatible up to and including Bosch firmware 21.12.0
View handlebar versionSplug for Shimano EP8 / EP800
Magnetic tuning dongle for the Shimano EP8 and EP800 drive systems.
View Shimano versionSplug for Yamaha PW-X3 / PW-S2 & Giant SyncDrive Pro2
Splug dongle for Yamaha PW-X3 and PW-S2 as well as Giant SyncDrive Pro2.
View Yamaha / Giant versionSplug for Panasonic / Flyer
Magnetic tuning dongle for Panasonic and Flyer systems with a 2-pin connection.
View Panasonic / Flyer versionSplug replacement dongle
Lost your dongle or need a second one? The holder stays on the bike – just order the dongle separately.
View replacement dongle
Which version is right for you?
Back to topWhat matters is your drive system and, for Bosch Smart System, where you want to mount the holder. Each product page lists the exact specifications of that version. Bosch owners: run the quick check below first.
Compatibility check
Does Splug fit your Bosch e-bike?
Splug for Bosch fits the Bosch Smart System (also called BES3 or Gen4 2022) and Bosch Smart System Gen5 (from 2024, often called CX Gen5) – if all points below apply.
Your bike needs
- ✓Bosch Smart System or Gen5 (square charging plug)
- ✓Classic spoke magnet with speed sensor on the rear frame
- ✓Bosch firmware up to and including 21.12.0
Not compatible
- ✕Bosch e-bikes with ABS
- ✕E-bikes with a rim or valve magnet (sensor inside the motor)
- ✕Older Bosch Gen2, Gen3 and Gen4 with round charging plug
Quick test: look at your charging plug
* provided the bike has no ABS and no rim/valve magnet. If your Bosch e-bike has neither plug, it is either not a Bosch or an older Gen1 (Classic Line).
Bosch firmware updates
Only install Bosch updates up to the confirmed version (21.12.0). Wait for newer versions until we have confirmed compatibility. Never update with the dongle attached.
Bosch dealers often install updates automatically during a service – mention this before every inspection.
Still unsure? The Bosch Tuning Finder checks your system in a few steps.
Back to top
Settings – Bosch Smart System
Three operating modes. No app, no PC.
Splug for Bosch works out of the box. If you want more control, choose an operating mode with specific wheel movements when switching the bike on – the spoke magnet is moved past the sensor. Programming is optional.
Factory setting
Tuning always on
Speed limit lifted while the dongle is attached. Delivered with maximum supported speed.
Mode 2
Tuning always off
Assistance up to 25 km/h and correct speed display – even with the dongle attached.
Mode 3
Decide at switch-on
Tuning activates only if the magnet sits in front of the sensor for at least 4 seconds while you switch the bike on.
Adjustable maximum speed
The maximum supported speed can also be set with wheel movements. All steps are described in the manual (PDF).
Honest note on the display
With tuning active, the Bosch display shows the real speed only up to just below 25 km/h (around 22 km/h as delivered, adjustable). Above that the value freezes, and the odometer no longer matches the real distance. No hardware tuning for the Bosch Smart System can show the real speed above 25 km/h. Tip: use GPS on your smartphone in a handlebar mount.
Installation
Install once. Attach whenever you want.
The cable harness is plugged into the speed sensor line inside the motor compartment – no extra power supply and no other connectors are needed. Example: Bosch Smart System, frame version.
1Open the motor cover
Remove the plastic motor cover – on some bikes a crank arm has to come off first.
2Plug in the harness
Connect the Splug harness between the speed sensor cable and the motor.
3Fix the holder
Route the thin cable out of the motor compartment and fix the Splug4 holder to the frame with cable ties.
4Close and attach
Refit the cover, attach the dongle – done.
Tools you may need
- Torx or Allen key for the motor cover
- Crank puller (depending on the bike)
- Side cutter for the cable ties
Not comfortable with this? Any bike workshop can do the installation.
In the box (Bosch frame version)
- Splug dongle
- Splug4 holder with cable harness (approx. 100 cm)
- 1 Splug cover
- 6 cable ties (2 long, 4 short)
- Manual (PDF)
Other versions: see the product page of your version.
In use
Switch tuning on and off – deliberately.
Whether tuning is active depends only on whether the dongle is attached.
1Attach
On private property or at an authorised competition, attach Splug. Tuning is active.
2Remove
Before you leave that area, pull the dongle off. The bike is back in its stock configuration.
3Stow
Put the dongle in your pocket or backpack. Without it, assistance cuts off at 25 km/h.
All benefits
Why Splug?
Magnetic handling, removable tuning logic and versions for the most popular drive systems.
- ✓Magnetic tuning dongle
- ✓Attached = tuning active
- ✓Removed = back to stock
- ✓Removable in seconds – no tools
- ✓Signal-based tuning principle
- ✓Three operating modes without an app (Bosch)
- ✓No extra battery or power supply
- ✓Designed for wet conditions and vibration
- ✓Bosch: compatible up to firmware 21.12.0
- ✓Bosch, Shimano, Yamaha, Giant, Panasonic / Flyer
- ✓Replacement dongle available separately
- ✓Developed in Germany, exclusively at EBikeTuningShop
Frequently asked questions
How does the Splug dongle work?
Splug processes the signal of the speed sensor. The complete tuning logic is inside the magnetic dongle: attached, tuning is active; removed, tuning is off.
What happens when I remove Splug?
Tuning is deactivated and the bike returns to its stock configuration – motor assistance cuts off at 25 km/h again. Holder and cable harness stay on the bike but contain no tuning logic.
How quickly can I remove the tuning?
In a second: pull the dongle off and the bike is back to stock. No tools, no app, no settings needed.
Does the magnetic connection hold in the wet and on rough trails?
The dongle is fully potted and the Splug4 connector is weather-resistant. The magnetic connection is designed to hold in wet conditions and under vibration.
Which e-bike systems is Splug available for?
Bosch Smart System and Gen5 (frame or handlebar version), Shimano EP8 / EP800, Yamaha PW-X3 / PW-S2, Giant SyncDrive Pro2 and Panasonic / Flyer (2-pin).
Is Splug compatible with the latest Bosch firmware?
Splug for Bosch Smart System is compatible up to and including Bosch firmware 21.12.0. Please install newer Bosch versions only after we have confirmed compatibility. Splug does not fit Bosch e-bikes with ABS or a rim/valve magnet.
Why does my Bosch display stop at around 22–25 km/h?
To keep the motor assisting, Splug holds the speed signal below 25 km/h for the Bosch system. The display therefore freezes just below 25 km/h and the odometer differs from the real distance. Use GPS for your real speed.
Do I need an app or a computer?
No. Splug works out of the box in the factory setting. Optional settings on the Bosch version are made with wheel movements when switching the bike on.
Can I order a replacement dongle?
Yes. The holder stays on the bike, so you only need a new dongle. Order the replacement dongle here.
Where can I buy Splug and which countries are shipped to?
Splug is available exclusively at EBikeTuningShop.com. Orders ship to most EU countries; customers in Switzerland use a separate shipping service. Currently no shipping to France, the USA or Canada. Details are on the shop's shipping page.
May I ride on public roads with Splug?
Not with Splug attached. Tuned e-bikes are not permitted on public roads. Please read our warnings and observe the laws of your country.
Exclusively at EBikeTuningShop
Ready for Splug?
Pick the version for your drive system and order it at EBikeTuningShop.com.