The Shift Assistant Pro

The Shift Assistant Pro retrofit for BMW Motorrad is an aftermarket upgrade that allows for clutchless, bidrectional gear changes on compatible models. Originally a factory option for certain bikes, the retrofit brings this feature to motorcycles that did not have it installed from the factory. 

Key features

• Bidirectional clutchless shifting: Allows for both clutchless upshifts and downshifts in almost all load and engine speed ranges, eliminating the need to operate the clutch or roll off the throttle.

• Reduced shift times: The system provides significantly faster gear changes, contributing to greater dynamics and a more engaging riding experience.

• Increased comfort: Frees up the rider's clutch hand, which is especially beneficial in stop-and-go traffic or for long-distance touring.

• Optimized shifting behavior: The system manages the precise timing of engine torque reduction for upshifts and throttle-blips for downshifts, resulting in smooth and precise gear changes.

• Simplified installation: Depending on the specific kit, it may be a "plug and play" solution for a qualified technician. 

Components of the retrofit kit

The retrofit kit typically consists of several key parts: 

• Shift linkage with sensor: This replaces the original linkage and includes a strain gauge sensor that detects the rider's intent to shift when they press on the gear lever.

• Adapter cable: Connects the new shift sensor to the motorcycle's electronics.

• ECU programming: The bike's Engine Control Unit (ECU) must be programmed to recognize and operate the new hardware. This often requires a special enablement code and must be performed by an authorized BMW Motorrad dealer or a specialist with the right diagnostic tools. 

Compatibility and installation

• Specific models: The retrofit is not available for all BMW Motorrad models. It is commonly offered for liquid-cooled bikes from certain years, such as the R 1200 GS (2014 and later) and the S 1000 series. Older models, like the 2013 liquid-cooled R 1200 GS, are often not compatible.

• Coding is required: The process is not a simple bolt-on installation. It requires an authorized dealer or a specialist to perform the necessary ECU programming (coding).

• Dealer vs. aftermarket kits: While an official BMW dealer can perform the retrofit, independent companies also offer kits with all the necessary hardware. Some of these aftermarket kits may even offer what they claim is "optimized" shifting functionality. 

How it works

The system's operation is intelligent and load-dependent:

• Upshifting: When the rider presses the gear lever to upshift, the sensor detects the movement and immediately sends a signal to the ECU. The ECU then briefly cuts ignition and fuel injection to unload the gearbox, allowing the gear to engage seamlessly without the rider closing the throttle or using the clutch.

• Downshifting: For downshifts, the system uses "blipping" or a double-declutching function. It detects the downshift request and briefly blips the throttle to match the engine speed to the transmission speed, allowing for a smooth and fast gear change. 

Riding with Shift Assistant Pro

• Clear shifts are necessary: The system requires a firm, positive actuation of the gear lever. A slow or half-hearted press can cause issues or result in the bike accidentally shifting into neutral.

• Throttle discipline: For the smoothest shifts, riders should maintain a steady throttle position during upshifts. For downshifts, the rider does not need to blip the throttle manually; the system handles it automatically.

• Performance varies: Some owners, particularly those with four-cylinder bikes like the S 1000 series, report very smooth shifts. Owners of Boxer engines, like the R series, may find the results vary, with some reporting a less "buttery" feel due to the bike's suspension and driveshaft angle. 

The procedure for retrofitting the Shift Assistant Pro on a BMW Motorrad motorcycle involves two main parts: the physical installation of the new hardware and the electronic coding of the bike's ECU. The complexity varies depending on the specific motorcycle model and whether you are using a dealer or a third-party kit. 

Step 1: Preparation and pre-installation

1. Verify compatibility: First, confirm that your specific motorcycle model and model year are compatible with the Shift Assistant Pro retrofit. Compatibility often depends on the type of Engine Control Unit (ECU) installed.

2. Purchase the kit: Obtain the necessary retrofit kit, which typically includes:

   1. A replacement shift linkage with an integrated strain gauge sensor.

   2. An adapter cable to connect the sensor to the bike's wiring harness.

   3. An enablement code (often purchased separately through a dealer).

3. Gather tools: Gather all necessary tools, including standard metric motorcycle tools, a torque wrench, and potentially bike-specific tools for removing bodywork or accessing the gear shifter. 

Step 2: Mechanical installation

1. Remove the stock shift linkage:

   1. Access the shift lever and linkage by removing any necessary bodywork or panels.

   2. Detach the stock shift linkage from both the gear lever and the gearbox arm. Pay attention to the orientation and placement of any spacers or washers.

2. Install the new shift linkage with sensor:

   1. Fit the new shift linkage, which contains the quickshifter sensor, in place of the old one.

   2. Make sure the orientation is correct to ensure the sensor functions properly.

   3. Torque all bolts to the manufacturer's specifications. Some bolts on the shifter may have left-hand threads.

3. Connect the wiring:

   1. Use the provided adapter cable to connect the new quickshifter sensor to the motorcycle's main wiring harness.

   2. The location of the connection point varies by model, but it is often found near the engine or transmission.

   3. Route and secure the new wiring away from heat sources and moving parts. 

Step 3: Electronic coding and activation

This step must be performed by a professional with the correct diagnostic equipment, such as an authorized BMW Motorrad dealer or a specialized tuning shop. 

1. Acquire the enablement code: The dealer will generate a Feature Enabling Code (FSC) specific to your bike's Vehicle Identification Number (VIN). This code tells the ECU that the new hardware is present and should be enabled.

2. Connect to the ECU: The technician will connect their diagnostic tool (e.g., ISTA, E-Sys) to the motorcycle's diagnostic port.

3. Perform the Vehicle Order (VO) change:

   1. The technician will add the Shift Assistant Pro option to your bike's vehicle order, which is the list of options stored in the ECU.

   2. The FSC code is used to authenticate and allow this change.

4. Code the ECUs: After the VO is updated, the affected ECUs are coded to activate the new software feature. This may involve a complete recoding of the ECUs to incorporate the new options.

5. Run adaptations/calibrations: Some installations may require running specific service functions, such as throttle position sensor recalibration, to ensure the new quickshifter operates smoothly. 

Step 4: Final checks

1. Test the system: Take the motorcycle for a test ride to confirm that both upshifts and downshifts work correctly without using the clutch.

2. Verify operation: Ensure that the bike is shifting smoothly under varying loads and RPMs, and that there are no error messages on the dash.