Overview

What is Interkewler?

Interkewler is a Lab 71 performance upgrade designed for the 2026 Cannondale Moterra Carbon and Carbon LT. It actively moves air through the downtube cavity surrounding the Bosch battery and drive system. The system consists of a high-efficiency blower fan, ducted housing, filter, retaining hardware, and associated wiring that integrates with the bike's electrical system.

Why was it developed?

Modern high-performance eMTBs generate significant heat during operation, particularly during long climbs, high-power riding, and hot-weather use. Testing performed during development demonstrated that battery and drive system temperatures can rise rapidly, even when a bicycle is stationary in direct sunlight. Internal studies found that a black carbon frame in direct sunlight can reach 108°F (42°C) inside the downtube in as little as nine minutes.

Interkewler was developed to help:

• Reduce the likelihood of temperature-related system derating providing a performance advantage over other bikes.
• Reduce heat buildup within the downtube.
• Improve thermal stability of the battery and drive unit.
• Improve usability in hot climates and high-load riding situations.

How does it work?

The blower fan draws ambient air into the downtube through a filtered intake. This air is then forced down the downtube, around the battery and exists the frame over the motor. This removes a significant amount of heat from the battery and motor, extending time to derating under extreme conditions.

Installation

Components required but not provided with kit

1. Replacement for System Controller located in top tube
   • Interkewler uses the frame hole where the stock System Controller (BRC3100) is located.
   • You will need to replace the system controller with a handlebar mounted controller, such as the LED Remote (BRC3600) or Purion 200 (BRC3800).
2. Bosch cables as required. You may need longer or additional cables to connect the new controller.

Tools Required

• T7 driver (included in kit)
• Appropriate M4 hex driver
• Standard tools for battery rail removal

Step 1 – Remove Existing Components

1. Power off the bicycle.
2. Remove the battery.
3. Remove the battery rail as required to gain access for installation. See owner’s manual supplement for details.
4. Remove the existing top-tube system controller if present and replace it with a compatible handlebar mounted controller.

Step 2 – Install Fan Assembly

1. Insert the fan assembly into the downtube through the battery door opening. 

2. Align the fan duct with the hole in the top tube.

3. Install the retaining ring, ensuring that the retaining ring notch is oriented toward the front of the bicycle.

   

4. Fasten the retaining ring using the supplied thread-forming screws, T7 driver.
   • WARNING! Do not overtighten the retaining ring screws, as the mounting features can be damaged.

Step 3 – Install Intake Filter and Grill

1. Install the filter element into the grill assembly if not already installed.

2. Engage the front tab of the grill into the retaining ring notch.

   

3. Secure the rear of the grill using the supplied M4 fastener.
4. Confirm the grill is fully seated and secure.

Step 4 – Route Wiring

1. Route the fan wiring above the battery rail, following existing cable paths.
2. Ensure wiring is protected from pinch points and moving components.
3. Connect the fan harness to the Bosch tail-light output connector, red socket.

4. Verify all connectors are fully seated before reinstalling the battery.

Step 5 – Reassemble and Verify Operation

1. Reinstall the battery rail.
2. Reinstall the battery.
3. Power on the bicycle.
4. Turn on the lights. Long press +

• If you cannot turn on the light port power, it may not be enabled in the Bosch firmware. You will need to use the Bosch service software to enable light operation.

5. Verify fan operation.
6. Confirm there are no warning messages in the Bosch system.
7. Perform a short ride test and listen for unusual noises or vibration.

Maintenance

Filter Cleaning

The intake filter should be inspected regularly and cleaned whenever significant dust or debris accumulation is visible.

FAQ

What is derating?

Derating is when the Bosch systems reduces power output to control motor and battery temperatures. This typically occurs during long climbs with sustained peak power output in high environmental temperatures, like an enduro climbing stage on a hot summer day.

Does the fan run all the time?

The fan will run anytime the lights are turned on via the Bosch HMI. There is no thermostat or other controller to automatically turn the fan on and off.

When should I turn the fan on?

Don’t wait until the system is overheating to turn the fan on. The earlier you start cooling the system, the longer you will delay derating. Even if the bike is parked while you are taking a break, the fan can continue to cool the system and prevent heat buildup from sun exposure.

Will the fan drain the battery?

The fan consumes 5w of power under normal operation. So, if you used the fan continuously on a 2 hour ride it would consume 10Whr of power or about 1% of an 800Whr battery.

Can I wash the bike with the kit installed?

Yes. Standard bicycle washing procedures can be used. But avoid spraying water into the fan inlet and cover if possible.

Does the kit improve motor power?

The Active Cooling Kit does not increase motor power but extends the amount of time you can use peak power. Its purpose is to help manage thermal conditions and reduce the likelihood of temperature-related performance reduction. Bosch drive systems begin power management strategies when internal temperatures become elevated, Interkewler slows the system heating and provides additional time until derating.

Will the kit prevent all overheating events?

No. Environmental conditions, riding style, vehicle load, battery state, and ambient temperature all influence system temperatures. The Active Cooling Kit is intended to improve thermal performance but cannot eliminate all temperature-related operating limits.

Will the Interkewler cause my system to break or otherwise damage the system components?

No.  The Bosch system will protect itself from damage in all the same ways, as intended.  There is no bypassing of safety features involved with the Active Cooling Kit.

What should I do if the fan is not operating?

1. Verify the bike powers on normally.
2. Confirm the fan connector is fully seated.
3. Inspect the wiring for damage or pinch points.
4. Check that the Bosch light output is enabled when required by the installation configuration.