CYC Motor X1 Pro Gen.4 – The Most Powerful Electric Bike Motor for the 2025 Season. Part II.

CYC Motor X1 Pro Gen.4 is a complete electric drive system for a bicycle, intended for converting a traditional bike into an e-bike. It is the most powerful motor available on the market. Here’s everything you need to know about it. This is part two of the article – all about the X1 Pro Gen.4.

Part I

read here

Part II

Table of Contents

• Bottom Bracket Types
• Displays
• Crank Arm Lengths
• Throttle Types
• X12 Controller
• Bluetooth Speed Sensor
• Chain Tensioner and Spring Issue
• Optional Components

Complete Electric Bike Drive: Bottom Bracket Type as a Key Factor for Correct Kit Selection

The basic compatibility aspect between the motor and your bike is matching the bottom bracket. This is because the motor module is mounted to the bottom bracket shell in the frame. Therefore, all parts of the complete electric bike drive must be compatible with the frame. X1 Pro electric motors are compatible with BSA (threaded) bottom brackets ranging from 68 mm to 120 mm, as well as press-fit bottom brackets. How did CYC Motor engineers handle compatibility with so many bottom bracket types? They made some simplifications but most importantly cleverly designed the way the drive mounts inside the frame’s bottom bracket shell. They designed their drives to have their own sleeves (with bearings) that are inserted into the shell and tightened. This way, the shell doesn’t even need to be threaded. Shell width is handled by various lengths of left clamping sleeves and different lengths of ISIS axles, while compatibility with press-fit shells (which have larger diameters than threaded BSA) is achieved with a simple adapter.

Below is a diagram to check your own bottom bracket and select the correct X1 Pro drive version.

Available options:

• Bikes with BSA threaded bottom brackets (68 mm to 83 mm wide) are supported by the standard X1 Pro kit, which is 83 mm wide, and any gap is filled with spacers. The axle in this case is 180 mm long. If your bike has a 68 mm shell, you’ll add 15 mm of spacers when installing the motor. The kit includes spacers in 3 mm, 5 mm, and 7 mm thicknesses. If your frame is 73 mm wide, you’ll use 10 mm of spacers, and for 83 mm, of course, no spacers. Thin adjustment shims are also included to handle non-standard widths (e.g., 72.5 mm). The only downside is an increased Q-factor for shells narrower than 83 mm. Q-factor in this setup is 200 mm.

• Press-fit BB92 bottom brackets require a longer axle (200 mm), with a resulting Q-factor of 220 mm. Spacers are also needed, as the 200 mm axle is for 100 mm shells, and BB92 is usually 92 mm. A longer left clamping sleeve than the standard version is also required.

• 100 mm wide bottom brackets (fat bikes) – same as above, but no spacers needed.

• 120 mm wide bottom brackets (also fat bikes) – require a 220 mm axle (Q-factor becomes 240 mm) and an even longer left clamping element.

Different clamp widths are required depending on bottom bracket width

For all non-standard configurations (other than 68-83 mm), motor mounting plates differ because they must accommodate wider shells, as shown in the comparison photos below. The same applies to motor clamps around the frame. One simplified conclusion – before purchasing, determine your bike’s bottom bracket type and order the correct X1 Pro kit, because changing to a set compatible with a different bottom bracket is not as simple as with the CYC Motor Photon drive we discussed here. That said, CYC Motor has prepared conversion kits between different types of bottom brackets – ready-made sets with all necessary parts to switch if needed.

Sample kit required to switch between bottom brackets (in this case from BSA 68-83 mm to BB92)

Complete Electric Bike Drive: Choosing a Display

As with every CYC Motor electric motor in current generations, you have two display options – the smaller SW102 and the larger DS103. The small one is monochrome and integrated with control buttons. It’s usually mounted under the left thumb on the handlebar. The large display is in color and mounts in the center of the handlebar, with control buttons placed within thumb reach. Until recently, only the DS103 was available because it was the only one supporting up to 72 V. However, now the SW102 also works not only up to 52 V but now up to 72 V as well. It’s also worth mentioning – as we are often asked – that the voltage values refer to nominal voltage. A fully charged 72 V battery (20s) can reach 84 V. Displays take this into account, so there’s no risk of damage from high voltage. User manuals are available here:

• SW102
• DS103

Complete Electric Bike Drive: Choosing Crank Arm Length

Each CYC Motor electric kit comes with two crank arm length options: 165 mm or 175 mm. Shorter cranks are used for smaller bikes, shorter riders, or when you want more ground clearance while pedaling, especially with low bottom brackets. The crank arms are made of durable 7075-T6 aluminum. They are mounted using ISIS splines and feature a 5-degree offset.

Complete Electric Bike Drive: Choosing a Throttle Type

CYC Motor electric motors come standard with a throttle, meaning you can ride with motor assistance without pedaling. The most common and standard option is the thumb throttle, typically mounted on the right side under the thumb. Other options include:

• Half-twist throttle (similar to grip-shift gear mechanisms)
• Full-twist throttle (like those used on motorcycles)

Throttle operation is smooth and effective. Besides continuous riding (not generally recommended), it’s useful in many situations. Example uses:

1. Boosting power during steep or technical climbs when you need instant power to avoid losing balance
2. Riding through deep ruts or off-camber terrain where pedaling might hit the ground
3. Crossing streams or shallow rivers – riding with feet lifted to avoid getting wet 🙂

You can choose not to install the throttle and disable it in the app, but it comes as standard equipment, not an optional add-on.

Complete Electric Bike Drive: Controller

The controller in the X1 Pro Gen.4 kit is the CYC X12. It’s roughly twice the size of the previous X6 controller used in Gen.3 and in the X1 Stealth Gen.3 kit. It’s developed by CYC Motor on the open-source VESC platform. This means the CYC Motor controller’s source code is available at: github.com/CYC-MOTOR.

Key specs:

• Voltage range: 36 V – 72 V (supports 10s to 20s battery packs)
• Peak phase current: 180 A
• Peak battery current: 100 A

The controller is rated IP66, meaning it’s fully sealed and resistant to strong water jets – but not submersible.

The X1 Pro motor can be mounted in the standard way – under the downtube of the front triangle. But if your frame allows, it can also be mounted inside the triangle. In that case, the controller must be placed elsewhere (it won’t fit in the motor cage). For this setup, optional extension cables are available to position the controller farther from the motor.

It connects via Bluetooth to mobile devices.

Speed Sensor with Bluetooth Module

In the new generations of CYC Motor mid-drive systems, the speed sensor also acts as a Bluetooth module, making it essential for connecting with the CYC Ride Control app, available for both Android and iOS. Due to the number of features, a full description of the app is beyond the scope of this article.

Chain Tensioner and Spring

The chain tensioner was a source of issues at one point, as the manufacturer modified its design to make installation easier. A smaller spring was introduced, but it proved to be problematic – the springs would break. The manufacturer has now returned to the previous, more robust solution, using a dual-spring system.

Complete Electric Bike Drive: Optional Components

– Brake Sensors

Brake sensors are used to instantly cut motor power when the brake lever is pulled. By default, the motor stops working in two situations: when pedaling stops or when the throttle is released. In the first case, there may be a slight delay due to the design of the cadence sensor. That said, brake sensors are not required. They are useful when braking and pedaling at the same time – a rare scenario, usually occurring when slowing down (e.g., approaching an intersection) while needing to turn the cranks to change gears. Using brake sensors requires a different main cable from the motor – one with four branches instead of the standard two. The split cable connects to: (1) the display, (2) the throttle, and (3) & (4) both brake sensors.

– Lighting

The lighting system connects to the power cable and includes its own switch. Two lighting modes are available – high and low beam – and two color options: yellow and white. The setup consists of two powerful, independently mounted headlights on the handlebar.

Our video showcasing CYC Motor lighting capabilities is below:

Summary

Leaving out internal technical construction details (bearings, gear mechanisms, clutches, etc.), we’ve now covered everything about the most powerful electric bike motor on the market – the CYC Motor X1 Pro Generation 4. This was the second part of the article. The X1 Pro Gen.4 is designed for building high-performance electric bikes. If your needs are more modest, lighter, smaller, and more affordable motors like the X1 Stealth Gen.3 or the Photon are excellent alternatives.

Part I

read here