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

CYC Motor X1 Pro Gen.4 is the most powerful electric bike motor, both in the Hong Kong manufacturer’s lineup and globally, available on the world market in 2024/2025. Here’s everything you need to know about it. Part I.

Part II

read here

Part I

Table of Contents

• Introduction
• X1 Pro Gen.4 Specifications
• Explanation of Parameters
• Who Is the X1 Pro Gen.4 For?
• Construction and Available Options
• Understanding Drive Sprocket Options

Introduction

There is probably no other mid-drive conversion motor on the planet currently that can boast greater power. The X1 Pro, now in its fourth generation and developed from the very beginning by CYC Motor Ltd., has a nominal power of 5,000 W (5 kW) and peak power of 6,000 W. There are also known cases of users “overclocking” the motor up to 8 kW and beyond. However, this is, of course, not allowed (warranty void).

This article covers the features of the most powerful electric motor for e-bike conversions, its parameters and construction, and—very importantly—the options in which it can be purchased to best suit your bike and personal riding preferences. A comprehensive article (exhausting not only the topic but also the author and likely some readers), from which you’ll learn nearly everything you ever wanted to know—but were afraid to ask.

Specifications of the Most Powerful Electric Bike Motor from CYC Motor Ltd.

The most powerful e-bike motors: left version with pressfit BB92 bottom bracket and 63T/38T gear set, right with BSA 68–83 and 53T/32T chainrings

Key specification highlights:

• Nominal power: 5,000 W (peak 6,000 W)
• Maximum torque at the crank: 280 Nm
• Maximum crank RPM (cadence): 300 RPM
• Top speed: >100 km/h
• Controller: CYC X12 (max current 180 A)
• Voltage range: 36 V – 72 V (battery packs 10s to 20s)
• Motor module weight with controller and chainring: 5.9 kg
• Total kit weight: 7 kg

What Do These Parameters Mean?

1. First, compared to factory e-bikes available in stores (which are legally limited to 250 W), the X1 Pro Gen.4 delivers 20 times more power. This has several implications, discussed further below.
2. Second, a bike built with this motor—especially when utilizing its full performance—has extremely high torque, which requires skilled handling (rear wheel traction loss, front wheel lift, etc.).
3. Third, such a bike can reach extremely high speeds, which also needs separate discussion.
4. Fourth, reaching full performance requires a properly matched battery, ideally with a nominal voltage of 72 V and high current capacity—which also means large and heavy.

Who Is This Motor For?

Given the facts above, it’s clear that the CYC Motor X1 Pro Gen.4, as the most powerful electric motor you can install on a bicycle, is not a toy and not for every rider (due to the riding skills required), and certainly not for every bike. It can technically be installed on nearly any frame with a standard bottom bracket, but due to the power, torque, and speed, the bike itself must be robust—built with strong components including the frame, suspension, wheels, and brakes.

Why was such a powerful motor created and who is it for? Two main groups of users choose this kind of setup:

1. Riders who want to use it off-road and enjoy the freedom of riding a powerful two-wheeled vehicle that, when used with a throttle (no pedaling), behaves more like an enduro motorcycle (depending on factors like suspension travel, tire size, etc.).
2. Users who like to have a “power reserve.” That means the ability to tap into high performance occasionally while mostly riding in a calm, everyday manner similar to standard e-MTBs. In such cases, the motor may never reach full power due to smaller battery setups. Many users choose this motor due to their body weight or mountainous terrain, using about 50% of its capabilities—around 2,500 W with occasional “boosts” when needed. This also helps extend the motor’s lifespan.

You can choose a motor cover in red aluminum instead of transparent—looks sporty!

V-MAX – How Fast?

How to calculate the theoretical top speed of a bike with this motor? First of all, top speed can only be achieved using the throttle, because the crank RPM (cadence) exceeds human pedaling capabilities. A high human cadence is about 100 RPM, while the X1 Pro reaches up to 300 RPM. For this example, let’s assume a 29-inch wheel with a 2.3″ tire, which has a circumference of about 230 cm (2.3 m). Using the largest chainring available—42T—and the smallest rear cog (11T, although 10T exists), we get a gear ratio of 3.81x. At 300 RPM, the speed formula becomes: 2.3 x 3.81 x 300 x 60 = ~160 km/h. Of course, this is purely theoretical, as real-world resistance will limit the actual top speed.

X1 Pro Gen.4 Kit Construction and Available Options

Now that we know who would want the most powerful e-bike motor and why, let’s discuss the construction of the kit and available options.

Understanding Drive Sprocket Sizes

The distinctive design of the X1 Pro (and its smaller sibling, the X1 Stealth) features a chain drive system from motor to chainring using an external chain. Components include: an 11T sprocket on the motor shaft, a thick gold chain (similar to motorcycle timing chains) transmitting power to a two-chainring assembly. The first receives power from the motor, the second is a typical bike chainring (narrow-wide), mounted with 4 bolts in the BCD104 standard. This transmission reduces crank RPM and increases torque at the crank.

The CYC Motor sprocket set consists of a steel BCD104 bike chainring, aluminum motor sprocket, aluminum cover, bolts, and spacers.

Here’s the first configuration choice: CYC offers 3 sprocket combinations, and changing the bike chainring also requires changing the motor sprocket to maintain optimal torque and cadence. Although you *can* swap only the bike chainring, it is not recommended. Available combos:

• 53T/32T – common in modern MTB setups (1×10, 1×11, 1×12)
• 63T/38T
• 72T/40T

How to Assemble the Sprocket Set and Mount It on the Freewheel Arm

Assembly varies based on bottom bracket type:

• BSA 68–83: two 6 mm aluminum spacers. Order: chainring cover + 6 mm spacer + motor sprocket + freewheel arm + 6 mm spacer + bike chainring
• BB92 pressfit: one 11 mm aluminum spacer and one ~2 mm steel washer. Order: chainring cover + steel washer + freewheel arm + motor sprocket + 11 mm spacer + bike chainring

Differences lie in spacers and motor sprocket mounting position (above or below the freewheel depending on bottom bracket type).

When choosing your chainring combo, consider:

• For mountain riding, prioritize high cadence (lower gears), lower speeds, and higher torque – choose 53T/32T
• For flat terrain and higher speeds with harder gears – choose 63T/38T
• For maximum torque and some speed gain – choose 72T/40T

While on the topic of chainrings, note the excellent build quality of CYC Motor components. CYC mid-drive kits aren’t cheap—but it’s clear why.

Also check if larger chainrings (especially 38T and 40T) will fit your bike without clashing with the frame or rear triangle. Use templates from the manufacturer’s website – here. Keep in mind these templates show the chainring *cover*, which is slightly larger than the chainring itself. Here are actual chainring diameters:

• 32T = 135 mm
• 38T = 160 mm
• 40T = 170 mm

Changing the chainring combo also changes the gold chain length:

• 53T = 40 links
• 63T = 43 links
• 72T = 46 links

Note: the X1 Stealth uses different chain lengths due to smaller dimensions and doesn’t support 72T/40T. In total, CYC offers 5 chain lengths.

Thick, gold chain transmitting power from motor to cranks

Part II

read here