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The X1 Stealth is the all new lightweight mid drive conversion system. With up to 1500W of power output, a small form factor, and a more silent performance, this is the ideal system for ebike & emtb riders wanting a stealthy setup.
All the things you need to know about your CYC ebike X1 STEALTH mid drive motor including kit options, compatibility, battery choices, & services.
If you have any other questions or want recommendations, don’t hesitate to contact us.
Installation of X1 Stealth only takes around 1-2 hours. This short installation time allows you to easily convert from MTB to E-MTB.
Follow the link below for all documents needed for the X1 Stealth including the user manual, mobile app guide, & display manual.
The links below will redirect you to video installation guides for the X1 Stealth:
Video installation guide for press-fit BB92 version (coming soon)
The X1 Stealth kit support several bottom brackets, including the traditional BSA threaded bottom bracket, and press-fit bottom brackets.
The X1 Stealth BSA threaded options fit bottom brackets ranging from 68mm to 83mm with extra spacers included in your kit should you need it. The pressfit option includes the BB92 version. BSA threaded and press-fit bottom brackets are the most common among mountain bikes. Below is a guide to help choose the correct option for your CYC Motor kit and how you check which bottom bracket you have.
If you already know what bottom bracket you have, refer to the chart below. If not, continue reading after the chart for guidance.
What bottom bracket do I have?
There are two main types of bottom brackets
1. Traditional BSA threaded bottom brackets
These bottom brackets are assembled to the bike frame by threads. When these bottom brackets are removed from the bike frame, you can see that there are threads on both the bottom bracket, and the bike’s bottom bracket shell. The BSA threaded bottom brackets can be further separated into two types namely, the BSA threaded bottom bracket with external cups and the BSA threaded bottom bracket with a sealed cartridge.
a) BSA threaded bottom bracket with external cups:
This type of bottom bracket has two external cups one on each side of the bottom bracket. The external cups typically have bearings pressed inside the cup that face outward from the thread that is directly in contact with the bottom bracket.
The cups are typically threaded on to the bike by using a bottom bracket wrench as shown below.
b) BSA threaded bottom bracket with a sealed cartridge:
This type of bottom bracket has two parts to it. The first part is a spindle and a drive side cup assembled. The second part is a non-drive side cup alone. Both cups are threaded on the face in contact with the bikes bottom bracket.
This type of bottom bracket needs to be removed using a different bottom bracket tool.
The bottom bracket diameter can be measured according to the image below. Here are the typical measures of the BSA bottom bracket:
The typical widths of the BSA threaded BB are 68mm (road bikes), 73mm (mountain bikes), 83mm, 100mm and 120mm. The 68mm to 83mm BB option will fit all the diameters in between with additional spacers included in the kit.
2. Press-fit bottom brackets
These bottom brackets, on the other hand, are pressed into the bike frame. It stays there by means of strong friction between the bottom bracket cups and the bike’s bottom bracket. The easiest identification of the press-fit bottom bracket is that there are no threads inside the bike’s bottom bracket, or on the bottom bracket cup.
Usually there are no clear installation marks for press-fit bottom brackets, as these kinds of bottom brackets require the press-fit tools to install and remove them.
Currently, we support BB92 press-fit bottom brackets with a width of up to 92mm as well as BB107 and BB109 press-fit bottom brackets with a width up to 109mm. The bottom bracket diameter of the BB92, BB107 and BB109 is 41mm.
Based on the information above, you can determine whether you have a BSA threaded or press-fit bottom bracket and refer to the 1st chart for the right option in your kit.
CYCMotor supplies 2 various chainring options for the X1 Stealth as shown below and come standard with an aluminium chain guard. When choosing your chainring, keep your desired ground clearance in mind. It is also important to note that the options will not affect the speed or torque of the motor, only the pedal feeling of the rider when the motor is switched off. Click here for more information.
The sprocket on all options has a 104mm BCD which means that you can switch to any standard chain sprocket or even belt pulley for Gates carbon belt system.
11/53T Option
The 53T 219H sprocket has an outer diameter of 136mm. It comes with an inner 32T bike chainring by default which is included in the kit.
11/63T Option
The 63T 219H sprocket has an outer diameter of 160mm. It comes with an inner 38T bike chainring by default which is included in the kit.
PowerOutput
The X1 Stealth is paired with the ASI BAC855 controller. The maximum battery voltage that the ASI controllers can accept, is 72V (20s) nominal. The BAC855 has a battery current limit at 65A and can support up to 50A continuous current.
Below is the calculated expected power based on the nominal voltage and continuous current rating. Note that the motor’s peak power is 2500W.
With the BAC855, the expected power of the motor is:
1800W with 36V batteries
2200W with 44V batteries
2400W with 48V batteries
2500W with 52V batteries
2500W with 60V batteries
2500W with 67V batteries
2500W with 72V batteries
Top Speed
The voltage also affects the maximum speed that you can achieve. The motor Kv is 150, which means that the maximum RPM of the motor is equal to the motor Kv multiplied by the nominal voltage:
5400 RPM with 36V batteries
6600 RPM with 44V batteries
7200 RPM with 48V batteries
7800 RPM with 52V batteries
9000 RPM with 60V batteries
9400 RPM with 67V batteries
9400 RPM with 72V batteries
The top speed at the crank varies with the chainring options you choose. Read more about how the chainring options affect your cadence at the crank here.
To calculate the top speed you will achieve, please input your bike gear ratio and maximum RPM to the cadence in this link.
Batteries
The ASI BAC855 controller accepts batteries from 36-72V (nominal), which means that lithium-ion batteries of 10s to 20s all work well with the motor system. 72V (20s) batteries fully charged is around 84V.
We summarized the following range for a 65kg rider for your reference:
Normal ride style – Run in PAS mode at around 500W (e.g. trail riding) : 10Wh/km.
Aggressive ride style – Run in Throttle and PAS mode at more than 1000W : 20Wh/km.
Kindly read the article in this link to get a better idea of which battery suits your needs and how to get a clearer idea of your achievable range.
The motor and controller overall, has an efficiency of over 90%.
