Answers to most frequently asked questions

Have any questions about how Rubbee X universal ebike conversion kit works? Check out the answers bellow.

All orders are shipped from our HQ in Lithuania, part of European Union. So no additional duties or import fees will be collected when Your order is delivered within European Union.
When the order is shipped outside European Union (for example: United Kingdom, United States of America, Switzerland) the import fees will be collected by Your local customs authority when importing the order to Your country.

Rubbee X is probably the easiest electric bicycle conversion kits to install. Attach the lock mechanism onto the seat tube of Your bicycle and insert Rubbee X into it. There’s also a small wireless cadence sensor that must be attached to Your pedal crank before the first ride. But don’t worry – no wires or magnets go to or from it, just two cable ties to secure it and You’re good to go ! Rubbee X is considered to be the best e bike conversion kit regarding ease of installation. Bicycle compatibility chart can be found HERE.

Installation and what’s in the box can be found here:

Short answer – You control it by pedaling.


Rubbee X is controlled by an easy to install PAS (Pedal Assist Sensor) or in simpler terms – wireless cadence sensor. The sensor is mounted on the bicycle pedal crank and it provides information about when and how fast the person is pedaling. By knowing these things and combining them with the speed of the entire bike, Rubbee can control the amount of power independently without any user interference. When You are pedaling – Rubbee provides power. You stop pedaling – Rubbee stops providing power and starts freewheeling . Rubbee becomes a natural extension of Your muscle power. When a hill is encountered and Your speed is decreasing but pedaling rate increases Rubbee enables a higher power output. High speed and slow pedaling will have an opposite effect – a lower assistance level will be provided. Rubbee X makes these calculations and power modulations multiple times a second.


The maximum assistance power level of the ebike conversion kit can be controlled via the main button. Just press is to cycle through different power modes. ECO / CRUISE / POWER modes are available depending on how many batteries are installed. ECO is available with 1 installed module, CRUISE with 2 modules and POWER mode becomes available when all 3 battery modules are installed. These modes can also be changed via the smartphone application.

Yes it does !


When pedals are turned backwards for half of a revolution, regenerative braking mode is enabled. Since Rubbee X is an ebike kit with battery, when a long downhill section is encountered the regenerative braking can recharge the batteries. Normal operation is automatically resumed once pedals are turned to move forward. When the batteries are fully charged, the regenerative braking mode will not be available until the batteries are discharged to the allowed limit.

Rubbee is a friction drive. It has a rotating drive roller at the back end of the system which directly touches the rear wheel of the bicycle and helps You move forward. Simple. It provides additional power directly to Your rear tire when You need it the most.

In most cases, it does not slip. There are 3 key reasons why.

  1. Electronic anti-slip control. If slipping is detected, the motor torque modulates similar to how ABS system works in a car.
  2. Active suppression system. Rubbee X is pushed to the tire not only by it’s weight, but also with a 200N pneumatic cylinder.
  3. Special roller. Both material, shape and surface texture of the roller is optimized for increasing grip in all weather conditions.

Base model Rubbee X comes with 1 battery module installed. If You want more range, speed and power, You can install more batteries, up to 3 modules in total. Additional batteries increase the torque and range of Rubbee X . With all 3 modules installed the POWER mode becomes available. This mode is only for off-road and private roads since it exceeds power and speed limits of EU regulations.

To install extra batteries 6 screws should be removed from the bottom of the device and new batteries inserted. After installing new battery modules, the whole device must be plugged in to do a complete recharge.

Rubbee X adds additional wear to the tire but nothing that should be worried about. We cast the rollers from a specially developed polyurethane compound mix which guarantees the best contact between the tire and the roller. This compound also allows us to reach phenomenal grip in wet conditions. We test roller materials for thousands of kilometers (literally!) on the same tire without drastic wear&tear. In any case it is generally recommended to change bicycle tires every 2000-3000 km so we recommend to follow this rule. Cool fact – our roller material is also used in high-end sports cars suspensions !

Yes, Rubbee X electric bike kit is street legal in EU and USA. It follows the EN15194 e-bike regulations and has a rated power of 250 W, top speed of 25 km/h and it requires a PAS sensor to operate. Rubbee does not require license or number plate on the bike to operate. Just hop on and You are ready to go !

Yes! You can change from one bike to another in just a matter of seconds. The only thing You will have to do is to install the Second Bike Kit on the other bike. It includes a sensor and the lock mechanism. One Rubbee X – two (or more) DIY ebikes !

Rubbee has quite an extensive history. We’ve been producing these devices since 2013 although the product itself changed drastically throughout the years. You can find the whole story over HERE.