Grin Kits

Want to purchase a conversion kit from Grin but not sure where to start? This page is intended as a solid primer on the various options and should help narrow things down to the kit most suited to your needs.
List of Grin Hub Motor Offerings

Basic Kit Choice

Our two most popular hub motor conversion systems are the geared eZee kits and the direct drive Crysatlyte H35 kits. Both of these offer great performance to meet 90% of user needs, are available both front and rear, and are stocked prelaced into rims from 20" up to 700c in size for immediate shipment. The geared eZee hub is lighter (~4kg, vs 7kg from the H35), and has better torque output and efficiency for climbing hills and pulling cargo, while the heavier Crystalyte H35 motor is more appropriate for high speed setups and is capable of regenerative braking;

Asides from these two, we also have a number of specialized kits for niche applications; folding bikes, high power offroad bikes, and mid-drive cargo bikes. The TDCM IGH kit is a high-end direct drive motor with a 5-speed internal gear hub all in one package, while the 9C+ and Bafang G01 kits offer budget conversions of great value. Here’s a summary breakdown of the current packages that we've put together at Grin, from smallest to largest. 


Crystalyte NSM

Example of an NSM Motor Conversion Kit

Quick Specs
Motor Weight 2.7 kg
Typ. Power 200-400 W
Motor Type Direct Drive
Wheel Sizes 16" (ISO349)
Front Only

 NSM Kit: The Crystalyte NSM is the smallest direct-drive hub motor on the market and is specifically tailored for          Brompton and Tikit folding bikes, with a narrow 75mm axle length to fit with no fork spreading. Available front only in 16”    ISO349 rims. 

 

Crystalyte SAW20

Quick Specs
Motor Weight 3.4 kg
Typ. Power 250-500 W
Motor Type Direct Drive
Wheel Sizes 16", 20"
Front Only

Example of SAW Hub Motor Kit

 SAW20 Kit: This hub is suitable for folding bikes with 75mm forks where the power output of NSM isn’t quite adequate.  It’s larger in diameter and heavier but maintains the narrow profile as the NSM. Comes laced 16” and 20” rims, allowing it  to work with most 20” Dahon/TERN bikes along with the Tikit and Brompton.

 

Bafang G01 Mini Geared

Quick Specs
Motor Weight 2.7 kg
Typ. Power 250-500 W
Motor Type Geared
Wheel Sizes Unlaced
Front Only

Example of Outrider Hub Motor Kit

Bafang G01 Geared Kit:  This is a smallish geared motor is well suited for people who want a more minimal level of assistance than the eZee hub. Being a geared kit, it freewheels when not in use, and being lightweight it has little effect on the characteristics of a bike. Front unlaced, fast rpm wind for small wheel builds, low rpm for regular builds

 

eZee

Quick Specs
Motor Weight 3.8 kg
Typ. Power 500-1000 W
Motor Type Geared
Wheel Sizes 20",26",700c
Front and Rear

Example of eZee Hub Motor Kit

eZee Kit:  The eZee system is our popular high performance geared motor setup, and has about twice the power and torque capability of the Outrider motor (500-1000 watts), making it better suited for steeper climbs and cargo hauling. The ~4kg motor is available in both front and rear options, and comes prelaced in 20”, 26”, and 700c wheels with a Schwalbe Marathon Plus tire too

 

Stokemonkey

Quick Specs
Motor Weight 5.1 kg
Typ. Power 400-800 W
Motor Type Mid-Drive
Compatilbity Cargo Bikes

Example of Stokemonkey Kit

Stokemonkey Kit: This is a simple mid-drive drive setup specific to cargo bikes which drives through a tandem crankset, allowing the motor to take advantage of the variable bicycle gearing. It mounts on most longtail bikes (Yuba Mundo, Edgerunner, Big Dummy) and bakfiets (Cetma, Long John), and has better efficiency than a hub motor when carrying heavy loads up steep grades.   

 

Cycle Stoker

Quick Specs
Motor Weight 5.1 kg
Typ. Power 400-800 W
Motor Type Mid-Drive
Compatilbity Edgerunner
Yuba Mundo

Example of Cycle Stoker System

Cycle Stoker Kit: This variant of the Stokemonkey system drives on the right via a 2-speed Patterson crankset, allowing for much higher pedal assist speeds than most other mid-drives. Unlike the classic Stokemonkey, it has pedal torque sensing capability and freewheels so that the motor doesn’t force the cranks to turn. The motor mounting system is particular for each bik frame, and at present there are options for the Xtracycle Edgerunner and Yuba Mundo cargo bikes. 

 

TDCM IGH

Quick Specs
Hub Weight 6.5 kg
Typ. Power 600-1200 W
Motor Type Direct Drive
Wheel Sizes Unlaced
Rear Only

Example of TDCM IGH Kit

TDCM Internal Gear Hub Kit:The TDCM IGH hub features a direct drive motor with an internal 5 speed Sturmey Archer hub for the human transmission, so you get in one clean package a 5 speed gear hub and a powerful motor. It's a great option for people wanting to do conversions on single speed bikes without a derailleur. This motor is manufactured in Taiwan and the quality and build standards are excellent when compared to most chinese motors. It comes pre-filled with Statorade for optimum heat dissipation.

 

Nine Continent 27XX

Quick Specs
Motor Weight 6.2 kg
Typ. Power 600-1200 W
Motor Type Direct Drive
Wheel Sizes Unlaced
Front/Rear

Example of 9C Rear Kit

Nine Continent + Kit:Nine Continent is a company that normally makes hub motors in high volume at low prices for the domestic China market. However, we've been able to work with them to produce a 9C+ series of direct drive motors that uses 0.35mm laminations for reduced drag, and is sealed for Statorade with an injection hole under the disk screw. The mechanical design of these motors as bicycle hubs is so so (disk alignment and caliper clearance are pretty bad, some spoke flange wobble is common) but their performance as efficient direct drive motors is excellent. We have them available unlaced in front and rear in 3 different winding speeds.

 

Crystalyte H 35 Series

Quick Specs
Motor Weight 7.5 kg
Typ. Power 600-1200 W
Motor Type Direct Drive
Wheel Sizes 20", 24", 26"
and Unlaced
Front and Rear

Example of Crystalyte H35 Kit

Crystalyte H Kit: The H35 series from Crystalyte is a motor is our standard direct drive hub motor, and the 35mm wide stator and magnets gives it about 30-50% more torque than most inexpensive hubs with 24-27mm magnets, while better design allows it to fit disk brakes both on the front and rear.  The motors have some heft and are well suited for fast and powerful ebike setups. Being direct drive they are quiet and capable of regenerative braking, but they also have somewhat higher drag resistance than less powerful direct drive motors. 

 

Crystalyte The Crown

Quick Specs
Motor Weight 9.2 kg
Typ. Power 1000-3000 W
Motor Type Direct Drive
Wheel Sizes 24", 26", Unlaced
Rear Only

Example of Crystalyte Crown Kit

Crystalyte Crown: The largest motor that we have on hand is The Crown series from Crystalyte, which is suitable for setups that want to ride more like an electric moped. The Crown TC40 motors are huge, and are so wide that they only fit a single speed freewheel on the rear.  There is also a narrower TC30 option that does fit 7 speeds in a 135mm dropout at the expense of less power. They are commonly used on hefty downhill bikes with full suspension, and run plenty of power with 48V to 72V batteries.  

 

Battery Choice: Speed and Range

Batteries are not included with any of the conversion kits so that you have the freedom to pick any pack of your choosing to achieve the desired speed and range requirements for your ride, whether from us or from a 3rd party battery vendor. Most of the kits are optimized for use with 36 and 48V batteries, although there can be reasons to use voltages higher or lower than this. 

For each motor series we usually have several windings available, which determines the maximum RPM that the motor will spin at a given battery voltage. The combination of the motor winding, your battery voltage, and your wheel diameter determines the maximum speed at which the wheel can still provide assist. This information is summarized at the bottom of each kit page like so, and updates in realtime when you change the selection. 

Example of Conversion Kit Basic Performance Preview

Please understand that the unloaded speed is NOT the speed at which you will travel, that is the speed that the motor will spin when it is lifted off the ground, you'll need to use our Hub Motor Simulator to get the exact behavior for your setup with differrent rider weights, hill grades etc:

Most prelaced hubs we have configured to do at least 32kph under load when run with a 36V battery pack, and ~40kph with a 48V battery. While the top speed of a conversion kit is determined in part by the battery voltage, the range that you will get on a single charge is a function of your battery's capacity, measured in amp-hours or watt-hours. If you have twice the battery capacity, you will have twice the range. However, if you travel faster or go up steeper hills, then your mileage for the same capacity battery will go down. Please see our battery pack info page for numeric examples of the expected range for the batteries that we offer. A safe assumption for a typical ebike is that you'll consume 10 wh/km, while a fast or powerful ebike will be more like 15-20 wh/km.

Control, Basic Throttle vs. Advanced PAS

All of the hub motor kits are available in two package types a) with a V3 Cycle Analyst and options of torque sensors or PAS control for those who want an advanced customizable ebike setup, or b) with just a throttle input, and either a V2 CA or LED console for the display, for those wanting a more basic throttle controlled system.

BASIC Kit:

If you opt for the Basic kit, then you are getting a simple control package where your throttle plugs in directly to the motor controller in order to regulate motor power. It’s manual control all the way, and the display (whether eZee LED meter or a V2 Cycle Analyst) is mostly along for the ride, showing you what is going on but not actually being in the driver’s seat.

This approach is recommended for anyone who is not looking for too many bells and whistles and just wants a conversion kit with a throttle accelerator. If you don’t want anything technical on the handlebars, then get the eZee LED meter to show your approximate battery level and set 5 different power levels.  If you’d like an actual display of battery voltage, amp-hours consumed, speed, distance, wh/km etc. then choose the V2 Cycle Analyst display.   

ADVANCED Kit:

A key element of every Advanced kit option is the V3 Cycle Analyst. This device acts as its own control center, taking any range of sensor signals (throttle, ebrakes, torque sensor, PAS sensor, temperature sensor) and then processing that to regulate the bike power how you want it.  

The Advanced option is essential if you want to create an ebike system that uses pedalec control, using a PAS or Torque sensor to automatically power the motor whenever you are pedaling.  It is also essential if you are doing a powerful system where you want to tame the bike’s throttle response, or automatically scale back power before the motor overheats.  The V3 Cycle Analyst provides way more customization and configuration options than you would find in most other ebike systems. That can be either a blessing or a curse depending on how you roll with technology! 

Controller Size

With some kits, we have provided a few different controller options as well. In general, a higher current motor controller will give the kit more power and acceleration off the line, but will have no effect on the top speed and will be more stressful on the battery pack. All kits except for the eZee kit can be run either sensored or sensorless. We include hall sensors in all the motors and ship the kits assuming they will be run sensored, which provides best performance when starting from a standstill. The setups can at any time be run sensorless by simply unplugging the motor hall cable. The eZee kit however comes with a different eZee controller and can only be run sensored.

Regenerative Braking

All the direct drive motor kits are capable of proportional regenerative braking with the included Grinfineon controllers. For this, you will also need either an ebrake switch, or a V3 Cycle Analyst for throttle regen. Regenerative braking is not possible in geared kits like the eZee/Outrider, or with mid-drive systems.

Legal Compliance

Any setup that includes a Cycle Analyst can be configured via the Cycle Analyst to have custom speed limits and power limits in order to be compliant with the various electric bicycle regulations in different parts of the world. So it is perfectly possible to run a fast and powerful offroad ebike, and then have it throttled to say 250 watts and 24kph to meet the european electric bike limits when riding on road. But it is up to you as the person building and assembling the ebike to configure this. As supplied there is no intrinsic limiting enabled.