Compuboost sells premium Electric Bikes, or Ebikes. But sometimes a cheaper alternative is desirable. For example, one may like to try an electric bike conversion first, before committing a large sum for an advanced high powered electric bike.
We carry a universal bike conversion kit that fits cruisers, mountain bikes, fat tire bikes, small wheels and large bikes, even tandems. You can buy this as a kit, or let us convert your bike for you. We use this universal electric bike conversion kit to convert street bikes, road bikes, cruiser bikes, fat tire bikes, mountain bikes, 20″ tire bikes, 26″ street, mountain and road bikes, and even 27″ or 700C racing bikes and 29″ mountain bikes. We can even do tandem bikes.
All about electric bike conversions
Electric bike conversion means adding a motor to a bicycle, and then powering it with a battery via some sort of control, like a throttle or pedal assist.
There are several types of bike conversions. There is hub motor conversion, mid motor (crank) conversion, rear wheel conversion, front wheel conversion. Each has its advantages and disadvantages.
Front Hub motor Electric Bike conversion.
The front wheel is replaced with a hub motor. Either a direct drive electric motor, or a geared electric motor. The direct drive electric motor is commonly called a “pancake” motor, and it is relatively large and heavy. However, it provides large DC torque, and is simple to install and reliable.
Geared electric hub motor have a smaller circumference, and looks less like an electric bike. They are generally sturdy, but they do have a set of gears for motor speed reduction so they may be less reliable because of the extra moving parts.
Doing a front hub motor conversion is generally very easy. The front wheel is replaced with the motorized wheel. A pouch or bag to hold the batteries and controller is attached to the frame or to a rear carrier. A throttle is added to the handlebar and the conversion is done.
Front Hub Motor conversion can apply to all bikes, from cruisers, street, road, even mountain bikes, tandems and tricycles. For front suspension forks, the power cable to the motor needs to be long enough from breaking at maximum suspension travel.
Advantages of Front Hub Motor Electric Bike Conversion
Advantages of front hub motor conversion is simplicity, low cost, better distribution of weight (motor in front, battery in middle or rear), wide convertibility of nearly all bikes.
Disadvantages of Front Hub Motor Electric Bike Conversion
The front wheel must be replaced. The same braking system must be retained.
A major disadvantage of front hub motor conversion is adverse handling (front wheel is relatively heavy). The ride is different too, because torque is applied to front wheel in pulling bike, versus normal torque applied to rear wheel, pushing bike. Riding a front drive bike is a different experience, and things like leaning into a turn and dodging obstacles needs to be relearned.
Tire replacement is similar to no conversion.
Mid Motor (crank) Electric Bike conversion
A motor is attached the frame, and then using gears or chain, it drives the crank. Because it drives the crank, mid motors can take advantage of any gearing available (like a common derailleur setup) to drive the rear wheel.
Mid motor electric bikes, because they need frame modification, are common to custom bikes, especially European models, where the law limits the maximum motor power to 250 Watts.
Advantages of Mid Motor Electric Bike Conversion
Advantages of mid motor conversion is that smaller motors can be used, because of the amplification of the power or torque through gearing (derailleur or internal hub). The handling is not changed from a normal bike, nor are tire changing any different.
Because mid motors are common in Europe (and Japan) because of the smaller motor, and the peculiar requirement that they must be pedal assist (power applied only when pedaling), most mid motor are pedal assist, rather than throttle.
Disadvantages of Mid Motor Electric Bike Conversion
Disadvantages of mid motor (crank) conversion is complexity of attaching the motor and driving the crank. Usually the crank has to be replaced. A freewheel needs to be added to the crank (so that either the motor or the rider) can drive the crank independently. Mid motor conversion has a less “torquey” feel because the wheels are not driven directly, but through a chain or gears. Pedal assist is the normal method to control mid motor drives. Wear and tear on the drive train and chain is also much greater because the motor can apply much more sustained stress than any human can on the chain, crank and rear sprockets.
Mid motor conversions are generally limited to common bike frames with standard 68mm and 70mm (standard 26′, 27″, 29″ wheel size and frames) or 100 and 110 bottom brackets (fat bike). Many custom bike frames use mid motor, because the mounting brackets and modifications can be designed in.
Thus Mid motor conversion tend to be expensive, low in power, pedal assist and no throttle.
Rear Hub Motor Electric Bike Conversion
This conversion is similar to the front hub motor conversion, but instead the rear wheel is exchanged out. The hub motor conversion usually has the same gear cluster as the exchanged wheel, to keep changes in the derailleur and other rear components to a minimum.
Advantages of Rear Hub Motor Electric Bike Conversion
Torque is applied to rear wheel, so it feels most natural. It is not as easy to install as a front hub motor, but generally easier than a mid motor crank conversion.
Disadvantages of Rear Hub Motor Electric Bike Conversion
The rear wheel must be replaced.
The rear of the electric bike is generally very heavy. If the battery is attached to a rear rack, it will make rear of bike even heavier. In general it is difficult to replace the tube or change a tire for a rear hub motor conversion because the rear wheel has to be removed.
It is generally suited only for road bikes or cruiser bikes, not mountain bikes because of the rear suspension is not designed for such a heavy wheel.
Direct Drive Rear Wheel Electric Bike Conversion
A motor is attached to the rear stays. Then the rear wheel of the electric bike is driven via a chain or pulley. The motor is mounted on the rear stays, so it can be mounted on any triangular frame chain stays, regardless of other criteria, like size of wheel or type of bike. Hence direct drive is suiteable for road, mountain, fat tire, 20″, 24″, 26″, 27″ 29″ 700mm, even tandem bicycles.
Advantages of Direct Drive Rear Wheel Electric bike Conversion
The torque is applied directly to the rear wheel, so it feels most natural. The system can be very low cost, because external motors are less complex and cheaper than hub motors. It is also easier to service, since all motor parts are easy to access, unlike hub or crank motors.
Because the rear wheel is driven, the same conversion kit (universal) can be applied to any bike, large or small, cruiser, mountain, fat bike, 20″, 24″, 26″, 27″, 700C, 29″ wheels.
Disadvantages of Direct Drive Rear Wheel Electric Bike Conversion
It shares the weight concerns of Rear Hub motor drives, where there is a lot of weight over the rear wheel. It has a drive chain, so like the regular bike chain, it needs to be cleaned and lubed as well.
Compuboost Electric Bike Conversions:
Standard Electric Bike conversion
We generally do Front Wheel 25% or Direct Drive Rear Wheel drive 70% conversions. The balance is normal Mid-Motor crank conversions. We do this to keep the cost low, because for costlier conversions, it makes more sense to just get a full on custom Electric bike, which we carry.
Typically it costs about $600 for a standard Direct Drive Rear Wheel conversion (250W motor with a 8-10AH battery) usually good enough for 1-2 hrs run time (translates typically to 10-30 miles of travel. Larger batteries, and larger motors will cost more, and more difficult conversions like mid-motor crank, fat tire, tandem bike, tricycle, will cost more.
Fat Tire Electric Bike Conversion
We do fat tire electric bike conversion. Fat tire bikes are heavy because of the size of the wheels and tires, and the corresponding frame and fork needed to support that weight.
But riding a fat tire is no fun, unless the terrain is level or going downhill (but what about the ride back uphill?), so electrifying the bike is a must.
We offer a direct drive rear wheel conversion (36V motor, 450W, 12A
H Battery) for $950 complete, including installation. A fully converted new Fat Tire electric bike is available for $1450.
Tandem Electric Bike Conversion
Tandem Electric bikes can be converted so that riding uphill is more pleasurable. We offer both a front wheel as will as a direct drive rear wheel conversion. We also can offer independent dual drive, where both a front wheel hub drive (controlled by the front rider), and a direct drive rear motor (controlled by the rear rider) The cost for a direct drive rear wheel conversion (36V Motor, 450W, 12AH Battery) is $950 complete (single wheel), including installation, or $1600 (dual motors, batteries) including installation.
Allow about a week for the conversion.
Cargo Bike Electric Conversion and Tricycles
We also can convert cargo bikes and tricycles. We will generally advice front or rear drive based on the actual bicycle frame and projected usage.
Electric Bike Service
We service what we sell, as well as things we don’t sell.
We are a full service electric bike repair store, with the capability of rebuilding electric bikes from the ground up, rebuilding battery packs, servicing all brands of electric bikes, and doing many routine bike services like replacing tires, chains, brake pads, tune ups.