Mid Drive eBike Kits
Mid-Drive Electric Bike Conversion Kits
There are a lot of advantages to installing a mid-drive electric bike conversion kit on your bicycle. Unfortunately, there is also a lot of marketing nonsense that is put out to glamorize the potential of ebike mid-drive motors.
We look into why mid-drive electric bike conversion kits are so popular, despite their relatively high price tag to other e-bike conversion kits.
This article dispels the myths and highlights the advantages of fitting a mid-drive electric conversion kit to your bike.
To highlight the advantages of mid-drive electric conversion kits, we compare mid-drive motors to hub motors to explain the difference.
What is a Mid-Drive eBike Kit?
The term mid-drive electric bike conversion kit refers to electric bicycle motors which fit in the middle of the bike. Most mid-drive electric motor kits mount the engine between the pedals. Mid-drive electric bike conversion kits are also referred to as mid mount ebike conversion kits.
Mid-drive engines can be located anywhere in the center of the bicycle between the front and rear wheels and, in more sophisticated eBikes, they can be discreetly integrated or hidden in the bicycle frame itself. Most mid-drive motors sit in the lower section of the bicycle frame between the pedal cranks and send power to the rear wheel through the bicycle chain.
By contrast, more popular, electric hub motors are positioned in either the front, or rear, wheel of the bicycle. Hub motors are integrated into the bicycle wheel itself. Where mid-drive motors require a chain to drive the rear wheel, hub motors power the bike directly through the wheel itself.
What is the Advantage of a Mid-Drive eBike Kit?
Mounting the electric motor in the middle of the bike provides several advantages, the most important of these is weight distribution.
Mid-drive motors do not clutter the rear axle of the bicycle allowing regular bicycle gear clusters to be fitted. A wide range of gears is important for many bicycle sports, especially mountain biking.
There is a further benefit of mid-drive electric motors where laws prevent the use of throttle controlled e-bikes. The pedal crank is often integrated into the mid-drive electric motor. Integrating the motor and pedals gives the manufacturer the opportunity to use pedal pressure sensors.
Mid-drive motors are often integrated with the pedal crank. Pressure sensors can be added to measure how hard the rider is pedaling. Motor management software can use information from pedal force sensors to intelligently help the rider. Motorized e-bikes then feel like regular bicycles that simply require less effort to ride.
Mid Drive vs Hub Motors
- Where electric hub motors are good for commuting and use or tarmac roads, mid-drive motors offer a better balanced bike which is important for xtreme sports. Mid-drive motors allow improved suspension and reduced strain on the spokes of the drive wheel.
- Sensors on hub motors can only provide information about the pedal speed. Mid-drive motors can provide detail of the pedal force that the rider is exerting. The advantage here is that management software can micro-adjust the power of the motor creating synergy between rider and machine.
- Rear wheel electric hub motors take up a lot of space around the rear axle. Gear clusters have to be narrower and often limit the rider to between 3 and 5 gears.
- Hub motors become less efficient as they approach their designed top speed. Gear selection on mid-drive motors keeps the motor closer to its most efficient speed. There is, therefore, a small efficiency in battery usage which can help extend travel distance.
- Front wheel hub motors lose traction off road as there is little weight over the drive wheel. Rock hopping becomes impossible as front end weight damps the bike’s agility. A front end hub motor provides no assistance when the weight is on the rear wheel.
- Rear wheel hub motors bog in mud and slide out on slippery corners. Poor weight distribution affects the way the bike lands after jumps making them more difficult to control. Extra weight at the back can make the bike awkward, and slower to respond to rider input.
- Extra weight of hub motors hamper the ability of the suspension to absorb bumps. If the tire has less time in contact with the ground this equates to less traction for the rider.
Mid Drive Motors Allow Manual Gear Selection
As mid-drive electric motors transmit power through the bicycle chain, the rider can manually select the gearing at the rear wheel. Gear selection allows the rider to intelligently select the best gear for the terrain.
Independent gear selection allows the rider greater control of the torque delivered to the road as they control both throttle and gears.
A big advantage of mid-drive motors is that they allow large, multi gear clusters to be fitted to the rear wheel. As mid-mount motors do not clutter the rear wheel in any way. This allows ebikes to provide the same range of gears that would be available on a regular bicycle. Electric mountain bikes with mid-mount motors can often offer 12 speed cassettes.
Being able to select the correct gear on a mid-drive motor will keep the motor closer to its best performance curve. Although the improvement is small, greater gear selection should help extend travel distance of the battery.
Mid-drive electric motors are not hampered by limited space at the rear axle and have no restrictions on the cassette that can be installed.
eBike Mid Drive Kits Have Better Weight Distribution
The second advantage of mid-drive motor e-bikes is their weight distribution. It is important for many bicycle sports (e-mountain biking for example) that the bike is balanced. Weight evenly spread between front and rear wheels provide more rider control and improved shock absorption.
Evenly distributing the extra weight of battery and engine between the bicycle wheels makes a huge difference in how the bike handles and performs.
Electric bikes with mid-mount motors behave like mountain bikes. The extra weight can make the eMTBs less nimble, but the power advantage offsets the drawback of additional weight.