There are 2 main types of electric bike motors – ones which fit into a wheel (the motor can be in the front or rear wheel) or ones where the motor is connected to the pedals of the bike. These are referred to as “hub-drive ebikes” or “mid-drive ebikes” respectively.
Which style suits you best will depend on your purpose, your budget and your rider confidence and/or skills.
Purpose – if you are considering an electric bike for recreation, commuting, trekking or just short trips to the shops, the type of electric bike may be important to you. A hub-drive electric bike is a great entry into riding with pedal assistance (the motor turns on when you pedal and the motor power turns off when you stop pedalling) and suits relatively easy recreational and commuting riding but is less suited to varied terrain, trekking or rougher path surfaces or for those riders who want a more natural and responsive feel. Understanding your purpose and the areas in which you wish to ride is an important starting point to appreciating which type will suit you best.
Budget – with electric bikes, you generally get what you pay for. Prices comprise a combination of motor performance, braking system, gearing type, battery capacity and design. Branding also plays an important part in the overall cost of an electric bike. Big brand names often command higher prices due to their prestige, but this may not always reflect performance.
Generally-speaking, a hub-drive will be less expensive than a mid-drive. Our hub drive bikes go up to around $2500. Design and engineering-wise, fitting a motor into a wheel requires the motor itself and the spokes to be laced into the wheel but the rim does not need to change necessarily and the frame of the bike does not need to be redesigned. For this reason, a hub-drive electric bike is often at least $1000 cheaper than a mid-drive and sometimes much more than that. If you are on a budget, a hub-drive is a great starting point.
Most folding electric bikes are hub-drive based and this helps keep these bikes in the lower-end of the budget range. Our hub-drive motors fitted to off-the-shelf electric bikes are generally either factory branded or Bafang sourced. Other suppliers fit a range of hub-drive motors such as Electra and NCM. Our conversion motors are either Bafang or torque-based Tong Shen brands. Both torque and voltage impact overall cost for conversions.
The brand also affects the budget of the electric bike and the brand of the motor is part of this equation: we stock both Bosch (German) and Bafang (Chinese) mid-drive motors fitted to our off-the-shelf electric bikes. Bafang motors have high-torque performance as standard (M400 80Nm, M420 80Nm) whereas Bosch offer a range of performance depending on budget and purpose. Active Line (45Nm) is their entry level motor and the performance increases with motor type (Active Line Plus (55Nm), Performance Line (65Nm), Performance Line CX (85Nm) and Cargo Line (85Nm)). Not all Bosch motors are the same and the higher the performance, the more expensive the motor. “Nm” stands for Newton Meters and is a measure of the torque or rotational force that the motor can produce. The higher the Nm the better the bike will be at hill climbing. Note that the battery capacity does not change the torque or power of the motor, the capacity affects the range or distance that you can go on the bike.
Rider confidence and/or skills – most hub-drive electric bikes operate using a sensor which detects whether the pedal cranks are turning. The cadence sensor does not measure the force or speed that you are pedalling, it just detects if the pedals are rotating. As an example, when riding on the flat, with the bike set to the maximum power assistance level (PAS level) you can pedal slowly and the bike will try and pull you along at 25kph, regardless if you pedal fast or slow. Note that all legal electric bikes are limited to 25kph with power assistance and the motor power stops when you stop pedalling. The bike can go faster than 25 kph (eg if you are going down hill ) but if you try and pedal faster than 25 kph you end up with a heavy mechanical bike as the power will turn off.
For some riders the disconnect between how hard and fast you are pedalling and the motor power can be disconcerting and riders who wish for a more natural experience may prefer the logical connection exhibited from a mid-drive whereby the more you push on the pedals, the more response the motor will provide, given the level of power assistance range selected.
In part, the suitability also links back to the purpose of the ride. If you are wanting to go on steeper hills, a rider on a mid-drive who is willing to put in effort will immediately gain that reward from the motor. Where terrain changes rapidly, such as on a rail trail when crossing creeks, the need to quickly change from downhill to uphill or trying to negotiate potholes or sandy, loose surfaces it is harder to manage and control on a hub-drive compared to a mid-drive. Mid-drive responsiveness helps on varied terrain whereas a hub-drive is easy on flatter and more consistent cycleways. It does come down to the confidence and skills of the rider and where they are riding.
Mid-drive electric motors are often considered better quality but that is not always the case. A hub-drive may be more appropriate if you have weakness in your lower limbs and are unable to use a lot of force to increase the pressure on the pedals. In these circumstances, a mid-drive may not be best for you.
In terms of gearing, with the hub drive bike the motor is directly connected to the wheel rim, a smaller wheel will provide a lower gear (better for going up hills). With a mid drive bike the motor power goes through the mechanical gearing of the bike which helps when going up hills because the power you put in and the motor power are both going through the bike gearing.
Another consideration when looking at the hub drives and mid drive bikes relates to changing of a trye. With a hub drive ebike the wheel with the motor in it cannot be quick release. The nuts holding the wheel on need to be done up very tight to ensure that the axle does not spin when the motor starts turning. This means that if you needed to change a tyre on the side of the road then you need spanners not just a standard bike tool kit. With a mid drive bike the wheel are “standard” bike wheel and in some cases can be quick release which require no tools to remove the wheel. This is something to consider if the bike will be used for trekking and other offroad riding where you may not have access to a full set of tools.
Typically for the same battery capacity and the same riding terrain a bike with a mid drive will go further than a hub drive bike because you cannot “cheat” or take it easy with a mid drive. You always have to put some effort in to get the motor to turn on. With a hub drive you can take it easy by using a higher power level and pedalling slowly, this will use more battery power.
Electric bike riders with a disability – If riding with a disability, electric bikes can be an ideal way to reduce the impact of your disability on the use of a bike. Electric pedal assistance can reduce the impact of fatigue, muscle weakness, endurance and temperature management. A hub-drive motor where the rider does not have to push too hard on the pedals is ideal for someone living with ankle, knee, hip weaknesses or restrictions. These bikes are often easier to offer balance support using adult stabiliser wheels or as a trike.
If you are wishing to improve your strength and use not lose your muscles, a more natural mid-drive may enable you to control the power usage more easily so you can participate in a wide range of riding scenarios so you are able to ride longer, further and more frequently. We can also modify electric bikes to accommodate different seating requirements, braking strengths, handlebar configurations and pedal needs to suit your disability and offer you the best option to get onto a bike in a sustainable and regular way. As NDIS Providers, we often provide quotes for riders to access either hub-drive and mid-drive electric bikes as part of their NDIS plan.