If you’re buying an e-bike in Australia, one of the most critical choices you’ll make is your motor system. Choosing the right drive, mid-drive or hub motor, can affect performance, reliability, cost, and how your bike feels under load. In this article, we break down the real-world trade-offs, especially for heavy fat tyre e-bikes (25–35 kg), explain why hub motors often make more sense in that category, and profile the top motor manufacturers you’ll see in 2025. For broader context on components, standards, and pricing, see our guide, Everything You Need to Know Before Buying an E-Bike in Australia (2025)
Why the Motor Decision Matters
The motor you choose is not just a spec, it shapes your entire ride. It determines how the bike accelerates, tackles hills, and how much maintenance you’ll face down the line. Especially on fat tyre e-bikes, which already carry weight and extra rolling resistance, mismatching motor and drivetrain is a recipe for frustration. That’s why, when deciding between mid-drive and hub motors, you must look beyond marketing claims and ask: which system gives the best balance of torque, durability, and real-world usability for your type of riding?
How Mid-Drive Motors Work
A mid-drive motor mounts at the crank and delivers its torque through the chain and gears. Because it works in concert with your drivetrain, it can leverage gear ratios to deliver more force at lower speeds, which is especially useful on climbs. The power delivery feels natural, as you pedal harder, the motor responds proportionally when paired with a torque sensor. Mid-drive systems tend to be more efficient on varied terrain. Because they can keep the motor in an ideal rpm band by shifting gears, they handle changes in slope more gracefully. However, every time you push the lever, that torque passes through the chain, cassette, and derailleur. On heavier bikes, that means those parts must be stronger and will wear faster. Replacement chains and cassettes add up. Also, mid-drive systems are more complex to service, with internal gearing, sensors, and seals that require precise work. In short, mid-drives shine when you want maximum versatility and performance, but their complexity and stress on the drivetrain make them less ideal when your bike is already heavy.
How Hub Motors Work
Hub motors are integrated into the wheel itself, usually the rear wheel. They spin the wheel directly, bypassing the chain and gears entirely. A hub motor doesn’t stress your drivetrain because the power doesn’t travel through the chain, it delivers rotational force straight to the rim. That simplicity brings reliability: fewer moving parts involved in power transmission, fewer points of failure. Hub systems are easier to install, easier to inspect, and simpler to maintain. For fat tyre builds, this lends a practical durability advantage. Hub motors don’t get the benefit of gear leverage, so on steep climbs they may draw heavier current or heat more. But for a well-sized, torque-rated hub motor, those pitfalls can be mitigated with good design and cooling. Because the motor isn’t pushing through the chain, you avoid accelerated wear on drivetrain parts, a major plus for heavier bikes.
Why Fat Tyre E-Bikes Often Use Hub Drives
Fat tyre e-bikes face unique challenges: greater rolling resistance, heavier frames, and wider rubber that adds drag. A fat tyre bike weighing 25–35 kg places significant mechanical load on the drivetrain if you use a mid-drive system. The chain, cassette, and derailleur must handle constant high torque. Over time, maintenance costs mount, especially in Australia where servicing may be harder in remote areas. That’s why True North uses a hub drive system, the Bafang G062.500D model, in its fat tyre bikes. This system delivers the torque needed for hills and load without routing it through the chain. It retains drivetrain life and reduces mechanical stress. Because hub drive systems put pressure directly into the wheel, they avoid the “weak link” problem of overloaded drivetrains. This is a key reason fat tyre e-bikes often favour hub drive systems: they isolate motor stress to the motor itself and spare the rest of the bike from constant high torque. When you’re buying an e-bike, understanding this trade-off helps you see why a hub system can be a smarter, more durable choice.
Ride Feel, Efficiency & Real-World Performance
Mid-drive systems, especially those with torque sensors, offer a very smooth, intelligent ride. The assist matches your exertion, giving a seamless, intuitive feel. That level of finesse is hard to beat. Hub systems traditionally lag behind in nuance, with basic cadence sensors triggering preset assist levels regardless of how hard you pedal. The result can be an abrupt “kick” when assist engages. However, many modern hub motors now integrate torque sensing or advanced control ramps, bridging that gap. On hills or mixed-terrain routes, mid-drives often maintain efficiency by shifting the motor to an optimal rpm. That can preserve battery life. But on steady, flatter stretches, hub motors can be as efficient or even more so, because fewer mechanical conversions occur. In fat tyre use, with high basal loads, a robust hub motor may be more practical, its losses don’t scale with drivetrain inefficiency. Mid-drives generate noise in the gearing area and can heat up if pushed continuously, especially uphill. Hub motors can hum quietly, or be nearly silent at low loads, though they too can get warm under heavy loads. In good designs, effective cooling, sealing, and component quality keep temperature in check. For fat tyre bikes doing moderate speeds, both systems are well within safe ranges when well built.
Top Motor Manufacturers and What They Do Well
When you shop for an e-bike, certain names stand out. Below are top motor manufacturers you’ll commonly see (in hub, mid, or hybrid roles), and what each is known for.
- Bosch
Leader in refined mid-drive systems with smooth power delivery, tight integration, and a large dealer network. Common on premium commuter and trekking e-bikes with strong long-term support. - Shimano
Mid-drives that pair naturally with Shimano drivetrains for a predictable, bike-like feel. Reliable parts availability and service pathways make them a safe choice for everyday riders. - Brose
Very quiet operation and strong torque that many e-MTB riders prefer for its unobtrusive, natural assistance. Suits riders who value a hushed, high-quality feel on trails and mixed terrain. - Yamaha
Decades of motor expertise translate to broad, usable torque bands and durable systems. Often chosen for commuter and touring e-bikes where reliability and consistency matter. - Bafang
A wide range of hub and mid-drive units with strong global adoption and parts access. Popular on fat-tyre, cargo, and general consumer e-bikes thanks to solid torque, value, and serviceability.
You’ll also encounter other specialist names, but these five dominate the mainstream and help set expectations on support, integration, and performance.
Reliability, Servicing & Long-Term Costs
Choosing a reliable motor brand gives you peace of mind. Bafang’s strong global footprint means parts and overhauls are easier to access in Australia. But beyond brand, the system design matters: quality sealing, bearing selection, and modular components make a difference. Hub motors naturally require less drivetrain maintenance because they bypass it. Chains, cassettes, and derailleurs on hub-driven bikes often last longer. Mid-drives, by contrast, accelerate wear, especially in heavy e-bike configurations. In remote or regional areas, servicing mid-drive internals may require specialist tools or shipping, with potential delays and costs. Hub motor replacement or servicing can often be done at a local wheel workshop or by motor specialists with simpler procedures.
System Should You Pick Mid-Drive or Hub Motor?
If your riding is mostly flat or coastal paths, a hub motor will serve you reliably and simply. If you face daily hills or want the most natural ride feel, a mid-drive may feel better if your bike is light enough or the drivetrain is built robustly. For fat tyre e-bikes, the logic tilts strongly toward hub systems. The benefits to drivetrain longevity, lower maintenance, and consistent torque application make hub drives a practical and wise choice in this segment. That does not mean mid-drives have no place, on lighter bikes or for high-demand use they shine. But as soon as your bike pushes 25–35 kg with fat tyres and you ride real terrain, hub drive becomes the more sustainable choice.
Summary
Motor choice is central to how your e-bike will perform, feel, and age. Mid-drive systems offer refined assist and hill leverage, but stress the drivetrain and demand stronger parts and more maintenance. Hub motors keep things simpler, and for heavy fat tyre bikes, they reduce wear on the bike. The Bafang hub motor architecture is one of the most dependable crosses of torque and serviceability available today. Five motor brands, Bosch, Shimano, Brose, Yamaha, and Bafang, offer mature systems you can trust. If you’re in the market for an e-bike, understanding this trade-off helps you see why many fat tyre models favour hub drive systems. And once you’ve picked your motor, you’ll want to match it with the right battery, brakes, tyres, and control systems, topics covered in our central guide, Everything You Need to Know Before Buying an E-Bike in Australia (2025).
