Discover why E-bike Dual Front Motors can pull and how to fix torque steer. Get expert tips on troubleshooting, adjusting, and riding for a safer, more stable ride.
Have you ever hit the throttle on a dual motor e-bike and felt the handlebars lurch unexpectedly to one side? That sudden, jarring pull is known as torque steer, and it is a common issue with E-bike Dual Front Motors.
While it can be a surprising feeling, it is a problem rooted in simple physics and a common sign that one of the motors is working harder than the other. The good news is that this issue is almost always fixable, and this guide will walk a rider through exactly why it happens and what can be done about it.
The Physics of E-bike Dual Motors
The first step to fixing a problem is understanding it. When a manufacturer designs a dual motor e-bike, they are creating a true all-wheel-drive system with one motor in the front wheel and another in the rear.
The front motor provides a "pulling" sensation, while the rear motor provides a "pushing" sensation. This combination is designed to give the rider superior traction and stability, especially on hills or loose terrain.
The core of the issue, and the fundamental reason for torque steer, lies in the relationship between torque, traction, and weight distribution. In simple terms, torque is the rotational force that makes the wheels spin.
In a properly functioning dual motor setup, both motors are supposed to produce the same amount of rotational force to propel the bike forward evenly.
However, the weight of a standard bike is naturally biased toward the rear wheel, where the rider sits. This means the front wheel has less weight pushing down on it, resulting in less traction.
When a front hub motor applies torque, it tries to spin its axle backwards against the fork's dropouts while also trying to spin the wheel forward.
If a front motor gets more power than the other, or if one wheel loses traction, that unequal force causes the bike to steer in the direction of the more powerful or gripping wheel.
This imbalance creates the sensation of torque steer. The rider must actively compensate for it to maintain a straight line.
The situation becomes even more challenging with a dual front motor setup, a configuration that puts motors on both front wheels. This design significantly magnifies the steering instability and safety risks of a single front motor.
Instead of a balanced push-pull system, the rider is working against the physical challenge of applying a pulling force to two wheels with the least amount of static weight on them. This problem is further compounded when the rider accelerates.
The physics of acceleration causes the rider's weight to shift toward the rear, which further reduces traction on the front wheels and creates a vicious cycle that makes the problem worse right when the rider needs power the most.
Common Causes of Torque Steer
The feeling of torque steer can come from a number of different issues, from simple wiring problems to more complex component mismatches. The following is a breakdown of the most common culprits.
Mismatched Motors or Controllers
Not all motors are created equal, and this is a key consideration. Even if two motors have the same listed wattage, differences in their internal "windings" or build quality can cause them to deliver different amounts of torque and speed for the same electrical input. This is a fundamental, permanent flaw that cannot be fixed without replacing parts.
Similarly, if a bike uses separate controllers for each motor and they are not configured identically, one will always be more powerful than the other, causing a constant pull to one side. This issue is most often seen in DIY builds or budget e-bikes that use mismatched or low-quality parts.
The Problem with a Reverse Wire
A very specific and technical cause of torque steer relates to the way a motor may be wired. Some controllers and motors are equipped with a special "reverse wire" that allows the motor to spin backward.
In certain setups, to keep the brake calipers and cabling on the inside edge of the wheel, one of the motors is mounted "backwards" and the reverse wire is used to make it spin forward.
The challenge is that many controllers limit the power in reverse, which means the motor wired in this way will always have less torque than the other one, leading to a constant pull to one side.
Bad Connections or Damaged Components
An e-bike's brain is its controller, and it relies on precise signals from the motor's "hall sensors" to know how and when to apply power.
A loose, corroded, or broken wire can cause the system to lose synchronization, leading to erratic power delivery and sudden, jerky steering.
This is a particularly insidious problem because it can feel like a "ghost" in the system, happening at random and with no obvious cause.
A faulty hall sensor, which provides the motor with its position information, can also lead to inconsistent power output and cause a noticeable pull.
Battery and Voltage Sag
The battery's health and ability to deliver a steady voltage under load is crucial. If a battery is old, low on charge, or has a faulty cell, it can experience "voltage sag," where its voltage drops sharply when the rider accelerates heavily.
When this happens, the Battery Management System (BMS) may cut power to protect the pack, which can feel like a sudden shutdown or loss of power.
In a dual motor setup, this could affect one controller or motor more than another, creating a temporary but dangerous imbalance. The issue is exacerbated in cold weather, as lower temperatures increase a battery's internal resistance, leading to more pronounced voltage sag.
Simple and Immediate Solutions
Before a rider gets out their tools or starts swapping parts, there are some easy things they can do right away to fix or reduce the feeling of torque steer.
The Power of a Pre Ride Check
A simple, 30-second check can save a rider a lot of headaches. Walk around the bike and physically inspect all the cables.
Make sure the motor cables are seated firmly in their connectors and that there is no visible damage to the wires.
A small amount of corrosion or a slightly loose connection can cause a big problem, especially after a rough or wet ride.
Restarting the bike can also sometimes temporarily fix intermittent cut-outs.
Adjusting Your Riding Style
Since torque steer is ultimately a problem of traction and power delivery, a rider can actively influence it with how they ride.
Lean Forward
When applying power, especially on a hill or when starting from a stop, consciously shift body weight forward. This increases the load on the front wheel, giving it more traction and helping to prevent spin-outs.
Start with the Rear Motor
Many dual motor bikes allow a rider to activate each motor independently. A great technique is to start with only the rear motor to get momentum, then engage the front motor once the bike is already moving. This helps a rider avoid the sudden "jolt" and makes acceleration much smoother.
Use the Throttle Gently
Abrupt, full-throttle use can make the front wheels lose traction instantly, especially when starting from a standstill. A light touch and gradual acceleration are the best allies for maintaining stability.
Getting Your Tire Pressure Right
This is the easiest and most underrated fix. Underinflated tires increase rolling resistance and can negatively affect handling.
Overinflated tires reduce grip, which is a major problem on a dual front motor bike where traction is already an issue.
A rider should always check their tire's sidewall for the manufacturer's recommended PSI range and adjust it based on the terrain.
It is a good practice to use a lower pressure for better grip on loose surfaces like gravel or snow, and a higher pressure for efficiency on smooth pavement.
Advanced Troubleshooting and Hardware Fixes
When the simple stuff does not work, it is time to dig a little deeper. This is where a rider will need to do some more technical diagnosis and potentially install new components.
Programming Your Controller
Many e-bikes allow a rider to adjust how the power is delivered through the handlebar display or a programming cable.
A rider can often adjust settings such as the "zero start vs. non-zero start" mode, the level of pedal assist (PAS grades), and the overall strength of the motor when it kicks in.
By adjusting these settings, a rider can smooth out the power curve and make the bike less "jerky," which can significantly reduce torque steer.
It is highly recommended to save the stock factory settings before making any changes as a backup.
Torque Arms
Torque arms are a critical safety component for any front hub motor, especially a powerful one.
Without one, the immense rotational force from the motor can twist the axle inside the fork's dropouts.
This can lead to a catastrophic failure, causing the wheel to come off and sending the rider "over the bars".
A torque arm braces the axle, sending all the power into the wheel's rotation.
By preventing axle slippage, it also indirectly improves handling and stability.
| Benefit | Why It Matters |
| Prevents Axle Spin-Out | The motor's twisting force can shear off the delicate aluminum of a bike's dropouts. A torque arm braces the axle and prevents this catastrophic failure. |
| Protects Your Frame | By absorbing the stress, the torque arm prevents cracks and damage to the bike's most expensive component, extending its lifespan. |
| Enhances Performance | A stable axle ensures all of the motor's power is transferred into forward motion, leading to smoother acceleration and more predictable handling. |
| Increases Safety | A sudden loss of the front wheel is a major safety risk. A torque arm is an affordable, must-have investment to prevent a serious crash. |
Verifying Motor and Controller Health
If a rider is still having problems, they may have a deeper hardware issue. If the bike has a fully configurable controller, a rider can sometimes run diagnostics.
Otherwise, the best way to troubleshoot is to get the wheels off the ground and manually test them.
Spin each motor with the throttle and listen for any strange noises or uneven speeds.
If one motor is spinning slower than the other, or if it feels "choppy," a rider might have a bad hall sensor, a wiring issue, or a fundamental difference in the motor's windings.
Best Practices for Riding and Maintaining Dual Motor E-bikes
Once the torque steer issue is diagnosed and fixed, the best way to keep it from coming back is to adopt smart habits.
Riding Smart
Smooth Throttle Control: A rider should practice a light, gradual touch on the throttle. Abrupt, full-power acceleration, especially from a standstill, should be avoided.
No Throttling in Turns: This is a big one. A rider should never apply throttle mid-turn, as it can cause the front wheel to lose traction and "wash out". Instead, it is better to rely on momentum and apply power only when straightened out.
Know Your Terrain: It is important to be aware that loose surfaces like gravel, sand, or snow will cause the front wheels to lose traction more easily. A rider should adjust their riding style and power settings accordingly.
Maintaining Your Motors
While dual motors are known for their durability and for reducing the workload on a single motor , they still need care.
Regular Cleaning: Dirt, salt, and grime can corrode connectors and damage sensitive components. A gentle wipe-down after every ride, especially in wet or snowy conditions, will extend the life of a bike. High-pressure washers should be avoided as they can force water into sensitive areas.
Check Spoke Tension: Hub motors put a lot of strain on the spokes. A rider should get their spoke tension checked by a professional every 6-12 months. Loose spokes can lead to a wobbly wheel, which affects handling and can lead to more broken spokes.
Conclusion
Torque steer on a dual front motor e-bike can be frustrating, but it is not a mystery. It is a solvable problem that comes down to a power imbalance between the motors.
By starting with a simple pre-ride check and adjusting a rider’s riding style, the problem can often be fixed on the spot.
If that does not work, a deeper dive into controller settings or the addition of a safety component like a torque arm can get a rider back on the road.
By understanding the forces at play and adopting smart maintenance habits, a rider will not only fix the problem but also become a more confident and knowledgeable rider.
FAQs
What is a dual motor e-bike?
A dual motor e-bike has a motor in both the front and rear wheels, creating an all-wheel-drive system for more power and traction.
Do dual motor e-bikes have better traction?
Yes, dual motors provide better traction by distributing power to both wheels, which is great for hills or slippery terrain.
Is a torque arm really necessary?
Absolutely. A torque arm is a critical safety component that prevents the motor axle from spinning out, which can damage your fork or cause a dangerous crash.
How does tire pressure affect my ride?
Proper tire pressure enhances grip, reduces rolling resistance, and improves handling, all of which help to minimize torque steer.
Can I turn off one motor on my bike?
Many dual motor e-bikes allow you to switch between single and dual motor modes to save battery or get more stable handling.
