Electric bikes (e-bikes) are becoming increasingly popular for transportation, recreation, and fitness. A key component that defines the e-bike experience is the motor system – whether it’s hub drive or mid drive. But what exactly is the difference between these two types of e-bike motors? And how do you determine which is better for your needs?
In this comprehensive guide, we’ll cover everything you need to know about hub drive vs mid drive e-bike motors, including:
- What is a hub drive motor?
- What is a mid drive motor?
- The pros and cons of each type of motor
- How to choose between hub drive vs mid drive
- Real world examples and applications
- FAQs on e-bike motors
Let’s start by clearly defining these two common electric bike motor systems.
Contents
What is a Hub Drive Motor?
A hub drive motor is located inside one of the wheels of the e-bike, either the front hub or rear hub. Essentially, the motor replaces the standard hub that the wheel spins around.
Diagram showing the location of a rear hub drive motor. Image via ElectricBike.com
Hub motors come in two main types:
1. Geared Hub Motors
These motors have an internal set of planetary gears that reduce the motor’s high RPMs down to a lower RPM more suited for the sizes of e-bike wheels. The gears provide more torque, which helps when accelerating from a stop and climbing hills.
Geared hub motors are generally quieter and smaller than direct drive motors. However, the internal gear system does have more potential points of failure.
Overall, geared hub motors strike a good balance between torque and efficiency in a compact package.
2. Direct Drive / Gearless Hub Motors
Direct drive (DD) hub motors have no gears and directly drive the wheel. This makes them simple and robust with few moving parts to break. DD hubs provide lots of torque for hill climbing ability at the cost of efficiency. So the range from a given battery will generally be less than a geared motor.
Gearless DD motors excel at high top speeds, making them well-suited for electric moped style e-bikes. And because they transmit all of the motor’s power directly to the wheel, you get the benefit of “free wheel” when coasting. This avoids potential drivetrain loss from internal gears.
DD motors also provide regenerative braking since they can generate some electricity when braking down hills. However, the amount of energy recuperated is fairly small in real world riding.
What is a Mid Drive Motor?
A mid drive motor is located in the middle of the bike frame, mounted in the bottom bracket area between the pedals. Instead of driving the wheel directly, mid drive motors provide power through the bicycle drivetrain – meaning the chain, gears, crankset and rear wheel.
Cutaway diagram showing mid drive motor location. Image: Dave/EBR
This allows mid drive systems to take full advantage of the bike’s gearing, applying power through whichever gear is selected. Want to climb a steep hill? Just downshift to an easy gear ratio for improved torque and lower cadence. Hitting higher speeds on flat ground? Upshift gears for a faster spin.
So in effect, mid drives turn your bike into an electric bicycle with a “virtual” gearbox covering a wide RPM range – all while protecting the motor from excessive strain.
Mid drives are also positioned centrally on the bike, helping centralize mass and improve overall handling relative to hub motors. And by driving the rear wheel via the chain, they maintain equal power distribution to both wheels for better traction.
Hub Drive vs Mid Drive Motors Compared
Now that you understand the basics of what distinguishes hub drives and mid drives, let’s compare them across some key performance factors:
Torque and Hill Climbing Ability
- Hub drives can put down decent torque thanks to internal gear reduction. But they lack the mechanical advantage of mid drives coupled to bicycle transmissions. Most mid drives deliver 70+ Nm of torque compared to around 40-60 Nm for geared hub motors.
- Winner: Mid drive motors have vastly more torque and hill climbing ability by utilizing bicycle gearing.
Efficiency and Range
- Mid drives tend to be more efficient overall, converting a higher percentage of battery power into usable mechanical power. This translates into longer range compared to a hub drive system with the same size battery.
- Hub motors waste more energy through internal losses, drag, and heat buildup. Lower efficiency limits their range.
- Winner: Greater drivetrain efficiency gives mid drives better range.
Top Speed
- Direct drive hub motors can reach higher top speeds by virtue of lacking gear reduction. High speeds up to 28 mph (45 km/h) or more are possible.
- Mid drives usually have speed limits around 20-28 mph (32-45 km/h) set by controllers to prevent damage from over-revving. Their top speed depends partially on motor kv rating and gearing.
- Winner: Hub motors for maximum speed. But mid drive speed is still sufficient for legal Class 3 e-bike classification.
Weight Distribution and Handling
- Hub motors place more mass on one wheel, which can adversely affect handling – especially heavier DD hubs. Large hub motors also add unsprung and rotating mass.
- Centrally locating the motor mass improves weight distribution for mid drives. This lends better handling and maneuverability overall.
- Winner: Mid drive motors help centralize mass for superior weight distribution and handling properties.
Price and Affordability
- Good quality hub motors start around $150-300 for mass market products from major suppliers. Complete wheel builds with hubs and rims add $200+ .
- Mid drives have far fewer budget options. Name brand systems often cost $800+ just for the bare motor. Some affordable Bafang mid drives start around $500 though.
- Winner: Hub motors win for lower price and barrier to entry. Pre-built hub motor wheels are convenient and economical.
Maintenance and Reliability
- Hub motors are generally sealed and maintenance free. At worst, worn hub motor bearings might need occasional greasing or replacement.
- Mid drives have more moving parts including precision planetary gears. This requires periodic inspection and replacement of wear items. Chains and sprockets also require lubrication.
- Winner: Hub motors edge out mid drives in terms of reduced maintenance requirements. But mid drives aren’t necessarily unreliable with proper care.
Motor Noise
- Hub systems emit mechanical noise from the motor magnets, gears, and moving parts. Noise increases with motor load and temperature.
- Mid drives mostly make noise through the drivetrain via the chain and gears. Shifting quality affects noise as well. Vibration and buzzing from the motor itself is less noticeable.
- Winner: Relative noise levels can vary greatly depending on system quality. But mid drives tend to run quieter overall in real world usage.
Regenerative Braking
- Direct drive hub motors provide regenerative braking from their simple design and fixed connection to the wheel. This charges the battery to a small extent when going downhill.
- Regen tends to be complicated and less effective with mid drives due to the disconnect through gearing. So most mid drive systems lack meaningful regenerative braking altogether.
- Winner: Hub motors offer the capability for regen braking, even if advantages are minor.
Real World Applications: When to Choose Hub Drive vs Mid Drive
With all those factors to weigh, how do you decide between hub drive vs mid drive for your electric bike? Here are some general guidelines and recommendations based on intended e-bike usage:
Mid Drive Motors: Ideal for Mountain Biking and Hills
Mid drives really shine for off-road trail riding where their ample torque, efficient power delivery, and balanced handling exceed the capability of hub motors. Shifting through gears to match terrain and cadence is a natural fit for MTB trails. And mid drive power coupled with quality bicycle components is a proven combination for tackling technical climbs.
Most pre-built electric mountain bikes make use of mid drive technology from respected brands like Bosch, Shimano, and Brose. Boutique mid drive systems from Bafang and TSDZ2 also work well for converting standard MTBs with just a bottom bracket swap.
Basically if riding authentic singletrack trails or steep forest service roads is the goal, choose a mid drive e-bike hands down. The power and handling benefits are perfectly suited for technical terrain. Riders wanting the most sporty, “natural” riding feel derived from shifting also prefer mid drives to augment their pedaling.
Hub Drive Motors: Great for Urban/Commuter Use
Nothing beats the simplicity and affordability of hub drive motors for basic urban transportation and commuting needs. The “all-in-one” design of hub motors is perfectly adequate for flat city riding and moderate hills. And with pre-built hub motor wheels starting under $500, converting an existing bike to electric is cheaper compared to mid drives.
Hub drives also accommodate recharging via regenerative braking during city riding. Plus the wider availability of high speed direct drive hubs caters well to faster paced cycling or urban moped duties.
Commuters also appreciate how hub systems keep moving parts sealed and away from the elements. You can ride care-free in wet conditions with minimal maintenance besides re-greasing bearings as needed. Overall, the grab ‘n go convenience and low maintenance of hub motors suits most urban e-bikes.
So if you mainly stick to paved paths, roads, bike lanes, and mellow terrain in an urban environment, we recommend looking at hub drive options first.
Examples: Hub Motors VS Mid Drives on Real E-bikes
To further demonstrate real world applications, let’s compare some actual production e-bikes using either hub motors or mid drive systems:
Rad Power Bikes RadWagon
RadWagon Electric Cargo Bike with Geared Rear Hub Motor. Image: Rad Power Bikes
- Motor Type: 750W Geared Rear Hub
- Application: Urban/cargo transportation
- Terrain: Roads and bike paths
- Notes: Rad Power Bikes outfits many of their models with dependable geared hub motors for affordable prices. The RadWagon cargo hauler demonstrates how hub motors suit street usage despite the heavy load – especially with the motor positioned at the rear.
Specialized Turbo Levo
2019 Specialized Turbo Levo Electric Mountain Bike with Custom Mid Drive Motor. Image: Specialized
- Motor Type: Custom Specialized SL 1.1 Mid Drive, 240W Nominal
- Application: Technical mountain biking/off-road
- Terrain: Dirt trails to bike parks
- Notes: Specialized collaborated with partner Brose to develop their bespoke mid drive system specifically for outstanding off-road usage. The Levo lineup dominated eMTB awards and epitomizes mid drive excellence for tackling tough terrain.
Hopefully these real world examples of production e-bikes demonstrate when hub motors or mid drives excel based on riding environment and demands.
E-Bike Motor FAQs
Here are answers to some frequently asked questions we receive about electric bicycle motors:
Are hub motors or mid drives more powerful?
- Hub and mid drives have similar peak wattage ratings typically between 250W-1000W. So on paper, power levels are comparable.
- But mid drives generate drastically more torque by utilizing gearing – often above 70 Nm vs 40 Nm for direct drive hubs. So mid drives feel noticeably more powerful especially for climbing.
Can you shift gears with a hub motor?
- Yes, hub motors allow normal shifting of your bike’s rear derailleur. Though gearing affects speed, not power or torque output like with mid drives.
Do mid drive motors break chains more often?
- Breaking chains is definitely a risk on lower quality mid drive bikes if you shift improperly under power. However, most major mid drive manufacturers have vastly improved software and intelligent shift detection to prevent issues. So chain breakage has become quite rare.
Which type of e-bike motor is quieter?
- Hub motors emit noise directly from internal magnets/rotors and gears. Mid drives are quieter from the motor itself with drivetrain noise depending on chain maintenance. Good mid drives paired with quiet gearing and belts can be extremely quiet.
Are hub motors or mid drives better for conversion kits?
- It depends! Hub kits offering pre-built wheels are an easier conversion requiring just battery and controls mounting. But mid drive kits allow using your existing bike’s gearing for better performance. Both have reasonable learning curves for DIY installation.
How much do e-bike motors cost?
- Hub Motors: Entry models start around $150-$300. Pre-built wheels with basic hubs, rims and spokes go for $400-$800 normally. Higher power DD hubs run $700+.
- Mid Motors: Quality mid drives usually run $800+ for just the bare motor. But affordable options from Bafang can be found around $500. Complete mid drive wheel builds are often $1200+.
Hopefully these common questions provide more insight so you can determine whether hub motors or mid drive systems better match your riding needs and budget.
The Verdict: Hub Drive vs Mid Drive Motors
So what’s the final verdict – which type of e-bike motor reigns supreme? The truth is that both hub drive and mid drive motors have merits depending on your priorities and riding style. E-bikes thrive because of this variety and customization.
For trail riding and hills, mid drives clearly dominate as the best electric bike motor option. They amplify rider input through shifting to expertly balance torque, efficiency, heat management and control. Nothing shreds singletrack better than mid drives paired with quality gearing and braking components.
Yet you can’t dismiss the simplicity and affordability of hub drive motors perfectly suited for casual urban mobility. Hubs keep commuting practical with reduced maintenance, regenerative braking capabilities, and availability of higher speed direct drive configurations.
We vote mid drive motors as the premier option for their performance advantages and broad compatibility with bicycles when implemented properly. Hub drives aren’t too far behind though considering their costs and suitable flatland handling.
Hopefully this guide has armed you with ample knowledge to decide whether hub motors or mid drives better fit your e-bike ambitions. Let us know if you have any other questions in the comments!
