Know exactly what to look for when you come to the shop
Congratulations, you have decided to upgrade to an e-bike! Now you are confronted with many choices and you are not too sure where to start. No problem - you are just one of those new riders trying to find what machine is best for you and your intended price point. While there is a lot of information out there, we think one of the best ways to start your search is by examining the motors and batteries. Those two components influence an e-bike’s performance, price, and weight, so finding the right drive unit and battery for your riding needs and budget is the best place to start.
All e-bike motors start with the same basic function: converting electrical energy into mechanical energy, and there are three primary motor designs.
Mid-drive motors position the motor between the cranks, where the bottom bracket would be.
High torque, efficiency and centred weight distribution make mid-drive motors popular on electric mountain bikes, and e-cargo bikes and higher quality hybrid bikes. However, mid-drive e-bikes often cost more than comparable hub-driven models because hub motors are cheaper to manufacture. But if you’re looking for something that efficiently climbs up hills, goes off-road or simply provides the most smooth, natural ride, go for a mid-drive electric bike.
An example of a mid motor bike
Hub motors are as they sound: within a bicycle’s front or rear hub. They come in two basic variants, direct-drive and geared. Typically 3 to 6 inches in diameter, the hub has spokes attached to its exterior and electromagnets lining its interior. When you apply power, the electromagnets spin the hub, causing the wheel to rotate. A direct drive hub motor has just one moving part and is therefore cheap to make and reliable.
They’re ideal for cruising at high speeds because they become more efficient the faster you go.
An example of a hub drive electric bike
Your wallet is going to feel the e-bike’s battery more than any component, so you’ll want to know how you’re spending your cash. Most e-bikes use lithium-ion batteries, the type you find in cordless drills and leaf blowers. They’re favoured for their high energy density and durability.
Battery capacity is measured in watt-hours (Wh), a unit of energy. Most e-bikes have batteries between 250 and 500 watt-hours.
An e-bike’s range will depend on the hilliness of your route, the bike’s weight, its tires’ rolling resistance, and other variables.
Before you buy, verify that the bike’s battery is lithium-ion (Li-ion). Some e-bikes use lithium polymer (LiPo) battery cells, which are popular in RC cars and drones because they’re even lighter and able to discharge more quickly than Li-ion cells. However, LiPo batteries typically come in laminate packaging rather than cylindrical cells, making them more prone to damage (read: fire hazard). Do not worry, Rothar only sells Li-ion battery equipped bikes.
Weight and Reliability
Beyond the motor and the battery, you'll also want to consider an e-bike’s weight and reliability. You don’t want an e-bike that’s too heavy to put on a car rack or constantly breaking down.
Weight: Electrifying a bike adds weight that will be more than compensated for while riding, which is another reason to consider the central weight distribution of the mid-drive motors. However, there’s no e-assist for hoisting the e-bike onto a tray rack or into the back of a minivan, so you’ll also want to consider how often you’ll have to pick the bike up. Consider if you’ll be bringing it up stairs or into public transport. If traveling with the bike is top of mind, be sure to choose an e-bike that has an easily removable battery to reduce significant weight. Many hitch racks are now being developed to accommodate the heavier e-bike with easier loading solutions.
Reliability: Just like acoustic bikes, electric bikes sometimes break down and require regular maintenance. The electric components (motor, battery) on an e-bike will not be as easy to replace as the mechanical components (cassettes, shifters), so make sure they come from a sustainable company that has a proven record of longevity. Before you buy, consider how you’d be able to service the bike—something not every bike shop will do. Brands like Bosch, Shimano or Mahle have an extensive global dealer network for in-person service, while others may send out a technician or ask you to send the bike back. Either way, be sure to know your options if something goes wrong.
Conclusion: Knowing what you want the bike to do will be the deciding factor - if you want something light that will give you a boost on hills, when the wind is blowing or that you have to bring to the first floor, a hub drive motor will be better. If you want to bring heavy loads, use the bike for deliveries or just want something powerful, we will advise you towards a mid motor. Our entire range can be found here, don't hesitate to contact us if you want more information.