Electric bike conversion kits: the pros and cons

Electric bike conversion kits: the pros and cons

So you’ve got a bike already, are looking to save some cash, or want to tackle a hands on project? You may be thinking about eBike conversion.

Electric bikes in Australia are booming in popularity, and with good reason. They open up an ease of riding that isn’t otherwise available. But is conversion itself an easy undertaking? Let’s take a look at some generalised pros and cons, and then dive into the specifics.

Pros:
- If your bike is a good candidate for conversion, you’ll open up a whole new riding experience.
- If you’re attached to your bike, then converting it could bring it new life.
- If you have a lot of mechanical know-how, then conversions can be a great DIY project.

Cons:
- Not all bikes are good candidates for conversion. This is expanded upon below.
- So-called ‘universal’ conversion kits aren’t universal, with compatibility problems often arising in ways that aren’t initially obvious. See below for more.
- Many bike shops won’t work on a bike that has been converted with an electrical kit the mechanics are unfamiliar with or cannot get parts for. This could leave you in the dark when seeking help if something goes wrong.
- Some kits do not come speed capped at 25km/h. If their motor is rated at 200W or above and they are not capped, the bike will only be legal on private roads.
- Conversion projects often end up no cheaper than a ready-made eBike.

What kind of bike is best suited to electric conversion?

At Glow Worm, we look for three features on a bicycle when considering it for conversion:

1. Disc brakes – Ideally hydraulic ones as they offer more braking power and wear more evenly. We advise that you do not attempt to convert a bicycle with rim brakes to electric, as with the increased power and speed associated with having a motor, you will wear the rims out faster than on a non-electric bike. Ultimately this will mean replacing the rims via a wheel build, or replacing the wheel entirely. Disc brakes are better suited to eBikes as when the
discs wear out, you can simply replace them rather than the rim/wheel. This is far more cost effective.

2. Strong frame and fork – A lightweight racing frame that was not designed to be loaded is a poor candidate for electric conversion. The additional forces introduced by the motor’s torque and supporting a battery may stress the frame or fork to failure. A bike designed to carry heavy loads (e.g., a cargo or touring bike) or withstand high stresses (e.g., a mountain bike) is a better candidate.

3. A spot for a battery – The battery tends to be the largest and heaviest part of an electric bike conversion kit, so making sure your bike has an appropriate place to mount it is vital. Many kits are designed to make use of pre-existing bottle cage mounts on a frame. If your bike doesn’t have these, or not enough room for a battery where there are mounts, then you need another solution. One option is a frame or handlebar bag, though use of these will require the purchase of a bag, appropriate space for the bag, and long enough cables from
the battery to the rest of the system. They also tend not to be fully rigid, causing the battery to flop around which may cause issues. Another option is a rear rack which the battery can be mounted to. While more rigid, this option still incurs further costs, you may run into cabling issues, and modifications to the rack may be required.
Note: These criteria are not exhaustive. There are a number of other issues to consider regarding compatibility. These are touched on below.


What type of eBike conversion kit is the best?
The best electric bike conversion kit for you will depend on a number of factors. Conversion kits tend to be composed of a battery, controller, display, controls, and motor. While each of these components is important, those that require the most consideration are the battery and motor:

Battery: The two biggest considerations for batteries are size and shape. For a given motor, the larger the battery’s capacity the longer it will last. Reading reviews will help you gauge what capacity you require. It’s important to remember, however, that a battery with larger capacitance will likely
mean a larger case. Make sure that you’ve considered how the battery will mount to your bike and whether or not it will fit.

Motor: Most conversion kits use either front motor wheels or mid-drive motors. For moreinformation on the difference between these options, check out our article on electric bike motor types. Unlike ready-made eBikes, when considering what motor is best for you you’ll also have to consider compatibility. There are too many kits available on the market to be specific here, but there are a few general considerations to be had. When researching front motor wheels, you’ll need to make sure the wheel’s diameter, hub spacing, and axle size fits your bike. You’ll also need to make sure the brake system is compatible with your bike’s forks and brake setup. When researching mid-drive kits you’ll need to make sure that you’ll still have enough clearance underneath the bike for the riding you’ll be doing, the kit is designed to fit your bike’s bottom bracket size, and you have an appropriate bottom bracket removal/install tool on hand. Mid-drive kits tend to be more difficult to install, so bear that in mind. The problem with ‘universal’ conversion kits: We have experience attempting to fit ‘universal’ kits to bikes that ultimately weren’t compatible. This was despite the kit manufacturers claims about universality, and even with direct confirmation
of compatibility with particular customers’ bikes.

There are two main issues with ‘universal’ kits:

1. There is a wide range of variability between bikes, with many different manufacturing standards existing between bicycle type, country, and time. This makes true universality impossible.
2. Many issues aren’t possible to spot until work has begun. If you are getting the kit fit by a mechanic, this could mean incurring a labour cost even if the kit is ultimately not compatible.

Does Glow Worm do electric bike conversions?

Our Sydney and Melbourne workshops convert non-electric bikes to electric on a case by case basis.

Give us a call on 02 9569 9126 (Marrickville) or 03 8577 8189 (Collingwood), or email us at info@glowwormbicycles.com.au to discuss your options.

The Alternative:

A decade ago there were very few eBikes on the market, with early adopters resorting to DIY conversions. Today there are a wide range of readily available eBikes, designed as eBikes from their inception. These bikes have neatly integrated batteries, stronger framesets, and harder wearing components, as well as guaranteed functionality and serviceability. Not only that, but they also
benefit from the cost savings of batch production. This means that they often work out costing less than a converted electric bike once you’ve accounted for the bike, kit, and labour.

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