Kits Vs Turnkey


In the initial days of the ebike movement you almost had to make your own ebike from scratch to get decent performance. The options for turn-key electric bicycles in the early 2000's were limited, with poor range and power, clunky aesthetics, and questionable craftsmanship. The only way to get a proper looking bicycle with power assistance was to build-your-own around a modern bike platform, often using batteries, motors, and electronics taken from other industries such as PowerTools, RC Hobby vendors, and so on.

During this founding period, many early adopters came to Grin for kit components simply because what they could build from scratch was substantially better than buying a turn-key solution. Today, however, the options for turn-key ebikes are phenomenal and expanding each year. You can purchase most common types of bicycles, including cruisers, cargo, mountain, commuter, road, fat, folding and so on, ready to go in an electric variant, and all in a range of prices and quality to suit many different budgets. In general, these factory ebikes will have reliable and sophisticated electronics, dependable lithium batteries, a smooth control system with a nice display and tightly integrated wiring.

So Why Build an Ebike?

Even though turn-key ebikes solutions abound today, electric conversion kits still have a bright and understated future and will continue to play a major role in the movement towards personal electric transport. At Grin, we believe that conversion kits designed around open standards will fit into the long-term bike industry model better than factory ebikes. In spite of the wide assortment of good quality turn-key electric bicycles to choose from, a setup based on retrofit kits offer several advantages that might not be apparent up front. Here are 8 reasons why people still go the kit route.

#1. You already own your ideal bike

The first reason many people go looking for a conversion kit is because they already own a perfect bike that has been personalized to their needs, but want an upgrade to electric assist. It makes little sense for them to buy an entire pre-built electric bike when they already have a great bike for the task. Converting an existing bike will be less expensive, since the costs are limited to purchasing the electric components, and will guarantee a bicycle platform that's been proven to fit.

#2 The ebike you want doesn't exist

Although there are plenty of prebuilt ebike options now, they still don't cover all the variations and needs of different people. Turn-key producers tend to focus on major markets such as mountain bikes and commuter bikes, or trendier markets like beach cruisers and fat bikes, or cargo bikes where electric power is largely necessary.  Their offerings also tend to fall within a common window for power, range, and speed.

If you have specific requirements related to hill climbing power, or cruising speed, or maybe you need a bike that can reach an extended range, then these might not fit the bill. Cyclists who are into niche vehicles like recumbents, tadpole tricycles, handcycles, or velomobiles face a similar situation. A conversion kit allows you the flexibility to make exactly the ebike that you want even if it doesn't exist on the market.

#3 DIY is in your blood – you can build your dream bike

Our customers include countless inventive people working on all kinds of wild, original, and exciting projects based around our ebike hardware. For these people the entire point is to make something new from scratch. It's a similar motivation to people who sew their own clothes, build their own furniture, or machine their own steam engines.

Converting a bike to an ebike can be a rewarding hands-on learning opportunity that mixes electronics, mechanical assembly, and power, where the output of your project becomes something you can actually ride. Ebikes are a DIYers dream. Whether your project is for creative expression, or learning cutting edge technologies, we love it, and Grin is here to help make that a reality.

#4 You can move a kit from one bike to another

Another benefit of the conversion kit over a turn-key ebike is the implicit ability to move the entire electric drive over to a new bicycle platform. As you outgrow your current bike or your cycling needs change, you can usually move the kit over to to your new setup, and revert the original platform back to being a perfectly good non-electric bike.

We've had customers running the same hub motor for 15 years having migrated it across numerous platforms, re-lacing it from a mountain bike rim, to a road rim, and then to a small recumbent wheel rim. Other customers have a vague idea of an ideal electric bicycle build that they want in the future, but are keen to get started with what they have now. A conversion kit allows them to get their initial bike electrified and then have it evolve into their dream ebike as ideas develop and budget allows.

#5 Future Upgradeability

With a conversion kit bike based on open component standards, you have any number of options to upgrade components as your needs evolve. As new technologies in battery density, motor controller performance, and pedal assist control schemes become available, you can upgrade the associated parts on your ebike. If your commuting distance increases, you can hook up another battery in parallel, if your speed requirement changes, you can swap out to a higher voltage battery pack. If you need more torque from the motor, you might be able to simply upgrade to a higher current motor controller.

A conversion kit ebike is ripe and ready to swap-in future and better technologies as they become available. With a turn-key ebike, it's rare that you will be able to deviate from the stock performance without some deeper level hacking that the manufacturer will often go out of their way to complicate.

#6 Flexible Battery Solutions

Factory ebikes are usually designed with a custom formed battery pack that fits elegantly into a custom cavity on the frame. Out of the box it looks smart; but there is only that one make and model of battery pack that is a drop-in compatible to that bike. You can only hope that the ebike manufacturer will continue to produce that battery model, and make it available at a reasonable price. Without a battery, an ebike isn't much of an ebike. Most conversion kits, meanwhile, are based on a premise that the battery is a black box power source. By their nature, kits can work with a wide range of battery options.

One thing we can tell you about any ebike is that the battery will eventually need replacing. Early ebike packs would often reach end of life in two to three years. Today's lithium batteries can last four to six years or longer, but at some point for sure, the battery will wear out.

With a factory ebike that is out of production, either you'll need to find a custom pack manufacturer who can open up and replace all the cells in your original battery casing with new cells and migrate the battery electronics in the process, or you have to hack the ebike to work with a 3rd party external battery somehow, leaving the custom frame cavity empty and no longer looking so elegant. With a conversion kit it's usually no problem replacing a battery. You can see what new batteries are available, and choose one that fits where you want it to go, your frame, your bike rack, your saddle bags and so on.

#7 Support

This point may not be obvious upfront. You would think that getting a turn-key ebike from a store would mean that you can take it back to that shop for service, while a DIY kit install would leave you on your own for any troubleshooting. The latter is generally true, though in the process of selecting and installing the kit yourself, you will learn many of the skills required to troubleshoot any problems; you will become your own support crew instead of needing a shop mechanic.

When purchasing ready to ride ebikes, the long term support can be very tenuous. Many shops that retail ebikes have little technical knowledge of how the system works or how to service components. Instead, they are dependent on the manufacturer to supply replacement parts and look after warranty work. In the first few years after purchase this service model generally works fine, but it starts to break down beyond the five year mark.

Does the shop that sold the bike still exist? Does the manufacturer still make compatible replacement parts for that particular model? Does the manufacturer even still exist? We've been in this industry long enough to see countless ebike companies come and go, with only a few lasting more than five years, and fewer still surviving to the ten year mark. Even those companies that were thought to be well backed and financed can suddenly disappear leaving tens of thousands of customers with an unsupported proprietary system.

With an ebike built from a conversion kit, you learn how the pieces fit together through the process of installing the package. You will have a much easier time finding compatible replacement components if parts fail over time. Plus, your bike still contains regular bike hardware, such as the drivetrain, brake pads, shifters, parts all still easily found at any bicycle store.

#8 Proprietary Controls and Components – bikes can outlive companies

In our opinion, the single biggest issue with most ready to ride electric bicycles, especially the more premium models from a brand name, (for example Bosch, Yamaha, Specialized, Shimano, etc.) is that they are designed around proprietary mechanical components and electric communication protocols. Everything may look slick and neatly integrated out of the box, but that tight integration almost always comes with a price tag on flexibility and support life.

Imagine you purchased one of the first generation Bosch Classic+ ebikes. The entire mechanical drivetrain for the pedals is packed inside custom gearbox and motor assembly that is mounted to a custom frame interface on the bicycle. If the gears wear out and need replacing, the crank freewheel pawls stop engaging, the motor controller fails, or any number of other problems crop up, your only solution is to get that exact replacement part from Bosch. But guess what: Bosch has moved on to their newer active and performance lines no longer making the Classic+ model or supplying parts for them. You have a troubleshooting problem, but unfortunately the system is well out of warranty and the damaged part no longer available.

Surely then, you can at least upgrade the bike to use Bosch's new active model, replacing the entire drive (motor, battery, controller, cranks, display and all) even though it's only just one of those parts which failed? Sadly no, as the actual frame interface has changed too. That new Bosch drive will not physically fit on your bike frame that was designed around the Bosch Classic+ system. And in fact, no other commercial mid-drive kit will fit on it either. Your bike frame is engineered around one specific product interface that is now discontinued. What should be a perfectly fine bike with plenty of life left is now all but useless because of one failed component. This is not a hypothetical situation, this is exactly what many people who purchased factory ebikes five-to-ten years ago are facing right now.

Traditional bicycles have a wonderful history of lasting through multiple decades and even generations, with industry settling on a few component norms that are broadly standardized and available from multiple sources. If you dust off an old Schwinn cruiser from the 1960's or a road bike from the 1970's or a BMX from the 1980's or a mountain bike from the 1990's, you can still get any needed components to keep riding that bike today. Bikes typically out-live the companies that make them, and we think ebikes should last the same way.

This store does not existInstead, factory ebikes are moving in a different direction that looks like the automotive industry, where every make and model of vehicle has a unique list of custom components. In order to do repairs after the warranty period we would need a shop like NAPA that stocks over a million specialized parts to replace all the proprietary pieces out there. It's either that, or ebikes will be treated like expendable consumer electronics, to be tossed and replaced rather than repaired.

We don't look forwards to either of those scenarios. There is no specialty supplier for model specific ebike parts, and there is no point in electric bicycles being tossed into the scrapyard for one failed proprietary component. If you have a conversion kit built with open part standards, there is no dependency on a specific company. You'll be able to upgrade to different batteries, motors, or motor controllers if parts wear out. Your bicycle can always be upgraded mechanically since it started off as a standard bicycle using standard bicycle hardware. And you can always remove the electric and go back to riding it as a regular bicycle again.

Though this reason is #8 on our list, it's the #1 reason in our hearts for why we're staying in the kit industry and are excited to keep advancing the quality of parts available for aftermarket conversions.

[Edit from 6 years after writing article] We've finally been seeing more and more mainstream feedback about this issue with factory ebikes, ex:


We hope this article is helpful in developing your understanding of why Grin is committed to kits, and helps you in your decision process in whether to buy a complete ebike or a kit. We're under no illusion that a majority of potential ebike riders will want to purchase ready-to-ride electric bicycles and we hope to see that industry continue to thrive, but ideally thrive in a way that takes the long long term view of support and product life beyond just the two year warranty window. For us though and the reasons outlined above, we're all about the kits. Always have been, and always will be.

*(It should be noted that there are some turn-key ebikes which are quite versatile and easy to upgrade. The hub motor ebikes from companies like Rad Power, Pedago, and Juiced would tend to fall in this category, as they are effectively built like a conversion kit on a bike. Similarly there are some conversion kits which are quite proprietary and locked down, like BionX or the Copenhagen Wheel.)