I've been looking to reduce how much I sweat on my commute to work, and I've been looking into electric bicycles. Upon looking, I saw the copenhagen wheel: an all-in-one electric bicycle conversion kit. I'd prefer to go with the most cost efficent method. Does anyone have any experience with it? Is it more practical to buy a complete electric bike or to use a conversion kit?
Some of your questions are not answerable, so I will only focus on what can be answered.
Does anyone have any experience with it?
No one has any real experience yet as the wheels are still on pre-order. A friend pre-ordered nearly 2 years ago and is still waiting. That said, you live near their headquarters (Cambridge, Mass) apparently you can demo a unit.
Is it more practical to buy a complete electric bike or to use a conversion kit?
This depends on what you mean by "practical" and what your use case is. If you are planning on long distance commutes (e.g., 40+ km) with a high assist level, then it will not be practical as the battery housed within the wheel may not provide enough range.
If by "practical" you mean easy to convert an existing bike, the answer could be yes if your bike matches their required specs.
For geared bikes your will need rim brakes on the rear wheel (no disc brakes) and a rear hub spacing of 135 mm (road bikes are 130mm and will not work unless you spread the frame - difficult and requires steel frames). If you are fixed or single speed your rear spacing will need to have a standard track hub spacing (120mm).
You will also need a smart phone in order to interact and change the settings on the wheel.
If any of these are a deal breaker then it is not practical for you.
In terms of pricing it is very competitive relative to existing electric bike or existing conversion kits. Assuming it actually ships and works as advertised.
NOTE: For those unfamiliar the Copenhagen wheel is self contained (battery and motor are housed within a large hub) rear wheel which you swap out on an existing bike. Assuming your bike (or bikes) is compatible, this makes turning an existing bike into an electric bike a relatively quick and straight forward conversion. All controls are done via a smart phone application and bluetooth
If money is of little consequence, by all means, acquire an electric bike for your work commute and keep your current bicycle as it is. The electric bike is more likely to have a longer lasting battery and integrated controls.
The conversion kit on the other hand, will be less expensive and could probably be swapped between multiple bikes. It seems like a generally more convenient route.