Display/console - An electric bike should have a console for displaying crucial data such as distance covered, speed, battery level, and assistance level. I’ll also mentioned that Tongsheng’s firmware (ie the code that tells the motor how to behave) is a little weird. In particular, you get maximum assist at an oddly low cadence – about 60. It then tails off until at about 100 RPM you get very little help at all. This is not intuitive if you’ve mentally programmed yourself to spin up hills to stop your knees exploding; I sometimes need to change up to a harder gear if I want more help on a hill (this only works if you’re not already getting the max available power from the motor. If you are, then you need to change down to keep going. You’ll get the hang of it after a few weeks, honest). The Tongsheng TSDZ2 is one of the best e-bike conversion kits available, but it will not be for everyone. Installation can be challenging, and the motor may need periodic maintenance. It is an excellent option, resulting in a bike that looks and rides more like a factory-produced e-bike. If you have a mobility reduction or impairment, you should opt for the TSDZ2T which is the TSDZ2 with throttle which helps climbing hills without extra work. Finally, I’ve fitted the 48V, 250W version of the TSDZ2 (ie EU-legal), with the factory firmware. It’s paired with a 12Ah battery. Is the TSDZ2 as good as a dedicated ebike?

The pedal placement width is more significant than average (which is a disadvantage to the feet rotating the pedals for movement) However, another big opportunity with the TSDZ2 is there’s a very active open-source firmware build available. This allows you to tweak a whole range of values (and sorts the diminishing-assist-with-increasing-cadence issue I mentioned earlier), add in a walk-assist mode, and apparently makes it feel like a completely different motor (in a good way). However, you must not fit a bigger ring than 44T. The TSDZ2 has 42T ring, maximum 95RPM. On bikes with cassette and 700C wheels, that is 30 mph.

More responsive and intuitive pedal assist feel – some say this brings the feel of the motor closer to that of the expensive Bosch system.

Absolutely. I’ve already recommended it to a couple of people. In fact, I’d go so far as to say the only reasons not to go for a retrofit kit would be:

Levels of support - With the levels of support ranging from 3 to 9, you get to choose the level of assistance depending on your pedaling efforts and roughness of the terrain.

If you just want an off-the-shelf, buy-it-and-ride-away, no-maintenance-needed ebike. Nothing wrong with that; it’s not as if you would be asked to fit the engine to your car after buying. Enhanced cycling experiences facilitated by the torque sensor, which adjusts to the amount of force applied to the pedals

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The option to be able to use different displays. For example, the KT-LCD3, as is the colour Bafang P850c display, is commonly used.

Motor type - Mid-drive motors have a higher capacity for hill climbing while hub motors (which are inefficient on hills) work well on flat, consistent terrain. At the moment, Bosch and Shimano motors have a two-year warranty from new. After that, if you get a fault, you either live with it or get a dealer to buy and fit a replacement motor (and from what I can tell it has to be exactly the same motor model – no upgrading). It’s not entirely clear how that process works, or whether dealers can get hold of spare parts, or just entire motors. Because this is a mid-drive unit, the assistance is much more subtle than rear or front wheel drive units. The power is blended in much more smoothly and I imagine would be much less disconcerting to a rider not used to an e-bike. No, it’s resistant to water and can be ridden in the rain, but I would avoid puddles. Will the TSDZ2 fit bikes with thru-axles? How far does the TSDZ2 go on a single charge? This will vary greatly depending on rider fitness, terrain and many other factors. My conversion used a high-quality 36v 13Ah battery, and I could squeeze nearly 100 miles out of a charge using ECO mode. This is an exception, though, as I was training to lose weight and get fitter. A realistic range for this kind of battery would be about 50 miles.Range - Since speed helps determine the range an e-bike can cover, it will take more battery power to travel at a higher speed than a lower speed. Range may also vary with the terrain, motor type, and weight of the bike. Big flip-side to this: at least Bosch/Shimano stuff does come with a manufacturer’s warranty, and is better built and far less likely to break in the first place. This isn’t much comfort if you’re having motor problems, but let’s not pretend that it’s all roses with Tongsheng.)