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If you have a decent but unloved bike sitting in your garage, it may be worth turning it into an electric bike using a Tongsheng TSDZ2 conversion kit. In this review, I’ll go over the pros and cons of this affordable alternative to buying a new e-bike, and see if it’s worth the hassle converting a bike you already have.

I have personally installed over thirty of these kits in recent years and have found the long term reliability to be no better or worse than other similar e-bike motor kits like the Bafang mid-drive.

Tongsheng TSDZ2 Specs

Motor PositionMid-Mounted (Bottom Bracket)
Motor Compatibility68-73mm BSA Threaded Bottom Bracket
Rated Motor Power250-watts to 500-watts
Motor Peak Power576-watts to 768-watts
Max Torque80Nm
Motor Rated Voltage36-volt or 48-volt
Controller Current 16-amps
IP RatingIP54
Price $300 – $400
AvailabilityVarious online retailers

Tongsheng TSDZ2 Pros and Cons

Pros

  • Very efficient
  • Torque-sensing pedal assist
  • Smooth power delivery
  • Plug and play installation
  • Good value for money

Cons

  • Limited clearance between motor and BB
  • Not compatible with some frame designs
  • Blue nylon gear can wear
  • Not very waterproof

How does the TSDZ2 work?

It’s a mid-drive motor that fits where your bike’s bottom bracket would be (central bearing that crankset fixes to). The motor draws energy from the battery which in turn drives the rear wheel via the bicycles chain. A torque sensor inside the motor measures the force you are putting through the pedals and provides electric assist in relation to how much force you apply (and pedalling cadence).

This extra power being transferred to the rear wheel is what gives the rider the assistance. The best way to describe it, is like pedalling up a steep hill with someone giving you a good push from behind. A 10% gradient suddenly feels like a gentle slope!

Tongsheng TSDZ2 mid drive motor installed on a hybrid bike
Tongsheng TSDZ2 fits in the bottom bracket shell and drives the rear wheel

You have up to 4 levels of pedal assist to choose from – ECO / TOUR / SPEED / TURBO. This means you can select the best level of assist to suit your needs and terrain. Because the torque sensor is so sensitive to rider input, you always feel like you’re getting the right amount of help.

Are all Tongsheng Motors the Same?

The Tongsheng TSDZ2 is generally sold in six different configurations: 36v 250w / 350w / 500w and 48v 350w / 500w / 750w. I have contacted Tonsheng for clarification on this, and have been informed that all the motor variants have the same internals / electronics. The only thing differentiating the 36v and 48v versions is the controller firmware programming. If you buy a 48v 500w, you are not getting a beefier motor or controller. It’s effectively the same as a 36v 250w motor, just with different firmware.

tongsheng tsdz2 installation manual
All TSDZ2 motors are the same except for firmware settings

It’s worth mentioning that in 2022, Tongsheng released an improved version. This is called the TSDZ2B and features several improvements, but most notably a dual clutch system inside the motor which drastically reduces drag when the motor isn’t in use. The blue gear issue has apparently been fixed as has the sprag clutch problem.

MotorBatteryPeak Power
Tongsheng TSDZ2 36v (250w variant)36v (42.2v x 16A)675w
Tongsheng TSDZ2 48v (500w variant)48v (54.4v x 16A)870w
The voltage figures in brackets are for a fully-charged battery. Note: As the voltage drops, so will the power.

The quick answer is yes and no. As I’ve mentioned above, all Tongsheng motors are the same, and are manufactured to the EN15194 European safety standard. What defines the legal parameters are the continuous power rating (250w) and maximum assisted speed (25 km/h). It’s okay to have a continuous output of 250w, but with a peak output (under load) of 500-600w. Indeed, most Bosch and Shimano powered e-bikes have these kinds of peak outputs in their maximum power setting.

is the tongsheng tsdz2 legal
Always check local laws before installing an e-bike conversion kit

Some resellers will limit the top speed of the TSDZ2 and others won’t. It’s your responsibility whether you choose to do this or not. Personally, I wouldn’t risk it as it’s your driving licence on the line.

In unrestricted form the Tongsheng TSDZ2 will go as fast as you can pedal. Using a typical 42t chainring with 11t high gear (on the back), the TSDZ2 will have a top assisted speed of 25 mph at a cadence of 80 rpm (near the maximum the motor supports). If you had a larger front chainring you could potentially go faster, but I wouldn’t recommend it! There’s more information in my article about UK Electric Bike Law.

Will the Tongsheng fit any Bike?

The quick answer is no. The TSDZ2 motor is only compatible with bicycles that have a BSA threaded bottom bracket 68mm-73mm. A lot of modern (high-end) mountain bikes and road bikes use a pressfit bottom bracket, which has a much larger internal diameter and is sometimes much wider than 73mm. If you are installing the kit to an older or less expensive bicycle, then you should be okay. But, it’s worth getting a second opinion from a qualified bike mechanic if you’re unsure.

Another problem commonly encountered is the modern MTB boost rear hub spacing which is 148mm as opposed to the old standard of 135mm or 142mm. This is to accommodate the wider tyres used on newer mountain bikes, but it means installing the motor could be very problematic.

full suspension ebike whyte 46
Fixing the TSDZ2 for this Whyte was challenging, but worth the end result!

One more issues relates to the way the motor is secured to the bike to prevent it pivoting. There is a clamp and 8mm fixing plate that requires a chainstay bridge just behind the bottom bracket shell. Most hybrid bikes, older hardtail MTB’s and road bikes will have this. But, full suspension MTB’s and some modern bikes won’t have this, so you’ll have no way of securing the motor (and will need to improvise).

tsdz2 bridge plate
Study this image. If your bike doesn’t have this design, then you’ll need to improvise.

The TSDZ2 is usually a good fit for recumbent bikes. I have installed this motor on several Ice Trikes with great success. Read my article on fitting an electric conversion kit to a recumbent trike.

Ice trike adventure recumbent with shimano di2 alfine 11 and tsdz2 electric conversion kit
The TSDZ2 is a particularly good fit for recumbent trikes

Can I install the Tongsheng on a Carbon Bike?

It may be possible on some carbon frames. But, due to the securing issues mentioned above and the risk of cracking the carbon, I really wouldn’t recommend it. I would find a good aluminium or steel framed donor bike instead. Most road bikes and some hybrids have carbon fibre front forks – this wouldn’t present any problems and shouldn’t be effected by the motor installation.

Is the TSDZ2 easy to Install?

The answer to this really depends on your abilities. Installation requires a certain degree of mechanical prowess, and it’s recommended to use the services of a bike shop or specialist if you’re not confident of doing the job yourself. The Tongsheng TSDZ2 comes as a kit, either with or without a battery (depending on supplier) and always includes a lockring tool for tightening the motor.

tsdz2 installation
The motor unit fits into the bicycles bottom bracket shell

Installation requires removal of the crankset and bottom bracket. You will need the correct tools to do this job, depending on the kind of bike you have. As the Tongsheng uses a torque sensing system, brakes with cut-off sensors are not required, reducing the need for more untidy external wires.

You may need to re-route the gear cable and brake hose/cable if they’re routed underneath the bottom bracket. The reason for this is poor motor design which leaves very little room for cables.

Once the motor has been installed, it’s just a case of fitting the display, battery, speed sensor and plugging in the connectors. Finally, tidy everything up with cable ties or adhesive clips. Sometimes there are redundant cable guides on the frame you can use. I have uploaded a PDF TSDZ2 installation manual which explains the process in more detail.

Can you Program a TSDZ2?

Yes, the Tongsheng TSDZ2 can be programmed by the end user. Although, the process is more complicated (than with the Bafang) and requires a certain degree of technical skill. The main route used is through OpenSource software. Plus, you will need to buy an ST-Link V2 which is an in-circuit debugger and programmer.

st link v2 for programming tongsheng tsdz2
The ST-Link V2 is a communication device required for reprogramming the TSDZ2

What are the Benefits of Programming the Tongsheng?

Lots of anecdotal reports suggest that re-programming the Tongsheng TSDZ2 has many benefits. I have listed the key improvements below:

  • Greater motor efficiency – more power, whilst reducing battery consumption.
  • More responsive and intuitive pedal assist feel – some say this brings the feel of the motor closer to that of the expensive Bosch system.
  • Improved reliability
  • Cadence support at higher rpm – the stock model stops assisting near 90 rpm. With reprogramming you can have assistance all the way up to 120 rpm pedalling speed.
  • The option to be able to use different displays. For example the KT-LCD3 is commonly used, as is the colour Bafang P850c display.

From the research I’ve done so far, re-programming the TSDZ2 can totally transform the motor. I would only recommend doing this if you are comfortable tackling to job yourself. You will void the warranty of the motor and if it’s done incorrectly you could end up with a blown controller.

Tongsheng TSDZ2 Common Problems

How reliable is the Tongsheng TSDZ2? Going by my own personal experience, I’ve found the TSDZ2 to be generally reliable for day to day use. I have installed over thirty of these motors and used one myself for many months without issue. I have had to replace the blue nylon gear on a couple of conversions and had one isolated problem with a torque sensor. Below, I’ve listed the common problems associated with the Tongsheng.

  • The blue nylon reduction gear can be prone to premature wear, although this seems to hinge on how hard the bike is being ridden and is unlikely to be a problem on commuter or leisure bike. ***The newer TSDZ2 ‘B’ has a different system and Tongsheng claim to have rectified this issue.
tongsheng tsdz2 nylon primary gear replacement
The blue nylon gear that may need replacing after some use
  • Torque sensors convert a torsional mechanical input into an electrical output signal. The main culprits are a poor solder on the sensor, cracked sensor rings or splits in the main torsional tube (that runs between the cranks). Replacements are readily available.
Tongsheng TSDZ2 replacement torque sensor
The torque sensing unit can occasionally fail
  • Controller failure – the TSDZ2 doesn’t like prolonged load and can overheat, particularly on long, steep hills.
Tongsheng TSDZ2 motor controller 36v / 48v
The motor controller may sometimes overheat on long, steep climbs
  • The ‘Sprag clutch’ or one way bearing has also been known to fail occasionally. ***This issue has been rectified with the latest ‘B’ model.
  • Water ingress – although water resistant, I wouldn’t recommend riding in heavy rain and certainly not through deep puddles.

Generally the TSDZ2 is reliable. But, problems can and do occur. Sometimes these may manifest within the first few miles and others may not happen until the motor has over a thousand miles under the belt. Environmental factors seem to play a part and if you live in a wet country, it’s worth remembering that the Tongsheng isn’t waterproof.

TSDZ2 Pedalling Resistance

Having ridden both the TSDZ2 and Bafang motors back to back, I always found the Tongsheng had less drag when the motor was off. Although, apparently this did vary from motor to motor, with some riders reporting significant resistance. It’s worth noting that a motor and battery combo will add around 7.5kg to the weight of a bike. This in itself will add to the effort when not using electric assist.

Thankfully, in 2022 Tongsheng have addressed this issue, and the latest ‘B’ version of the TSDZ2 has modified internals with a dual clutch system. I’ve yet to test one of these motors, but early reports suggest a great improvement.

TSDZ2 vs Bosch

If you’ve been thinking of splashing out on a new e-bike, one of the most common motors used on e-bikes in the £2000+ price range is the Bosch motor. This motor represents the pinnacle of electric bike motor engineering and comparing the TSDZ2 with the Bosch is a bit like comparing chalk and cheese.

tsdz2 vs bosch
The TSDZ2 is great for the money, but it’s not as refined as the mighty Bosch!

While there are similarities. If you go straight from a Tongsheng to a Bosch-powered e-bike, you’ll notice that the Bosch motor is so much smoother and more refined. On top of that, you have Bosch’s legendary reliability and 2-year warranty. Having said that, when you consider the price difference, the TSDZ2 isn’t that bad. Plus, if you fancy having a go at re-programming the Tongsheng, many riders report almost achieving Bosch like refinement and efficiency for a fraction of the cost.

What is the best alternative to the TSDZ2?

If you’re reading this you are probably familiar with the Bafang mid-drive conversion kit. I really like the Bafang and have installed more of these than any other motor. Although the Tongsheng and Bafang share similarities, once you get beneath the skin the two motors are quite different.

tongsheng tsdz2 alternative
The Bafang BBS mid-drive motor is a good alternative to the TSDZ2

Whereas the TSDZ2 uses a torque sensor, the Bafang uses a cadence sensor giving the motor a very on/off feel. The Bafang is much quieter, almost silent. But, it’s heavier, more expensive and just as prone to technical faults. For more information, please read my Bafang vs Tongheng comparison article.

What’s included in the TSDZ2 conversion kit?

what's included in the tongsheng tsdz2 kit
  • The motor unit with integrated controller
  • LCD Display – VLCD5 / XH18 / VLCD6
  • Wiring loom
  •  Inner and outer lock-nuts
  • Chainring 42T
  • Speed sensor and wheel magnet
  • A bag of various Allen bolts and screws
  • Installation tool / spanner

What display is best for the TSDZ2?

This is a personal choice, but for me it’s the VLCD6. It is very small and has limited functionality, but it’s discreet and looks neat. The VLCD5 has lots more functionality but it is quite large and fits straddling the handlebar stem. Finally, there’s the XH18 which fits near the left hand grip. It’s quite bulky but does have good functionality.

which is the best display for the tongsheng tsdz2
These three displays are offered as standard. My favourite is the VLCD6

What’s a Tongsheng E-Bike like to Ride?

In short, the Tongsheng provides a great riding experience. I have ridden countless e-bikes over the past six years and installed my first TSDZ2 back in 2018. Later that year I fitted a Tongsheng conversion kit to my Decathlon BTWIN 900 hybrid bike and used it for a good six months.

The torque sensing pedal assist works really well, and having ridden Bosch e-bikes, I would say the power delivery is very similar, although nowhere near as refined. The general feel of the assist, is one of an enhanced cycling ability, you still have to put in an effort but it makes you feel like you have bionic legs, which is great fun!

BTWIN riverside 900 Hybrid bike fitted with a tongsheng tsdz2 mid drive electric bike conversion kit
My TSDZ2 conversion kitted out for a long distance ride

How far does the TSDZ2 go on a single charge? This is going to vary greatly depending on rider fitness, terrain and lots of 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.

One more thing that’s relevant to the riding experience is the Q-factor – it’s a bit too wide for my liking. The Q-factor is the distance between the pedal attachment points on the crank arms, when measured parallel to the bottom bracket axle. On the TSDZ2, the Q-factor is quite wide at 210mm.  If this is a problem, it can be easily solved by fitting a pair off standard Bafang BBS  or Shimano Steps FC-E6000 cranks arms which should reduce the above figure by 28mm.

Tongsheng TSDZ2 fitted with shimano steps fc e6000 crank arms

Who is the TSDZ2 Best Suited For?

If you prefer the natural feel of torque sensing pedal assist, then the Tongsheng is the only viable option. Nothing else comes close when it comes to plug and play conversion kits. It’s not a free ride though, and you will need to add some effort for the motor to perform its best. If you want something faster and more effortless, then you’d  probably want something like the Bafang BBS02B – which offers outstanding performance with little to no effort.

The Verdict

The Tongsheng TSDZ2 is one of the best e-bike conversion kits available. Bit, it will not be for everyone. Installation can be challenging and the motor may need periodic maintenance. It is nonetheless an excellent option, and the end result will be a bike that looks and rides more like a factory produced e-bike.

The torque sensing system may not suit everyone, as you will still need to put a fair amount of effort in for the pedal assist to work. But for me personally, I love the way it provides assistance. My only real complaint, is that I generally ride my bike at a higher cadence of between 80-100 rpm, and this motor does not provide any assistance beyond 90 rpm. Although, this can be altered if you’re brave enough to have a go at reprogramming.

decathlon bike fitted with tongsheng tsdz2 conversion
Building your own electric bike is a very rewarding experience!

In 2022, the Tongsheng TSDZ2 is still quite a bit cheaper than the Bafang, making it excellent value for money. Read my Bafang vs Tongsheng  article for more info.

If you are comfortable with your ability to install it, and you have an appropriate donor bike, then as long as you can live with some of the compromises, this is an excellent electric bike conversion option and an excellent alternative to the Bafang. There is also a good supply of spare parts available.

Where can I buy the Tongsheng TSDZ2

The Tongsheng is a very popular e-bike conversion kit and is available from various online retailers in multiple countries. Prices vary depending on where you live, but I’ve always found Aliexpress to be the cheapest. If you’re concerned about potential problems and want the easy returns route, then I’d be inclined to buy from Amazon or eBay as these platforms make the returns process very straightforward.

Amazon
eBay
Aliexpress
Check the Latest Prices at ebikepricecomparison.com
Links to Buy the Tongsheng TSDZ2

Thanks for reading my Tongsheng TSDZ2 review. If you have any questions relating to the Tongsheng motor, please feel free to leave a message in the comments section below. Or head on over to my TSDZ2 Forum where there’s over 400 posts from the last 4 years.

Tony

Passionate E-Bike advocate and enthusiast since 2016. Riding an electric bike helped me to lose weight, get fit and reignite my passion for cycling!

Tony has 228 posts and counting. See all posts by Tony

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