Bafang BBS02 Review – How Reliable is it?

Introduction

Hello and welcome to my review of the popular Bafang BBS02 mid-drive electric bike conversion kit. This review is based on my own personal experiences installing over sixty of these units over a two-year period. I really like the Bafang and it is an excellent motor, but like all things electric there are a multitude of gremlins that rear their head from time to time – this is definitely not a motor to fit and forget!

At the bottom of this article are links on where to buy the Bafang BBS02.

bafang bbs02 750w motor

Overview

The Bafang BBS02 is available in three different configurations: 36v 500w / 48v 500w and 48v 750w.  The 750w version is the most popular as it offers the most bang for your buck!  The motor itself is physically the same as the lower powered BBS01 250w / 350w, the only difference being the internals and controller. The installation criteria is the same as the other Bafang units for the classic 68mm-73mm bottom bracket fitment, this motor is not available in wider bottom bracket versions of 100mm and 120mm as with the BBSHD.

Pressed fit bottom bracket compatibility

As with all the Bafang e-bike kits, there is the potential to install it on a full suspension or hardtail mountain bike that uses a pressed-fit bottom bracket, although you will need to purchase the correct shim adaptor kit and motor stabiliser bar, or if you know a good engineer, you could get one fabricated. This is not a job to be taken lightly, but it is possible if done correctly.

Legal Information

If you are not familiar with e-bike law, in your country, it is worth checking beforehand. The Bafang BBS02 750w is legal in the US, but not road legal in the UK, EU or Australia, as the power output is rated at between 500w-750w. Peak power is substantially higher – up to 1470w on the 48v 750w model with a 52v battery fitted. If you are in the UK and planning on using this on private land, that is absolutely fine, but if you are going to use it on public roads then you should be aware of the potential legal implications first. Please read this post on UK/EU electric bike law.

This Electric bike kit comes with the following components:

  • The motor unit with integrated controller
  • LCD Display
  • Wiring loom
  • Inner and outer lock-nuts
  • Chainring
  • Plastic Chain-guard
  • Thumb throttle
  • Brake levers with cut-off sensors (only compatible with cable brakes)
  • Speed sensor and wheel magnet
  • A bag of various Allen bolts and screws

Bafang bbs02b 48v 750w mid drive electric bike conversion kit with battery

 

Installation

Installation of this motor is the same as other mid drive motors. If you are looking for a nice easy conversion to do yourself, but you have little or no experience with bicycle mechanics or using tools, I would not recommend this kit. See my guide on how to install a Bafang BBS02.  The installation will need to be carried out by someone who is fairly competent. Removing the bottom bracket on your bike can be a right pain, and you will require a lot of patience!

Technical Data

This electric motor produces considerably more torque than its smaller siblings (up to 120N.m), I have listed the peak power output for all the motor and battery configurations below:

BafangBatteryPeak Power
BBS02 500w 36v36v (42.2v x 25A)
1055w
BBS02 500w 48v48v (54.4v x 18A)864w
BBS02 500w 48v52v (58.8v x 18A)
1058w
BBS02 750w 48v48v (54.4v x 25A)1200w
BBS02 750w 48v52v (58.8v x 25A)1470w
The voltage figures in brackets are for a fully-charged battery. Note: As the voltage drops, so will the power.

I have listed the power output to include the 52v battery option, as this is quite popular, although I no longer advocate the use of a 52v battery with any of the Bafang 48v motors, due to reliability issues (please see below).

Like all the other BBS motors, the BBS02 uses an internal cadence sensor, and gives electric assist based on pedalling rpm. The pedal assist is very responsive, and can be fine-tuned using the 9 power levels available.

bafang dp c18 colour display

The motor kit is supplied with a thumb throttle, but I would  exercise caution when using this. Heat dissipation is not as good on the BBS02 as it is with the BBSHD and even the latest ‘B’ version of the controller (with the upgraded INRFB3077 MOSFETs) can be prone to premature failure when using a throttle inappropriately.

If you need to use the throttle regularly, it would be worth changing the throttle ‘start current’ settings in the controller firmware (you will need a compatible USB lead and software).

It is crucial to be in a low gear on steep hill climbs or starts, as subjecting the motor to unnecessary load can cause the controller to blow.

Personally, I am not a big fan of these throttles. They are not particularly good for modulating the power, and function more like an on/off switch, although reprogramming the controller can make the throttle more user-friendly.

As with all the other Bafang models, the controller firmware settings can be changed with a USB programming lead and software (which you can download for free here).  If you are doing this for the first time you should exercise caution and do your homework first. A good source of information on Bafang programming can be found on this excellent thread on Endless Sphere.

This kit is available with either a 44t, 46t or 48t steel chainring. If you are climbing lots of steep hills, I would definitely recommend an aftermarket chainring of around 36t .

One thing you will have to be aware of, if you do fit a smaller front chainring, the substantially lower gearing can make the bike prone to power wheelies, especially when hitting full throttle in a low gear on a steep hill start.

If you want to fit the brake levers with cut-off sensors, then bear in mind that these are only suitable for cable operated brakes. I would only recommend installing this kit on a bike with decent hydraulic brakes. Because this motor is so powerful, I would recommend the hydraulic brake cut off sensors or completely new hydraulic brakes with the sensors already built in.

bafang bbs02 750w mid drive motor installed on a full suspension mountain bike

Reliability

I have installed more BBS02 750w motors than any other (in excess of sixty units) and I have had a high rate of controller failure (17%). Whether this is down to the way the bikes are being ridden or the MOSFETs in the controller simply can’t handle the voltage and current, it is hard to say for sure. But there does appear to be a correlation between using 52v batteries and controller failure.

The 36v and 48v 500w version seems to be the most reliable, to date I have only had one controller failure on this model.

Can a 52v battery compromise reliability?

 

48v 17.5ah e-bike battery

A 52v battery when fully charged is at 58.8v, this is very close to the motor controller’s maximum operating voltage of 60v. I would personally stick with a 48v battery which is 54.4v fully charged. I have never had any issues with the motors that used 48v batteries. If you would still prefer to fit a 52v battery, then it would be worth buying a spare motor controller.

Having said that, I used a 52v Bafang BBS02 for a year and covered nearly 2000 miles, and I never had any issues – I later sold the bike, and it is still running well to this day!

The motor also uses a nylon primary gear, that can degrade over time. Replacements are easy enough to find, and there are plenty of good tutorials on YouTube for stripping this motor down.

Things to consider

  • For the 500w and 750w 48v models, I would personally stick with a 48v battery, as the power gained by using a 52v battery is minimal, and in my opinion is not worth the risk.
  • You will need a Bafang lock-ring spanner – the BBS02 will sometimes come loose due to the torque of the motor and may need periodic tightening.
  • The speed sensor can be easily knocked out of alignment with the wheel magnet – this will throw up an error code and pedal assist will stop working.
  • Some of the colour displays can be problematic – I find the black and white C965 display to be the most reliable, although the latest DP-C18 colour display seems to be pretty good.
  • I would definitely recommend fitting a Bafang gearshift sensor, with between 500w – 1470w going to the rear wheel, you will drastically shorten the service life of your rear derailleur, cassette and chain.
  • A heavy-duty chain is definitely recommended – there is a lot of torque going to the back wheel.
  • If you are planning on keeping the bike long term, it may be worth stocking up on some spare parts. It is always useful to have a spare controller and a nylon primary gear.

A demonstration of the gearshift sensor working, on a BBSHD powered bike

Riding a Bafang powered Electric Bike

The BBS02 is guaranteed to put a smile on your face – the days of being intimidated by steep hills are a thing of the past!

All of these motors are quiet and smooth running, I have ridden all three versions, and in my opinion, there isn’t a massive amount of difference between them in the lower power levels, it is only in the higher levels you really notice the extra power of the 750w version.

There is no doubt that in full power mode the 750w version is very quick, and a lot of fun to ride. Power-wise, there really isn’t a lot between the BBS02 and the BBSHD, although the latter has a lot more grunt, and the motor and controller can handle the extra power for a prolonged amount of time, whereas the smaller motor can become unreliable when subjected to constant hard off-road use.

Bafang BBS02 750w with 52 volt battery Installed on a Cube Aim Pro

Conclusion

As long as you are aware of this motor’s limitations, it is a fantastic piece of kit. If you constantly use it in full power mode, and use the throttle a lot, then it will inevitably let you down. I would advise you to purchase a spare controller or otherwise it may be worth spending the extra money and going for a BBSHD.

Install this kit on a decent bike, with good brakes and suspension and you will have a great high performance e-bike that is guaranteed to put a smile on your face!

I hope I haven’t put you off with this review, as I really believe this is a great electric bike conversion kit. As long as you can accept the potential long-term maintenance that will inevitably need to be carried out, it is well worth the money.

Below are some links to trusted Bafang BBS02 vendors that ship globally and also links to the motor kit from various Amazon locales. I have also compiled a list of parts.

Bafang BBS02B 48v 750w
Buy from Aliexpress GLOBAL SHIPPING
Buy from Amazon UK
Buy from Amazon USA
Buy from Amazon Canada
Achat d'Amazon France
Acquista da Amazon Italia

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Bafang BBS02 mid-drive Electric bike conversion kit

7.8

Value for Money

9.0/10

Ease of Installation

6.0/10

Efficiency

9.0/10

Reliability

6.0/10

Performance

9.0/10

Pros

  • Performance - The best bang for your buck!
  • Excellent Value for Money
  • Very efficient
  • Programmable controller
  • Neat and compact design

Cons

  • Does not handle abuse well
  • Can be difficult to install for the inexperienced
  • Expect to do periodic maintenance

13 thoughts on “Bafang BBS02 Review – How Reliable is it?

  • May 7, 2019 at 3:49 pm
    Permalink

    Hello. Is a BBS02 48v a good match with a Shimano Nexus 8. Thanks, Don

    Reply
    • May 7, 2019 at 4:54 pm
      Permalink

      Hi Don,

      You will be fine with a Nexus 8 as long as you fit a gearshift sensor and dial back the start current on the pedal assist (and throttle if you’re fitting one). I converted a bike for a customer over two years ago using a BBS02 750w on a bike with a Nexus 8, and it is still going strong at over 2k miles.

      You can find the Bafang software here and a good programming guide is available here.

      The programming leads are available from most Bafang suppliers on Aliexpress and Amazon.

      If you need any more info, please let me know.

      All the best,
      Tony

      Reply
  • May 15, 2019 at 6:00 pm
    Permalink

    Hi Tony,

    Thanks so much for all of your ebike reviews. I can’t afford the $3500 (I live in Canada) for a new Cube ebike so am considering a kit for my current bike which I love. Can you please give me your opinion on the best ebike kit for my Cube Attention SL (2017)? Is the BBS02 48v a good match?
    Spec:
    Chain set Shimano Deore FC-M612, 40x30x22T, 175mm
    Cassette Shimano CS-HG50, 11-36T
    Chain Shimano CN-HG54
    Brakeset Shimano BR-M315, Hydr. Disc Brake (180/160)
    Rims CUBE ZX20, 32H, Disc
    Hubs Shimano Deore HB-M615, Centerlock

    Thanks so much!
    Jo

    Reply
    • May 15, 2019 at 7:23 pm
      Permalink

      Hi Jo,

      Yes, the BBS02B 48v should be a fine fit. I’ve checked the specs, and your bike uses a Hollowtech II threaded bottom bracket. I have installed the BBS02 on several Cube mountain bikes including an Aim Pro and an Acid.

      The only thing I had to do on both these bikes is file away a small piece of the internal cable housing (where it meets the bottom bracket) in order to make the motor fit more horizontally. You haven’t necessarily got to do this, if you don’t mind the motor facing down at a 45 degree angle.

      It would also be a good idea to get a gearshift sensor. Thankfully, the latest Bafang motors have an extra lead coming off the controller, so should be able to install the sensor on the chainstay.

      Apart from the filing, the installations were straightforward. Here is the link to the supplier I use (including battery options). You would want to get the smallest chainring possible, they offer an alloy 42t alternative to the standard Bafang chainring which is 44t / 46t. You may need to adjuster the rear derailleur slightly to compensate for the offset, but I haven’t found this to be too much of an issue on the Cube.

      If you need any more advice, please let me know.

      All the best,
      Tony

      Reply
    • May 16, 2019 at 6:11 am
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      Hi Tony, great review and very well laid out with pros and cons. I know this might be a bit strange but I was wanting to get one of these and attach to an old school bmx just for some fun riding around the park and into the city. Maybe 15 k’s Max. Could you see any problems or have suggestions. Thanks Paul.

      Reply
      • May 16, 2019 at 8:21 am
        Permalink

        Hi Paul,

        Thanks for you comments, I’m glad you found the review useful.

        The main issue with fitting a mid-drive motor to an old school BMX would be bottom bracket compatibility.If yours has a standard 68mm threaded BB, then it wouldn’t be a problem, but if it has a one-piece crank or US type BB then you would need to find a good engineer who could machine a shim to take up the slack.

        The other option would be to get a hub motor laced into the appropriate wheel size – the main issue here is that BMX rear dropout spacing is usually 110mm and most hub motors are standard 135mm.

        You would also need a compact battery pack – my supplier does a 36v compact bottle battery that would do the job.

        If you need any more advice, let me know.

        Thanks,
        Tony

        Reply
  • May 17, 2019 at 12:46 pm
    Permalink

    Hi Tony, thanks for an awesome article. I am looking to install a motor in my felt f2 bike, do you know if it would fit?

    Reply
    • May 17, 2019 at 1:48 pm
      Permalink

      Hi Rob,

      Thank you for your positive comments.

      The Bafang or Tongheng mid-drive motor would not be a straightforward fit, as your bike has a FSA BB30 pressfit bottom bracket and the inner dimensions of the BB shell are 42mm. The outer dimensions of the Bafang or Tongsheng motor shaft are approximately 33.5mm.

      You can get a BB30 to BSA adaptor here, but you would still need to fabricate a motor mounting plate.

      If you can get the motor to fit, you may find the gear indexing not as good, as the Bafang motor has a slight off-set.

      If you need any more advice, please let me know.

      Regards,
      Tony

      Reply
  • June 27, 2019 at 2:30 am
    Permalink

    Hi Tony, thank you so much for this great and useful review! I just bought the BBS02 48V 500W to fit my 2015 Cannondale Trail SL 29 1, and i must say it looks great. Today i made my first ride to work (excuse my english, i am a french canadian) with it and it was perfect, but when i came back tonight, the chain dropped 5 times (during a 17 km ride)… I am not sure but i think it’s when i hit a hole in the street. I guess it is because my chain is too long and needs to but shortened? Anyway, thank you again. Christian

    Reply
    • June 27, 2019 at 8:22 am
      Permalink

      Hi Christian,

      Thank you for your positive comments, glad you found the article useful.

      Regarding your chain issue, it may be worth removing a couple of links to see if that helps.

      If you still have problems after this, it might be worth buying a Lekkie Bling from Luna Cycles or PreciAlps. These chainrings can improve the chainline and reduce the chance of the chain coming off.

      All the best,
      Tony

      Reply
  • July 21, 2019 at 7:00 pm
    Permalink

    Hello Tony, your articles have really helped me and raised some questions.
    I have a Cube Stereo 2010.
    My bottom bracket appears to be 76mm wide with a hollow tech II threaded bb.
    I was looking at a bbs02b kit but worry I’m going to have problems. I know I’ll have to fit a 36t chainring which is the same as my large crank currently, but I’m struggling to work out if things will fit in the motor/crank arm area. Does the bbs02b kit come with a wider bb option like the bbshd?
    Thanks
    Kev

    Reply
    • July 21, 2019 at 10:03 pm
      Permalink

      Hi Kevin,

      I have just checked the spec on the 2010 Cube Stereo and it does appear to have a standard threaded Hollowtech II BB, with Shimano XT groupset. The bottom bracket shell should be 73mm wide, so the standard BBS02 should fit.

      I have converted quite a few full suspension mountain bikes with either Hollowtech II or SRAM GPX BB’s and never had any major issues apart from the chainline offset caused by the motor can impair shifting to the lowest gear on the cassette.

      With a 73mm BB there should be ample thread left on the motor shaft to fully tighten the inner lockring, but sometimes there is not enough thread left to fully tighten the outer lockring.

      The only other issues I have come across on occasion is the motor lockring may need to be periodically tightened, and you may find fitting the battery to be a tight squeeze or the holes on the battery mounting plate will not align with the bottle cage bosses.

      I hope this information helps.

      All the best,
      Tony

      Reply
      • July 22, 2019 at 5:13 pm
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        Thanks for the advice Tony.

        Reply

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