Bafang BBS01 250w Review

In this Bafang BBS01 250w review, I will be going over the pros and cons of this tried and tested mid-drive conversion kit – this is the only variant I can recommend for road legal use in the UK,  EU and Australia. I will be reviewing the more powerful variants later.

Bafang are currently the global leader in plug and play mid-drive electric bike conversion kits, and have been for a number of years. Earlier versions were plagued by reliability issues, and although this can still be an issue, the problem is not as bad as it was a couple of years ago.

I have personally installed over a hundred of these kits on to various bikes, ranging from low-step commuter bikes through to full-suspension mountain bikes.

Bafang bbs01 250w mid drive motor diagram

The main criteria for installation is the size of the bike’s bottom bracket. It needs to be a standard 68mm-73mm wide bottom bracket with an inside diameter of approximately 33.5mm. It must be noted that these kits are not intended to be installed on bikes that use a pressed-fit bottom bracket, as the dimensions are not compatible with the motor unit. There can be a way around this if a special shim and mounting plate are machined by a professional engineer.

If your bike has an eccentric bottom bracket as fitted to tandems and bike’s with internally geared hubs like the Shimano Nexus, installation is still possible, but may be problematic.

The motor comes as a kit with the following key components:

  • The motor unit with integrated controller
  • LCD Display
  • Wiring loom
  • Inner and outer lock-nuts
  • Chainring
  • Chainguard (BBS01 and BBS02)
  • Thumb throttle – I do not recommend fitting this, as it is unnecessary and will increase the risk of controller failure if used inappropriately.
  • 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 bbs01 250w mid drive electric bike conversion kit

Legal information

Please read my separate article on electric bike law here.

Installation

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  This also covers the BBS01 which is physically the same.  The installation will need to be carried out by someone who is fairly competent. Removing the bottom bracket can be a right pain, and you will require a lot of patience!

Technical Data

These motors have an internal cadence sensor, and give assist based on pedalling cadence. The controller will reduce the power in any given power level based on pedalling rpm. This is called the keep current, and depending on the way your particular controller is programmed, this can reduce the power by up to 60%. The logic behind this is the higher the cadence, the less help you need, this is somewhat counter-intuitive as electric motors works best when spinning at a high rpm.

One great thing about these motors, is they can be programmed with a Bafang programming lead and software (which you can download for free here). I will be writing a separate post about programming the Bafang. PLEASE NOTE: Reprogramming the 250w motor to any higher than 15A and 15.5mph (25km/h) will make it illegal for road use.bafang bbs01 250w mid drive motor diagram

The motor itself works through a series of gears, and drives the rear wheel directly through a single front chainring. The benefit of this is the motor is using the bike’s gear ratios for maximum efficiency and torque. The downside of this is you have to make sure you are in the right gear when hill climbing as excess load on the motor can cause controller failure.

The 250w motor is very quiet and smooth, and you have up to 9 levels of pedal assist to choose from.

Reliability

I have installed many BBS01B 250w Bafang motors and to date, and I haven’t had any issues reported – these seem to be confined to the more powerful variants. Having said that there are a number of things to consider.

  • Although I haven’t had any issues with the 250w, they can and do occur from time to time.
  • Controller failure is rare on this model nowadays, especially since Bafang upgraded the MOSFET’s in the controller.
  • You will need a Bafang lock-nut spanner – these motors do sometimes need to be re-tightened periodically.
  • 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 unreliable – I find the black and white C965 display to be the best, I have had several issues with the colour display.
  • Increased wear and tear on the bike chain and gear components – this can be mitigated by fitting a Bafang gearshift sensor.

Riding a Bafang powered Electric Bike

bafang bbs01 250w mid drive electric motor kit installed on a mountain bike

The 250w motor is very quiet and smooth, and you have up to 9 levels of pedal assist to choose from, so you really can fine tune the power output to suit your needs. When climbing step hills you will need to make sure you are in a low gear (as you would be in a car or on a motorcycle) this is especially important as trying to climb a hill in a high gear will put the motor under excess load and could overheat, causing controller failure.

The pedal assist is responsive, and works well, although on some of the older units, there was always a slight over-run noticeable when pedalling stopped. This was down to one of the controller programming parameters being set too high. I always reprogrammed the unit to stop this issue.

The main downside, in my opinion is the extra pedalling resistance this motor has when the power is on ‘0’ or the motor is switched off altogether. It is not too bad on the flat, but it is really noticeable when going up a slight gradient. This is the main reason, I tend to prefer small geared hub motors.

If your bike has a double or triple front chainset, then you will be sacrificing that for a single steel chainring. Bafang only offer a 44t, 46t and 48t option. This in my opinion is high gearing, especially if you are climbing lots of steep hills. There are however aftermarket chainrings available.

If you want to fit the brake levers with cut-off sensors, then bare in mind these are only suitable for cable operated brakes. If your bike has hydraulic brakes, you may want to purchase hydraulic brake cut off sensors or completely new hydraulic brakes with the sensors already built in.

Conclusion

The Bafang mid drive motor is not for everyone. Installation can be challenging and the motor will need periodic maintenance. It is nonetheless an excellent option, and the end result will be a bike that looks more like a factory produced ebike.

bafang bbshd mid drive motor kit installed on a full suspension mountain bike

For a 250w motor it produces a lot of torque, I have done a side by side hill climb comparison of the Bafang 250w vs a 1000w hub motor and the Bafang out performed the larger, more powerful hub motor. The large direct drive hub motor was only rated at 35nm of torque compared to the Bafang’s 80nm.

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 still one of the best electric bike kits available.

==>>SHOP NOW – Bafang BBS01B 250w – FAST GLOBAL SHIPPING<<==

Bafang BBS01B 250w Mid Drive

8.2

Value for Money

8.0/10

Ease of Installation

6.0/10

Reliability

8.0/10

Efficiency

10.0/10

Performance

9.0/10

Pros

  • Very efficient
  • Excellent performance
  • Fits most bikes
  • Programmable
  • Great for hill climbing

Cons

  • Can be difficult to install for the inexperienced
  • Requires regular maintenance
  • Some potential long term reliability issues
  • Limited choice of Chainrings
  • Harder to pedal when assist is not on

16 thoughts on “Bafang BBS01 250w Review

  • December 30, 2018 at 7:37 pm
    Permalink

    Value for Money

    0.00

    Ease of Installation

    0.00

    Reliability

    0.00

    Efficiency

    8.50

    Performance

    0.00

    Brilliant website! The world needs more people like this before we totally ruin the planet…. Keep it up, much respect!

    Reply
  • December 31, 2018 at 12:22 am
    Permalink

    Hi Ken,

    Thanks for the great comment!

    E-bikes are definitely going to increase in popularity. We just need more investment in cycling infrastructure in this country.

    Have a great 2019!

    All the best,
    Tony

    Reply
    • January 3, 2019 at 3:31 pm
      Permalink

      Value for Money

      10.00

      Ease of Installation

      10.00

      Reliability

      9.50

      Efficiency

      10.00

      Performance

      9.50

      Tony converted my giant ATX mountain bike to an e-bike. On Tony’s advice I opted for the bafang BBS01 250w motor, I use my motor as assist only as I still wanted to do most of the work. Tony did a neat and tidy job, the motor has been brilliant with no problems, I enjoy my bike rides more now, as I go out in all conditions. Tony is a trustworthy person, if I have any problems I know he is only a phone call away. I travelled a round trip of 840 miles in 20 hours for Tony to do the installation – Sunderland to Cornwall. I have no regrets and the bike is brilliant. Many thanks Tony, keith.

      Reply
      • January 3, 2019 at 4:00 pm
        Permalink

        Hi Keith,

        Thank you for your positive comments. I hope you continue to enjoy your bike. If you ever need any help or advice, give me a call.

        Cheers,
        Tony

        Reply
  • April 17, 2019 at 6:45 pm
    Permalink

    Hi

    What kind of periodic maintenance could we expect for this motor?

    Reply
    • April 18, 2019 at 9:02 am
      Permalink

      Hi Peter,

      The kind of periodic maintenance required depends on the use the bike would be getting. If you were using the bike for leisurely weekend rides, then I would check everything once a year. If the bike was being used as a daily commuter then it would be recommended to check everything every more regularly (at least once a month).

      The service life of the chain, gear cassette and rear derailleur can be reduced due to the extra power going through the drive-train – This increased wear can be mitigated with the use of a gearshift sensor.

      The motor itself may need tightening (in the bottom bracket) every few hundred miles using a Bafang lockring spanner.

      It is recommended to re-grease the motor internals every 3000 miles, I use Mobilgrease28 which is an aviation-grade grease that can prolong the life of the Bafang motor internals.

      There are other parts of the motor that can wear over time, including bearings and gears, but this seems less of a problem on the BBS01 250w due to the lower power output.

      I have just serviced a BBS01B 350w for a customer who has done in excess of 3000 miles, and all the internal gears were still in excellent condition.

      Out of all the Bafang motors I have installed the 250w has (so far) proven to be very reliable.

      If you have any more questions, please let me know.

      All the best,
      Tony

      Reply
      • May 9, 2019 at 12:57 pm
        Permalink

        please anybody readiing this article, do not get bafang fitted to any bike, at a cost of 850 pounds the unit only lasted 14 months, the bike was looked after and well maintained, save your expence and time and get a branded make of ebike, ie giant cube merida etc, cycle dealers will not touch bafang so you have no means of repair, if it goes wrong the kit is uesless, proper ebiikes have safety in mind, better frames up graded brakes, ebike ready wheels a standard bike may not always cope with added wieght and stress of a motor, please bear that in mind, please read reviews on the net regards problems with bafang, do your homework it is not a reliable kit.

        Reply
        • May 9, 2019 at 8:08 pm
          Permalink

          Out of the 30+ Bafang 250w BBS01’s I have installed in the last three years, this is the first one to pack up – albeit after 14 months and a couple of thousand miles of use. I understand your disappointment and frustration as I know how much you liked the bike, but you have to realise that no electric bike motor is perfect – even Bosch motors pack up occasionally. I had a customer who spent nearly £5k on a Specialized Levo Comp Carbon and he is on his second Brose motor after only a couple of hundred miles!

          You are correct about the lack of Bafang technicians in the UK – they are very few and far between. You’re also right about the fact that most bicycle dealers won’t touch a Bafang or Tonsheng motor with a barge pole as they are trained only to deal with the likes of Bosch, Yamaha and Brose motors.

          Bafang motors are easier to repair than Bosch motors, and there are plenty of parts available, unfortunately you need the time and mechanical know-how to repair them.

          In a previous post I discussed the pros and cons of converting a bike vs buying a ready made ebike and I agree that buying a factory produced electric bike is the best option for most people. I know a lot more now than I did a year and a half ago, and I now only recommend electric bike conversions to people who are local to me or people who have the mechanical knowledge to replace parts if they go wrong.

          A lot of the reliability issues reported on forums with Bafang motors are limited to the more powerful BBS02 750w, the early model had poor quality controller MOSFET’s and this caused thousands of units to fail (back in 2014-2015).

          I sincerely hope you enjoy your new bike and i’m sorry this one let you down so badly. It’s a shame the company up the road from you that are supposed to be Bafang dealers weren’t interested in trying to help you out.

          All the best,
          Tony

          Reply
  • May 15, 2019 at 12:22 am
    Permalink

    Hi Tony
    May I ask how much length is the bottom bracket of the full suspension B’twin in your last picture? I am thinking to put a Tongsheng TSDZ2 on it. I guess it should be 73mm square taper.

    Cheers
    Alex

    Reply
    • May 15, 2019 at 6:24 am
      Permalink

      Hi Alex,

      Yes, that’s correct, the B’TWIN Rockrider 540s has a standard 68-73mm square-tapered bottom bracket. The Bafang mid-drive fitted perfectly, so the TSDZ2 should also be a perfect fit.

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

      All the best,
      Tony

      Reply
      • May 16, 2019 at 2:03 pm
        Permalink

        Value for Money

        10.00

        Ease of Installation

        10.00

        Reliability

        9.00

        Efficiency

        10.00

        Performance

        8.90

        Can you tell me if you could fit without problems the battery on the frame of Btwin 540s (because of the back suspension i’m worried battery won’t fit), and i heard 540s have 100mm bottom bracket, are you sure btwin 540s is ok for Bafang 68-73mm bottom bracket? Thanks a lot 🙂

        Reply
        • May 16, 2019 at 7:22 pm
          Permalink

          The Hailong Shark case battery (360mm x 90mm x 90mm) was difficult to fit. I converted two 540s bikes last year and the XL frame was tight and the L frame was very difficult. In order to get the battery to fit, I needed to remove the forward rear suspension mounting bolt and push the shock upwards. Another thing to consider is the 540s does not have any bottle holder holes. I had to drill two holes in the frame and use riv-nuts.

          The 540s in the photos definitely had a 68-73mm square-tapered BB. Apart from problems fitting the battery the Bafang motor fitted perfectly.

          If you have any more questions, please let me know.

          All the best,
          Tony

          Reply
          • May 17, 2019 at 10:24 am
            Permalink

            then i’m considering a b’twin 560 but i heard it has some small issues with mounting the bafang motor because of the frame …you know something about that?

            Thanks a lot for your help .

          • May 17, 2019 at 2:00 pm
            Permalink

            I couldn’t say for sure if a Bafang motor would fit the 560s as I have never converted one, but I believe it uses a Shimano Hollowtech II bottom bracket, which means the motor should fit as it would be 68-73mm x 33.5mm (outer diameter).

            If you have a Decathlon store near you, it would be worth seeing if they have one there, and take some vernier calipers to measure the width of the BB and the outer diameter of the bottom bracket.

            Regards,
            Tony

    • May 18, 2019 at 9:18 am
      Permalink

      I’ve just checked the photo and it is definitely a Hollowtech II type threaded bottom bracket. The Bafang motor should be a straightforward fit.

      I couldn’t quite see from the photo if it was 68mm or 73mm. If it’s 73mm you will need some spacers and longer bolts between the mounting plate and motor – I usually use a couple of 10mm nuts.

      Let me know if you need any more info.

      Reply

Leave a Reply

Your email address will not be published. Required fields are marked *