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It’s time for a battle of the two best-selling mid-drive e-bike conversion kits from Bafang. In this comparison between the Bafang BBS02 vs BBSHD, we take a closer look at the motors to see if it’s worth forking out the extra money for the BBSHD. The information shared in this article is based on the author’s experience installing both of these Bafang conversion kits over several years.
What’s the Difference Between the BBS02 and BBSHD?
The BBS02 was first released in 2014, and at the time was one of the first plug-and-play mid-drive electric bike kits available. Unfortunately the ‘A’ version suffered from poor quality controller MOSFETs that could not deal with the higher current of the motor, and were very susceptible to overheating leading to a lot of premature failures.
In 2015 Bafang upgraded the controller from six to nine generic MOSFETs to give it the ability to handle 50% more current, but unfortunately, they still generated a lot of heat.
In 2016 the ‘B’ version was released. This (supposedly) had a better controller with higher quality ‘branded’ IRFB3077 FETs, which convert more of the input watts into power, and less of the input watts into waste heat.
The Bafang BBSHD was introduced in 2016, and the main difference between the two motors is the HD is physically bigger and has external cooling fins (to help with heat dissipation). The Stator is 66% larger, and the controller has twelve IRFB3077 FETs and can handle 30A of continuous current. Input voltage remains the same as for the BBS02.
What this translates to is the BBSHD will produce more torque, have better heat dissipation (and reliability?) and produce more peak power.
Bafang BBS02 vs BBSHD Power Comparison
| Bafang Model | Battery | Peak Power (Watts) |
|---|---|---|
| BBS02 500w 36v | 36v (42.2v x 25A) | 1055w |
| BBS02 500w 48v | 48v (54.4v x 18A) | 864w |
| BBS02 500w 52v | 52v (58.8v x 18A) | 1058w |
| BBS02 750w 48v | 48v (54.4v x 25A) | 1200w |
| BBS02 750w 52v | 52v (58.8v x 25A) | 1470w |
| Bafang Motor | Battery | Peak Power |
|---|---|---|
| BBSHD | 48v (54.4v) x 30A | 1632w |
| BBSHD | 52v (58.8v) x 30A | 1764w |
As you can see from the table above there is only 294 watts difference between the BBS02 750w and BBSHD (if a 52v battery is used) – the big difference in the feel of the HD is the amount of torque it produces. This is up to 160N.m against 120N.m for the 750w. The bigger motor spins faster – 130-150 rpm (120 rpm for the 750w) and has a reduction ratio of 1:21.9
Put simply the BBSHD is more robust than the BBS02, produces more power, but most importantly more torque and much better heat dissipation. Incidentally the ‘HD’ stands for ‘heavy duty’. The HD is also nearly 1kg heavier than the 02, and physically slightly larger.
BBS02 or BBSHD – Which is More Reliable?
I have installed over a hundred Bafang mid-drive motors in the last 5 years. The BBS02B accounts for around 60 units and the BBSHD around 25 units.
I have had long-term reliability issues with both motors, but the BBS02 is more prone to controller failure (I have a box of knackered controllers in my workshop to prove it!)
It seems that there is a correlation between controller failure and battery voltage (plus the way the bike is ridden). I have never had a controller fail on a bike running a 48v battery, but have had over 10 failures on the BBS02 and maybe 3 or 4 on the BBSHD. That is a failure rate of 17% for the 750w and 12% for the HD, which in my opinion is unacceptably high. I know that one of the BBSHD failures was down to a faulty battery BMS, and another was being used daily in very testing conditions.
48v or 52v Battery?
Both controllers have a maximum operating voltage of around 60v. This leaves little margin for error when using a 52v battery. 52v batteries fully charged will produce 58.8v, but I have tested some with a multi-meter and seen over 59v on occasion. A 48v battery will produce 54.4v fresh off the charger – this leaves a reasonable buffer zone.
I prefer a 52v battery. Having the higher start voltage is advantageous as it means the motor will be producing optimum power for longer versus the 48v battery. Another benefit is the same power can be achieved with a slightly lower current, reducing heat build-up.
I covered nearly 2000 miles on a 52v BBS02 powered bike for a year, without even a hint of a problem, but I only used the bike as pedal assist and very rarely went beyond power level 3. I also have a lot of happy customers whose bikes are still running fine after a year, even though a 52v battery was used.
One thing I did start doing on the 750w was limiting the current setting in the firmware to 18 or 20 Amps. After I started doing this controller failure ceased to be a problem. Having the more powerful battery on a BBSHD seems to be less of an issue.
Should I use a Throttle?
The problem I see with the Bafang throttle is that it acts like an on/off switch. There doesn’t seem to be good power modulation. I have altered the firmware settings for the throttle with some success (specifically the start current). But the fact remains, I have no control over how customers use these throttles, and if you are going up a steep hill in full power mode, and you are in the wrong gear, you will be subjecting the motor to unnecessary load – causing rapid heat build-up.
The BBSHD is much less susceptible to the above problem, and can take a lot of abuse (but it still has its limits).
Which One do I Choose – BBS02 or BBSHD?
This depends on your budget and intended use. If you want an off-road electric bike that you can hammer the hell out of, then I would say go for the BBSHD. The extra £175 price may seem a little excessive, but the HD is just a more robust, more powerful and more efficient motor than its smaller sibling.
If you are going to be doing some mild cross-country-type riding and are not going to be using the throttle or tackling any ridiculously steep climbs then the BBS02 may be more suited to your needs.
As far as battery choice is concerned, I would err on the side of caution and stick with a 48v, but if you do want the benefits of the 52v, then I would limit the max current setting in the firmware to 18-20 Amps, just to be on the safe side.
Conclusion
Both the Bafang BBS02 and BBSHD are amongst the best e-bike conversion kits available. And, they will transform any bike you install them on. But before you part with your hard-earned cash, it is important to remember these motors aren’t perfect and like any electrical item, are prone to problems from time to time.
I always advise customers that you need to be a bit of a DIY enthusiast to run and maintain a Bafang mid-drive. Ultimately, if you treat the motor with a little respect, be very careful with your gear selection (especially when climbing hills or hill starts), and don’t constantly ride in full power mode, then you should be fine.
If you are going to treat your conversion like an off-road electric motorcycle, then it would be worth steering clear of the BBS02 and going for the BBSHD, most suppliers will replace a controller at least once under warranty, but after that, you are on your own. And at over £100 a time, it can become an expensive habit!
Buy the Bafang BBS02B 750w
Buy the Bafang BBSHD
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Thanks for reading. If you have any questions please feel free to leave a comment below.
Thank you very much for sharing your knowledge. I was intrigued by your comments: “There doesn’t seem to be good power modulation. I have altered the firmware settings for the throttle with some success (specifically the start current)” . Would you mind sharing how you have done this as I would like to replicate what you have done. I have the BBSHD with a 52V battery — don’t have big hills and basically want reliability more than anything else — for commuting so that I can get to work without sweating.
The settings I usually use on a BBSHD throttle are as follows: Start voltage 11 (1.1v), End voltage 42 (4.2v), Mode: Current, Start current 5, Speed limit: 40km/h, Designated assist is up to you but I usually set it to 9. This is about as smooth as you can get it. If you want to conserve battery power you can cap the peak current off at 18 or 20A (30A as standard). When I used a BBSHD power MTB as a daily ride, I very rarely went about level 2 or 3 unless I was riding off-road. For more info, check out the article on electricbike-blog.com
Cheers,
Tony
Hi Tony, thanks for the advice you have been offering people you are doing a great job please keep it up.
I have just purchased a Bafang 750w mid drive kit with a 48v 17amp battery I installed the kit and I can see the bike is going too fast and the motor temperature becoming too hot after 10 miles of flat road non hilly riding so I used the programming cable to reduce the 25 Amps that was set by the manufacturer to 22 Amps and reduced the start current from 50 to 30%, kindly advice if this setting is safe for my controller. Thanks
Hi Jim,
Yes, that is safe. I usually reduce maximum current down to 18A and start current down as low as 5 or 10%. I think Karl on electricbike-blog recommends 15%. Even at 18A the motor will be producing 864w peak power which is plenty, plus it will run a lot cooler. Setting the start current low is also better for controller longevity, although you don’t get that initial surge of power when you start pedalling and the power comes on much smoother.
Glad you’ve found the blog useful, if you have any more questions, let me know.
All the best,
Tony
Thank you for your advice.
You’re welcome?
Fitted the 48V 750 BBS02 motor to my trek hybrid a couple of months ago with a 48V 17.5Ah battery pack and P850 controller but only as pedal assist with 9 assist levels.
I was a little hesitant at first spending £750 but what a difference its made to my riding enjoyment. Being 61 with a dodgy knee, uphill sections were hurting but now they are a breeze.
I haven’t noticed any heat issues but your riding preference appears similar to mine so might take your advice and lower the current settings. I rarely use it above level 5 and mainly on level 1 to give the legs a working and so far battery consumption has been excellent, often doing 40-50 miles with only 20% consumption.
Anyone humming & harring as to whether to get one, I would definitely say go for it, way cheaper than a dedicated e bike and much easier to get hold of at present. No point abandoning a good bike or selling it off cheap.
Hi Paul,
Thanks for sharing. Glad you’re enjoying the BBS02 – it’s definitely worth lowering the current if you’re not going above 5. You’ll also find you can fine-tune the assist even more.
All the best,
Tony
Hallo, ich suche verzweifelt nach einem Mittelmotor mit Rücktritt. Könnt ihr mir da weiter helfen?
Gibt es so einen von bafang?
Lg Steffen
Hallo Steffan,
Leider ist diese Funktion beim Bafang nicht verfügbar. Sie benötigen einen Tongsheng TSDZ2 mit Rücktrittbremsfunktion. Hier ist der Link zu dem Motor, den Sie bei eBay benötigen:https://www.ebay.de/itm/255155586846?hash=item3b6875471e:g:boIAAOSwuQBdAgIP
Grüße,
Toni
Hi Tony,
This is an excellent website, I have really picked up lots of information that will help with my bike build, thank you.
Can you recommend a supplier in the UK for the BBS02B? I have seen plenty on ebay and amazon but I’m a bit concerned about after sales service with either of those. I also came across custombuilt e bikes who are a little dearer but are in the UK and have good reviews, do you have any experience of them or anyone else? I was hoping to find a link from your website but I couldn’t, although I could have missed it?
Thanks again,
Dan.
Hi Dan,
Eclipse Bikes have a good reputation, I’ve brought a few kits off them over the years without any issues. Custom built e-bikes in Exeter are quite a new company but they seem to know their stuff and early reports suggest they offer good after sales service. It might also be worth trying Francis at Electron cycles – he knows Bafang motors inside out and even custom-builds controllers.
All the best,
Tony
Hi David
I have a Trek DS2 2019 and a UK hilly town ride. At age 71 it’s becoming a bit harder and conversion seems to be the way to go but I am having trouble with my due diligence. I can’t find any references to this bike or it’s crank mounting size. Without taking the bike apart and measuring accurately, the best I can come up with is about 90mm. I had been going to go for the Bafang BBS01B 36v 250w with a small (?) 10amp battery ie. pedal assist with the minimum of weight and range. Is the BBSHD my only option or should I be considering a hub drive please?
Hi John,
The 2019 Trek DS2 uses a standard 68mm-73mm threaded bottom bracket so you will be fine with a BBS01B. A 10Ah battery should give you a potential range of 25-35 miles depending on how much assist you use.
Regards,
Tony
Are you sure Tony? As mentioned above my BB seems to be a approx. 90mm across. And I have since come across some other info. This website mentions a sealed cartridge
https://www.leisurelakesbikes.com/bikes/hybrid-bikes/trek-dual-sport-2-hybrid-bike-2019-trek-black__310210
And another that ‘BB95 (MTB) ………… ): Exclusively used by Trek as an integrated bottom bracket standard, BB90/95-specific bearings press directly into the frame’
https://www.empoweredcycles.com/blogs/news/101474694-bottom-bracket-standards-and-bafang-mid-drive-motors
This suggests I might need to do a forlorn search for an adaptor
Looking at the photographs and the model / year manufacture I would be very surprised if it’s anything but a 68mm-73mm BB. Most sealed cartridge bearings are 68mm (road / hybrid) 73mm (MTB) or 100mm-120mm (fat bike). Trek specify a sealed cartridge bearing and the type of crankset fitted would indicate a standard threaded BB. Are you taking the measurement across the bottom bracket shell (underside of bike frame). I would advise removing the bottom bracket to be on the safe side – the size will be on the bearing.
So they are the same power 48v 30a but the bbshd has better efficiency.
The BBS02B is 25A and the BBSHD 30A – the BBSHD controller has more MOSFETS and they’re of higher quality.
Hi,
I have a Van Raam bike that I use with my disabled daughter could someone recommend what Bafang mid crank power I should use? the use is mainly to help me up hills.
Hi Lilian,
I’ve had a look on the Van Raam website and it looks like the Bafang mid-drive might be compatible with some models, but I couldn’t find the bottom bracket specification to be certain. As far as power is concerned, if you were using the bike on UK public cycleways it would need to be the 250w model and speed would have to be limited to 15.5mph. The more powerful variants would be more suited to your needs, but once you go over 250w of continuous power the bike becomes subject to the same laws as a moped. A rear wheel hub motor may also be an option. Let me know what model you have and I’ll do a bit of research.
Regards,
Tony
Hi Tony,
I would like to install a BBSHD on a fat bike Specialized Fat boy 2016. The Bottom Bracket is the PF30 100mm, but cannot find any adaptor PF30 to BSA of 100mm. The link you suggest is up to 92mm if I am not wrong. Any idea where to buy it? Any workaround?
Regards,
Fabio
Hi Fabio,
I’ve checked some of my regular suppliers and they only do a 68mm or 73mm PF30 to BSA threaded adaptor. I also had a look on Aliexpress but couldn’t find one there either. I think the best solution would be to purchase a regular sized adaptor like this one and take it to an engineer to see if he can insert a section to widen it to 100mm.
Regards,
Tony
Pls. be careful with this solution. You may not be able to fit the motor inside… I took another approach and printed my adapter on a 3d printer. The plastic does a good job, but I had to produce a second version with the inside hole offset to the side from the center to be able to fit the motor inside. Something I didn’t think see at first…
I have a 60V battery 20amh and I have a 48V 1000 BBSHD. Can I use this battery for my bafang?
No, you wouldn’t be able to use a 60v battery as when fully charged it will exceed the BBSHD’s maximum controller voltage capacity. A 60v battery fully charged is around 67.2v a 48v or 52v battery would be fine. I think Luna Cycle do an uprated controller that can handle up to 72v (for the BBSHD).
I need to buy a used bike with mechanical or hydraulic brakes for a bafang kit bbs02. What used bikes would make a good fit with the kit. I am 80 and have 4 replacement joints and ride about 15 mi a day. Maybe I need the had. Thanks for what you do. Duke
Hi Duke,
I’ve converted quite a few Giant Roam hybrid bikes, they’re usually very straightforward. Any decent hybrid should be easy to convert – Trek, Specialized etc. Hybrids are better because they have a more relaxed riding position. Steel touring bikes are also good donors – a Surly Disc Trucker would make an excellent choice – bullet proof frame and suits a Bafang mid-drive perfectly. They usually come fitted with Avid mechanical disc brakes and Shimano XT gearing and wheel hubs.
I hope this helps. If you have any more questions, let me know.
Cheers,
Tony
I ride mostly city, some gravel, and like to go up hills without working too hard. I have a back dissability, which means i need to use my throttle a lot,, or my back seizes up.
My ride is a Townie Electra, and I’ve been using a very innadequate bionx. tried my wifes rear hub 500-750 watt bafang, that’s only a bit better. I like torque for going up hills, and don’t want to overheat on a hill that is let’s say 5 blocks constant.
so, question and concern. On the one hand I have to way out the likelihood of getting stopped by an eager cop who is wattage savvy, apparently they are getting trained a bit on this in Vancouver where I ride. It hasn’t been a point of actually stopping people yet, but it’s in the discussions among the police and their trainers.
So, here are my thoughts, can a guy likely get away with getting a better motor, that isn’t going to overheat, but you would perhaps want to limit to 500 Watt, and maybe that would satisfy a cop. maybe. if I did do that ‘limit’, then which motor would be best suited, a tuned down bdshd, or a bbs02b? I thought maybe because the bdshd is overbuilt, it will last me longer, not overheat, I’m not trying to save money one over the other, i just want performance, and quality.
Hi Kelly,
I have always found the BBS02B 500w 48v to be plenty powerful enough (plus it’s got 500w stamped on the motor) peak power on this motor is 864 watts and it has enough torque to haul a 110kg male up a 15% gradient with relative ease. I used a BBS02 750w for a year and 2000 miles and never had a problem with overheating – an average ride where I live is 100ft of climbing per mile ridden.
I also used a BBSHD on a hardtail MTB for a while and it was totally reliable (it’s still running well 3 years later with the new owner). I loved the BBSHD, but very rarely used full power mode, it’s definitely a bit more efficient than the BBS02 especially when used at lower power levels – I used to get 80-90 mile range out of a 48v 17.5Ah battery using the assist wisely.
The problem is Bafang stamp the power output on their motors so even if you restrict the speed limit and power output at the controller, there’s a chance a cop may confiscate the bike anyway. 250w labels are commonly available in Europe, so you could probably get a 500w one in Canada. I think as long as you ride the bike sensibly and don’t draw attention to yourself, I don’t see any reason why a cop would stop you. I never had any issues here in the UK, but I always kept my speed down, especially in towns.
If you need any more advice, let me know.
Cheers,
Tony
Could you put a 2 in front of the 5 and scrub out the last 0?
Your best bet would be to use some fine sandpaper, then satin black paint and buy one of the Bafang 250w stickers that are available on eBay or Amazon. Or you could buy the 250w BBS01B and increase the current to 18A using the config software and USB lead.