Electric Bike Conversion Kit Review – 8FUN / BAFANG 250 watt Mid Drive installation

Susan’s success installing a BAFANG electric bike conversion kit and turning her Nihola Family trike into a true car replacement.

 

 

 

 

 

For over a year now Susan has pedaled her Nihola Family tadpol styled trike as her only source of transport before installing a 8FUN / BAFANG 250 watt mid drive electric bike conversion kit recently.  You too will find her process of aid in what ever bike you wish to install a 8FUN / BAFANG 250 watt mid mount electric motor.

Susan readily states that she couldn’t have gone carless without her Nihola Family cargo bike.  But when she bought it she only had two small children who both fitted in the front cargo area; the only problem was that the family enlarged over the next year.  With her third small child came more weight and more shopping.  The need to electrify was evident, but really the question was: which electric kit did she need?  What could she legally do?  What would work with her bike?

 

 

Deciding on which style of conversion

Front wheel hub motors

Front hub motors are simple technology (generally) that provide a cost effective solution.  Front wheel hubs tend to spin easily from pulling the weight of the bike and rider.

In a trike the most relevant example is the Bakfiets.nl electric trike which comes with not one, but two 180watt motors (one in each of the front wheels)  bringing the total power to 360watts which ironically is still under the 250 watt European specifications!  But converting two wheel hubs is just messy – especially with a Nihola Family!  Therefore front hubs were out.

Rear wheel hub motors

The bike being factory fitted with a Shimano Nexus 8 internal hub (like most nicer city focused bikes) meant that most rear hub motors were a problem.  I would not only have to fit a new rear wheel, but also a rear derailleur: Rear hub motors come with generally a 7-9 speed rear cassette meaning derailleur and gear leaver issues.

Therefore if she chose anything in this category, it would be a BionX (with a 9 speed cassette fitted).  But the thought of adding a derailleur, changing the gear leaver or sacrificing one gear all seemed problematic.  So if a mid drive could be found then that would be the next option.

Mid Mount Motors

When I think of mid mounts, I think of fantastic products such as Bosch, Yamaha, Shimano Steps and Impulse: but with all of them the frame has to be custom built.

That left Susan with what I call the ‘Strap on motor’ sub category.  A lot in this category were little better than home jobs not long ago with custom parts and a motor driving the inner chain ring of a dual or triple chain ring setup via a separate chain on your pedal crank.  This always struck me as messy and I simply didn’t want to go that road (despite the fact I only had a single chain ring and didn’t want to add a double and loose my chain guard.

Therefore I settled on the 8FUN / BAFANG 250 watt mid mount motor with a 15ah battery.  Yes, I had to loose the pedal cranks, chain ring, chain guard and effectively the entire bottom bracket setup (save only my pedals).  But it was really the least intrusive system I could find.  But on a cargo bike the large 15ah battery was important (10ah is industry standard) as cargo bikes suck power to cart the goods.

Fitting the handlebar attachments

Removing all the grips, gear leavers, bells and break cables, disconnecting the back break and gear cables from the back wheel (in this case).  Allan keys and screw drivers are all that is needed.

Slide on the computer mounts from both sides.  Next I slid on the nice little bell onto the right hand from where it used to be on the left.  Next I had to remove the old right hand break due to my desire to fit the replacement one from the kit as it has a break sensor that kills the motor the moment you pull on the breaks.

While in a normal conversion I would have done the same on the left hand break lever, the Nihola family has a park break fitting that needed to stay – so it did returning the left hand break lever to its spot after sliding on the thumb trottle on the left side first.

Sliding on the Nexus 8 twist grip controller next on the right I added the grips and tightened everything up where I wanted it.  Next I fixed the computer in the centre and proceeded with the motor.

 

Fitting the BAFANG 250 watt mid drive motor

NB.  You will need a tool equivilent to either a Park Tool BBT-22 or BBT-32 to remove the Nihola Family’s factory standard installation.

The BAFANG  250 watt mid mount is an entire bottom bracket system with a built in motor and chain ring.  Take out the old bottom braket and slide in the BAFANG and your new motor and chain ring hang there as one neat integrated system which wasn’t that hard to do.  Next screw in a mounting plate on one side with an allan key.

Then came the problem: the next nut is non industry standard and nothing fits it!  Yes the supplied bottom braket nut comes with fittings that resemble a BMX 4 toothed tool but it is different!  In the end I struggled with using a Park Tool HCW-5 (not meant for the task) and a trusty set of Vise-Grips.  After this it was simple enough to mount the next bottom braket nut/cup with a standard 16 toothed bottom bracket tool like the Park Tool BBT-9.

Next I mounted pedal cranks and fitted the pedals.  Now came my next headach: the chain ring was bigger than the old one.  So you think: “The problem is?!?”.  But having an internal gear setup without a tensioner such as with an Shimano Alfine system, there was no slack in the chain.  So NOT counting the chain links I angle ground of the chain (as the fitted KMC chain was wider than my Park Tool chain breaker would accept).  Next I just fitted a new 1/8 single speed chain with a standard of 96 links like on a fixie or freewheel bike.  But low and behold with a bigger chain ring (you must have the factory customised chain ring due to the nature of the mounting) this was not enough.  I needed 98 links: yes I broke a whole new chain for the sake of an extra master link and one extra inside link.

Now with the chain tensioned, wheel nuts tightened, rear breaks adjusted, gear cable fixed and the BAFANG 250watt mid motor / drive mounted, it was looking like I was over the hump!  But no.

Fixing the magnet to the back wheel and cable tieing the sensor to the frame I next drilled a hole through the perspex to mount the extra large battery pack to the floor of the front cargo section (as it wouldn’t mount anywere else).

Having fixed the battery I then went to plug in the battery to motor main power leads: but the factory had fitted 3 female connections with just one male connector and some things just were never designed to be connected that weren’t ment to be.  With soldering iron in hand I removed the connections, stripped the cable back a bit, slid over some heat shrink and proceeded to hard wire the connections failing a matching spare male connector.  We all know that the Chinese don’t have good quality control.

 

Test riding the BAFANG 250watt mid mount electric motor conversion kit.

Next I made all the remaining plug in electrical connections and any remaining cable connections.  In this case one of the break sensor connections has been left to dangle covered in black electricians tape as I am down one break sensor – but not a problem.  Fixing all the cables with cable ties the job was now done.

Before I say anything else the reader must note than unlike front hub motors, the gear you are in DOES matter!  In like manner don’t just think you can change gears whenever you like as even a light rotation of the pedals will tell the sensor to apply power so I found I actually needed to back pedal a little with each gear change.

The thumb trottle seems to be more powerful than the pedal sensors which after having ridden scores of eBikes I found quite unusual and unsettleing as you resort to keeping a figure on that thumb throttle when travelling any distance (which is slowly fatigueing).

Where Susan used to travel at 15km/h and struggle due to load, wind and light hills, now she can do a steady 25-35km/h.  Although do not even think about these speeds on a regular trike!  As the fantastically stable (for a trike) Nihola Family is at it’s limits needing ideal circumstance to hold 30-35km/h.

Please note that these speeds are acheived primarily due to heavy pedaling in ideal conditions due to the increased top speeds from a change in gear rations from a new chain ring.  On this bike you can plan a steady 15-25km/h without doing your knees in!

Other than that the conversion kit worked fine despite the many set backs I suffered leading the conversion to take all day.  But under favourable circumstances and with the information above you should be able to install this setup in the same bike within 3 hours.

 

BAFANG 250 watt Mid Mount Review & Conclusion

As to my conclusion on the 8FUN / BAFANG 250 watt mid drive electric bike conversion kit?  Well the quality is low but acceptable and it does the job on a budget offering value for money – but whatever you do, don’t pay full price.  The product doesn’t come with an instruction set either.  If you can use another product do.  If you can afford another product do.  Other than that it doesn the job and is a suitable product for most conversions.