Bakfiets and mid drive - workcycle long with Bafang 8fun

[KnNashua]

I plan to buy a workcycle cargo long (a bakfiet/box bike, wooden box in front of handle for 4 kids.) For the one monster hill that guards the only way out of our neighborhood I plan to add electric assist, and have chosen the mid drive gear Bafang / 8fun BBS02 750W at 48v. I plan to wait until the new 25A BBS02 controllers are available in the next few weeks.

Any concerns about adding a mid drive to a box bike, particularly this cargo bike? Concerns on this particular drive? New to all this.

I'm checking with store that the bracket width is either 68mm (2.68 in.) or 73mm (2.87 in.) wide bottom bracket shell and 35mm inside diameter.

Another concern is with the step through frame (not diamond) the motor goes under, but with this non-offroader and the steering rod so low as well is that really an issue?

Was going to go with with falco hub drive but this bike has drum brakes, no fork mounts for calipers, a nexus 8 shifter in back, an odd fork for 20" in front so can't swap, was going to put in front add magura hydralic rim brake and change out glossy painted rim for machined one. Using a mid drive avoids all that.

Want the power to climb, but plan to pedal and with kids in so won't be cruising high-high speed, so need large e-assist load, but little total amps used over entire ride, so don't need a lot of amp hours on battery. That being said other than preferring space wise a downtube battery, don't know what requirements in battery choice should dictate battery selection other than COST.
Thanks for any input. Anyone done something similar?

 

[Bikengineer]

Haven't done it but motor will be low. Mock it up first to see if you're happy.
Most conversions I've seen replace 20" wheel with a hub motor adding disc brake at same time. That'd require a weld but steel fork is made for it. The next bike I'd like to acquire is the Bullit and of course it'd be electric. Mid drive would be ideal so let me know how you go.
Maybe the motor could be mounted above the (flat) down tube?

 

[buddhak]

Hello,

I am new here and new to e-bikes in general. But I joined because I am contemplating a very similar machine - bakfiet style cargo hauler with some electric assist for take-off and hills. I am tuning in to see where this project goes. Have you considered a 2wd solution? Is that a stupid idea?

EDIT: I see this is posted to the mid-drive sub-forum. My apologies. I found this with the Search function.

 

[KnNashua]

thanks bikerngineer, I'll report back with what I end up going with and how it works out.

@buddhak, no worries about mentioning 2wd as if the midrive can not work for the bike (do to fitting, or clearance) I originally mentioned reverting to hub motor. 2wd would be cool but to make it work one either needs to forget about $, or give up on the cooler systems with torque sensors, regen braking, and actual peddle assist and use two cheaper hubs to come to same price.

I may just put in the 500W version, same motor lower amp from controller, wondering about mid drive affects on nexus 8, and save on batteries as some 48V don't seem to provide what the 750W needs to draw in peak amps, both save $ and maybe lifetime of batteries chosen?.

Speaking of cooler systems components, would think the Bafang is perfect not just best choice if it had a torque sensor to replace the cadence sensor, they keep talking about developing and offering but doesn't seem to be available from them yet. I'll search posts here to see if folks have figured an easy way to add ones own torque sensor. As it is my first go around don't want to delve to deep into complex mods as my opinions are based on reading specs and general understanding how things work in world, this will be my first electric bike, and happily ridden my stock Gary Fisher Marlin for 10 years so no deep bike knowledge either. So feel free to point out where I'm totally off base as glad for the guidance, until I actually make the purchase that is

 

[samsavvas]

may just put in the 500W version, same motor lower amp from controller, wondering about mid drive affects on nexus 8, and save on batteries as some 48V don't seem to provide what the 750W needs to draw in peak amps, both save $ and maybe lifetime of batteries chosen?.

Speaking of cooler systems components, would think the Bafang is perfect not just best choice if it had a torque sensor to replace the cadence sensor, they keep talking about developing and offering but doesn't seem to be available from them yet. I'll search posts here to see if folks have figured an easy way to add ones own torque sensor. As it is my first go around don't want to delve to deep into complex mods as my opinions are based on reading specs and general understanding how things work in world, this will be my first electric bike, and happily ridden my stock Gary Fisher Marlin for 10 years so no deep bike knowledge either. So feel free to point out where I'm totally off base as glad for the guidance, until I actually make the purchase that is

I think the bbsxx will be fine on your bike as long as the BB is ok. If you think about it the long wheel base will actually give you more height over kerbs etc even if you will need to located the motor below the plane of the main tube.

I wouldn't worry about the torque sensor - it seems to be a long way off and the cadence sensor works fine. Remember your going through the bikes gears so you'll naturally be in a lower gear when going uphill or against the wind so you will pedal faster and thus get more power. Torque sensors make sense with a hub motor but I'm struggling to see the same logic or necessity for a mid drive. Lower tech and cheaper is, in this case, absolutely fine I reckon. Best to spend your money on a good battery from Ping or em3ev.

I have several cargo bikes including a Filibus which is getting a bbsxx.

Savvas.

 

[birdseye]

I seem to remember a thread somewhere dealing with putting a bafang onto one of these. The builder had to do some frame modification to get the motor to fit. Nothing major enough to require a frame builder, but the frame had to be dented/deformed an little to make it fit.

The bigger concern for me with these bikes is that, for the weight, the brakes are crap. Drum in the front and coaster (barf) in the back. These Bakfeits are not designed for hills and brake failure going down hill is a concern. Back when Splendid cycles in Portland was making the stoke monkey mid drives, they discouraged putting the drive on these bikes because of that reason. Too much speed and not enough stopping power.

So if you go ahead with this, I'd look into having some disk tabs brazed on to at least the front, if not the back as well. And then upgrade the brakes. Go hydro if you can.

 

[KnNashua]

I e-mailed Sterling with bendelectricbikes.com and asked if the Bafang fit on a Bullit. He said he had been thinking about that and give him a few hours. He e-mailed this photo a couple hours later. Wow.

After contemplating buying a Bullitt for a while that was nixed when making it fit my 5'4" comfortably enough would involve seat and handlebar changes, at min. and frame just doesn't seem to work and its on the opposite coast from us so trying out different setups is hard without double paying for components, then it really doesn't haul kids and cargo as it is smaller, and I mocked up my own box but adding a bench so the kids legs don't take up the rest of the length means the vertical pole puts the headset where it would hit them on the helmet, and don't like the canopies available either, so as cool a cargo bike is, to make it work would cost a lot more and really wouldn't work as well for getting groceries and kids as smaller box, and having to hack ones own way to add a rack taking weight off front wheel, decided too cool, the more mini-van of bikes fits our need - so back to Workcycle Bakfiets Long

OK, I have to admit I wanted the Bullitt, it was the first bike we thought of for this, and to my embarrassment and to show how cool Splendid and Bend EB are, with the dog screaming and the kids barking in the background I accidentally e-mailed Bend about buying the discounted floor Bullitt (Alfine 11, with Shimano Centerloc disc, in Clockwork Orange.) Sterling at Bend Elec. Bikes was nice enough to forward this to Splendid so they instead of he could make a bike sale, and as he has the Bafang could provide just that part. Then we backed out of going the Bullitt route the next morning, all timed so Joel at Splendid could read all the e-mails at once. So point of story, while I might be a time wasting non-customer, Oregon has two great bike shops. (Going to buy the Bafang still from BEB.)

 

[KnNashua]

Update - Bought the Workcycle

Got at BicycleBelle in Somerville. The kids and us love it, went all over Cambridge and Somerville, then around Nashua for errands, then down dirt road bike bath by river. It is a real smooth ride, quality of frame, box and the higher component level compared to other Bakfiets are nice. The handling is great, love the 4 point kickstand with wheel locked, kids climb on on own. only one dislike, simply magnet to hold up kickstand if turned doesn't work, cranked down on to fix.

About the brakes, since we bought the Workcycle version versus a Chinese, a Babbeo, or the stripped down versions of the Bakfiets.nl or Azor Milano (if you can find them they offer high end components on these in europe), it came with M81 drum brakes in front and back. The others come with M41 drum and if you let some of them do the electric assist you get cable rim brakes or buy cheap Chinese get coaster brakes. Workcycles e-assist front hub motor losing the drum gives solution of hydraulic rim, which I find odd versus having frame ready for disc.

Although I like the Alfine 11 and disc brakes on the bullitt, the nexus 8 and higher level drum breaks with cooling both work well on steep long hills so far. In fact the M81 brakes work much better then I imaged, my only real concern now is the Nexus 8, its much better than the Nexus 7 BUT I wish it was a NuVinci as worried about always rolling off power before shifting. Suppose if I screw this up the replacement is a NuVinci. I'll have to see if satisfied long term, but loaded on steep hill has performed admirable as of yet.

What hasn't performed on steep hills with full load is the riders. It has been doable for me, but killer for my wife - so the Bafang will be installed.

 

[samsavvas]

Remember your going through the bikes gears so you'll naturally be in a lower gear when going uphill or against the wind so you will pedal faster and thus get more power. Torque sensors make sense with a hub motor but I'm struggling to see the same logic or necessity for a mid drive.

After waiting a week or so for my brain cells to catch up I have realised that what I wrote above is not accurate. That is, with the BBSxx cadence sensor, you do not get 'more power' with a higher cadence. With the cadence sensor the motor is essentially on or off. You do go faster at higher cadences but that's because you are pedalling faster! Your can get more power (that is, more assistance) by adjusting the PaS level you are on.

So a torque sensor BBSxx would in theory work more 'naturally' than the current cadence sensor on hills or if you jump out of the saddle to accelerate. Functionally though I think the cadence sensor works fine. You just need to maybe use the hand control to set the appropriate assistance level when faced with a hill. No one seems to know how far away the torque sensor version is although Paul at em3ev has mentioned it a couple of times ( and I'm sure he'd know if it was close to release). Apologies for the brain dysfunction!

Savvas

 

[Samd]

I've ran a large bakfiets with a rear geared hub at 1.2kW for a couple of years, and I currently have a BBS02 on my wife's Yuba longtail bike.

Whilst the cult of the mid drive continues, they are ok, but unless you are up extreme hills then a rear geared hub with plenty of amps on tap is fine too.

 

[KnNashua]

@samd

Your mentioning Rear geared hub prompts me to ask why rear not front hub? The Bakfietsen put weight on front unlike long tail, and with most of the European versions they come with internal gear train that would have to be swapped out and lossing covered chain, and the now the brakes too (although same for front.). 20" front wheel too. If one was to not use a mid drive but a hub why the back on a bakfiets not the front? (I have a few guesses.)

 

[BikeFanatic]

HI, welcome to the Ebike community, you are going to have alot of fun with that bike.

Thought you might find this blog helpful, a local guy who converted a bakefit type bike to Ebike mid drive with a stokemonkey.

Do you live around boston or nashua? If you are not able to make the Bafang work I have a couple of extra
hub motors here that I would sell very cheap if someone was local. NO front motors though.

http://bostonbiking.blogspot.com/2013/12/stokemonkey-kit-installation-classic.html

 

[Samd]

No the front is fine - Ira Cox is on here and on instagram and runs a nice front hub. I tend towards backs as I stock more of them that are large. No reason why a front can't be made to deliver a lot of torque through a well supported fork.

There are a bunch of other cargo bike threads on here- worth searching.

 

[tfahrner]

The bigger concern for me with these bikes is that, for the weight, the brakes are crap. Drum in the front and coaster (barf) in the back. These Bakfeits are not designed for hills and brake failure going down hill is a concern. Back when Splendid cycles in Portland was making the stoke monkey mid drives, they discouraged putting the drive on these bikes because of that reason. Too much speed and not enough stopping power.

Splendid Cycles has never made nor sold Stokemonkey, nor the Bakfiets.nl Cargobike that most people just call a bakfiets. You are thinking Clever Cycles. Splendid opened a few years after Clever Cycles, a few hundred yards away with a similar name, similar colors and furnishings, and similar products, such as the Bullitt. Splendid are good people, but this confusion comes up over and over. I am one of the founder/owners of Clever, so I admit a peeve.

The bakfietsen that we've imported to Portland have never had coaster brakes. It is true that the 1.0 version of the product imported from 2007-2009 came with low-level versions of Shimano Roller brakes (IM-40-50), that were not good enough for hills requiring high-torque assist. That's why we didn't and don't recommend assist for these older versions. Newer imports, at least by us, have all had much better brakes (IM-70 and IM-80), but then other things changed that made it not work so well with Stokemonkey as designed, so we never promoted the pairing.

Also (excuse my pedantics), there is no such thing as a bakfiet. Bakfiets, ending with an S, is the singular form. Bakfietsen is the plural form. It's pronounced BAHK-feets.

 

[KnNashua]

Wondered when someone would point out the missing s. Started post at beginning of process, much learned so far (thanks for posts above contributing to that.)

The box bike has hauled a lot of stuff and kids all over, up and down some big hills too but they are too much for my wife and fully loaded a big hill is pretty killer on me (not used to biking, job involves lifting big things all day but no cardio.)

@samsavvas glad you wrote again, first post was convincing me that their was two separate variables for amount of power, the second post gives me a firmer grasp of what the controller does with input.

@bikefanatic, cool blog, recognize places in the photos. Moved to Nashua from Somerville, but if not commute time it is only 40 min. So weekends, or quick mid-day, or come down mid-day and stay late, anything to avoid car traffic heading out of city. Still planning on the mid-drive route.

@tfahrnr - jealous of the plethora of Portland's bike stores including yours. We have two here in Nashua, one owner (my next store neighbor) thinks the Bakfiets is assume but had never seen one before and they have no cargo bikes even though they have 3 very large stores. The other store I went into as I brought out my old mountain bike to peddle next to my wife on Bakfiets and to start commuting to work every day this week and broke a spoke. When mentioning e-assist the owner (single person small shop racing specialty) was very rude and questioned the premise of why in the world would we ever add e-assist. Left it at its fine he doesn't get it, this bike replaces driving a car. Plan to use year round and not replace the second car. (the first is my work truck, which now no longer needs to be a commuter to second job, or cart kids around for errands.)

 

[Samd]

No sense reinventing the wheel. Sorry for the pun.

Ira's
http://endless-sphere.com/forums/viewtopic.php?f=6&t=48226

Bakfiets75's ride
http://endless-sphere.com/forums/viewtopic.php?f=3&t=50845

100W - a fellow Aussie: (check out the DJ bike)
http://endless-sphere.com/forums/viewtopic.php?f=6&t=41358&start=25

There's plenty of others on the thread.

I know when we did my wife's first cargo trike the BBS geometry wouldn't fit around the bottom bracket frame brace. I have my doubts about the smaller internal gears on the BBS units handling the backlash, I suspect a DD on the flat or a bigger geared unit for modest hills has long term merit.
Although my BBS02 is handling nearly 170kg payload these days. Time will tell.

 

[birdseye]

@KnNashua, I'm glad you're liking the bike. And thanks for the review of the brakes. That's good info to have.

@tfahrne, Sorry I confused you with the competition. You have a great store, always fun to visit when I'm in Portland.

 

[KnNashua]

Gonna buy kit, still concerned about mashing gears...

@samsavvas my thoughts on torque sensor was actually not the performance of variable assistance based on torque sensor (although that might be nice) but the fact that in videos of Bafang 8Fun I see that the motor continues briefly after pedaling stops (0.5s?). Through no knowledge of bikes or e-assist systems just my video observations I am surmising that the cadence sensor is the cause as it would take a half sec for speed to drop and having a torque sensor might eliminate that delay in controller knowing to cut motor (my guessing, as this will be my first and not sure if right.) Back to mashing gears, having a half second additional motor running makes me wonder what it is like to down shift on a steep hill and does it take getting used to/is an inconvenience or not.

Not sure if just stop pedaling for sec or flicking brake will seem easier. Hooking the shifter up to a system sounds complicated and might make it hard to pair whatever shifter you want with system but adding a quick motor cutoff button would be easy and might be nice, wondering. Have bike, getting kit, will see how easy it is to shift and let drive train have nice long life. If it doesn't I'll just blame my wife a it certainly couldn't be my shifting

 

[tahustvedt]

The Bafang continues to run for 0,25 s after you stop pedalling, in its stock form. It can be programmed down to 0,04 s with a programming cable, but that means it will cut out if the cadence is very low. I have tested.

The motor does actually try to adjust the power acfording to your input, but it only follows the cadence. I confirmed this by running the bike with the wheel off the ground in a stand, and the motor slows down and accelerates according to the the cadence of the crank.

 

[samsavvas]

Gonna buy kit, still concerned about mashing gears...

@samsavvas my thoughts on torque sensor was actually not the performance of variable assistance based on torque sensor (although that might be nice) but the fact that in videos of Bafang 8Fun I see that the motor continues briefly after pedaling stops (0.5s?). Through no knowledge of bikes or e-assist systems just my video observations I am surmising that the cadence sensor is the cause as it would take a half sec for speed to drop and having a torque sensor might eliminate that delay in controller knowing to cut motor (my guessing, as this will be my first and not sure if right.) Back to mashing gears, having a half second additional motor running makes me wonder what it is like to down shift on a steep hill and does it take getting used to/is an inconvenience or not....

Any 'run-on' is barely noticeable on my single person 20" wheeled bike and on a higher-rolling resistance box-bike I assume it would be even less obvious. And pulling slightly on the e-brakes kills the drive instantly anyway! With regard to avoiding shifting under load, the discussion started by Kepler is informative. He's obviously a talented engineer/problem solver and came up with his own convenient solution for momentarily switching off the drive. However others have also pointed out that feathering the brake lever is also a convenient way of killing the drive for a moment while shifting...

I'd fit the drive and then play it by ear - see what you think.

Savvas.

 

[Bikengineer]

The new Douze cycles look interesting.
Comes in 2 pieces, 3 lengths and BBS02 may fit above rather than below?
http://www.douze-cycles.com/en/

 

[KnNashua]

Douze looks awesome. Crazy split the difference rear frame steel, front aluminum.

If looking along the lines of a Bullitt or Cetma (thricely the form, function and price range) this should make a nice alternative. The variable cargo size like Cetma is nice, so Dutch, Californian and now French approaches to lightweight, high component, more aggressive riding style cargo bikes.

and if you are ok with fall first availability, and back order putting your purchase in sometime in winter and if you live in europe or willing to pay cross ocean shipping.

The Bafang midrive looks to fit in front of crank between the TWO frame tubes, lower than above with Cetma so good weight location, and better than clearance with putting below with Bullitt.

The two lower horizontal frame tubes would position a Stokemonkey mid-drive in a higher position, that amount of weight up high and the longer chain make this one worse for SM, but best of the 3 for a Bafang.

So it takes care a bunch of the minor issues that I know of in its direct competitors, but there are a couple I spot that are its own issues - maybe. (This bike is pretty different than the Bakiets I ended up choosing, the Workcycle version of the Bakfiets.nl cargobike long.) One thing to report is that Workcycle has been fast both in e-mail and in posted threads on and old blog to get me answers to specs to make sure the Bafang mid-drive will fit.

 

[KnNashua]

Bought Bakfiets month ago. (from Netherlands)
http://www.workcycles.com/home-products/child-transport-bicycles/workcycles-cargobike-long

Today got battery (50V/14Ah NCA / Lithium Nickel Cobalt Aluminum) and
Bafang BBS02 mid-drive motor with 500W controller (18 amp limit versus the 25A controller) both from EM3 (China)
http://em3ev.com/store/index.php?route=product/product&path=45&product_id=175

Got hardware, plywood and paint yesterday to make locking cabinet under bench to store battery.

Waiting on 42T chainring instead of using 48T Bafang comes (Italy)
http://www.alcedoitalia.it/shop/accessori-bbs/corona-42-denti-per-bafang-centrale-bbs01/

Since chain guard will not now fit will be putting Hebie Chainglider on (Germany)
http://www.starbike.com/en/hebie-chainglider/

When I complete build will put pic up.

 

[KnNashua]

Hmm never did up my step by step installation review, so I'll just let you know Bafang on Bakfiets works great.

My one comment is that the 500W is overkill, glad did not get the 750W, so the 250/350W for use in europe would be great and save on battery needed to match.

In summer used ~52 miles a week (84km/week) but now that it is winter and we have snow we put studded tires on and added canopy but have reduced to about 20 miles a week. We drop off daughter at Kindergarten every day then wife and 2 year old commute 8 miles round trip to her work. During nicer weather used bike path, but with snow more road usage. The motor does stick underneath but the clearance even on trails with roots and curbs has not been a problem. We have eliminated one automobile from our household and use one instead of two now.

We charge battery to 90% every other day used, but sometimes goes longer between. Want to avoid the one negative aspect I feel of controller, which is battery gauge, it stays on 100% then as soon as you hit 75% you know you need to charge soon.

Also the bottom bracket wrench needed for workcycle is not common here in USA, and the Bafang needs both a spanner and another very uncommon bottom bracket wrench. Other than that e-conversion was easy. Put battery under bench ion box. Was not able to get hebie chainglider to work with the Italian chain ring, so no chain guard so far.

Attached is photo from Halloween with wife biking to work with 2 year old inside.

 

[BikingIsFun]

I see you have a Workcycle Kr8 with Bafang and have had it since 2014. I am looking to put a mid motor on a 2 wheeled bakfiets very similar to yours. Are you still satisfied with the Bafang BBS02 500 watts?