Nihola cargo trike, Bafang or Sunstar?

Hi there

 

We have bought a 2nd hand Nihola cargo trike (http://www.nihola.com/products/family.html) and I want to fit a mid drive kit to it. It will be my wife who uses it to pick up the kid from daycare, groceries etc. Daily it will run 12ish km with a 3% 1km hill. So she needs some help from the motor.

 

Seeing 250W is the only thing allowed on the roads here, I am looking at the Bafang BBS01 250W kit, but reading this guy's hands on installation of it on a Nihola: http://www.cairns-electric-bikes.com.au/bafang-250-watt-electric-bike-conversion-kit/ + the Bafang thread where some guy is giving warnings about any version that is not V1 or V4(?), I am not sure about it.

 

Our bike has a Sram 7S hub with freewheel, so with the larger chain ring in most kits we could probably balance it with a larger rear sprocket right? Most convertions I see, is on derailleur type bikes.

 

The Sunstar SO3+ is the "official" motor in the Nihola shop: http://www.sunstaribike.com/en/nihola-and-sunstar-the-ideal-combination/ but it is 2x as expensive as a Bafang kit...

 

Sunstar price for kit with 11AH rear battery in Copenhagen = 1180£ (most expensive, but close by if part of kit fails).

Sunstar price for same kit from http://www.electricbikesales.co.uk/ = 950£ (save 230£, but i'm guessing weeks for repair if something happens).

Bafang price with 13AH battery from http://eclipsebikes.com/ (saw someone mentioned them in a different thread) = 560£. This looks like a bargain, but battery must be mounted in cargo area + hassle with returns if needed.

 

Any advice?

Hi GPG,

 

Welcome to the forum.

 

You seem to be convinced that mid drive is the best solution, but what about a hub motor?

 

If you are in Copenhagen, you could check out these guys http://thunderfist.dk/

 

Here are a couple of their conversions

go for the Bafang BBS02 36V 25A 500W.

The Sunstar SO1, SO2 and SO3 have all been distinctly on the weedy side, giving what's best described as light assistance on normal bikes. For your loading I'd say definitely the Bafang and also save yourself some money.

.

The advantage of the Sunstar is the torque sensor instead of PAS. As you can buy a torque sensor for use with a hub motor doe $240 they are really overpriced IMHO.

I note you have an SRAM hub gear, ruling out a rear hub motor at present, but not completely since it's possible to convert to a derailleur gear with a hub motor wheel. Shimano make an add-on rear mechanism hanger that I've used to convert two bikes to derailleurs with rear motors and it works well. Here it is:

 

http://www.flecc.uk/t/images/Hanger%20Bracket.jpg

Thanks for the quick replies so far guys.

 

Cyclezee: It looks like I'd have to add a rear derailleur, new chain, shifter and chain ring if I opt for your kit. It is also listed as 350W on thunderfist's page, can you confirm this? Why would you choose this setup compared to a Bafang one?

Sounds expensive with a completely new gear setup and you can't shift gears while standing still (compared to the internal gear hub we have now), I know the wife is not very fond of change - she runs internal gears on her current bike. Maybe use the throttle to get going and then shift?

I do actually have one of those hangers flecc mentions, so thats good to hear he have had succes with such a setup. This setup seems a bit more messy with the external controller and gears.

 

Trex: Any reasoning for your advice?

I was indeed thinking of the 350W or 500W Bafang version seeing as the Nihola+kids+cargo is a lot heavier than the normal two wheeled e-bikes who uses the 250W motor. Won't the 25km/h limit still be there on a 500W unit, but this unit will just have an easier time helping with all the extra kilos? Would it deplete the battery much quicker too?

 

Is the torque sensor really worth all that extra money? I can imagine it would be great on a MTB, but for the daily steady commute I would think PAS is okay. I have no experience with it though!

 

I didn't know about the Sunstars "weakness", I'll look more in to that.

 

Also, I've seen chain ring adapters for the Bafang on ebay, seems like a good solution compared to having a custom CNC chain ring made for the Sunstar, those are like 60£...

 

Any advise on battery type? Would 13AH suffice for a 36V kit? This e-bike business is a real jungle to enter, so I am very happy with any questions you have the time to answer, also please just drop a link if I can then read up on it myself.

I didn't know about the Sunstars "weakness", I'll look more in to that.

 

I can only find one review claiming the Sunstar SO3 is powerful, that by Richard Peace for Bike Radar. However, he compares it to the Koga e-light which he also likes and which uses the Sparta direct drive rear hub motor, one of the low powered Dutch motors which suits their flat terrain. That doesn't give me much faith in his judgement. It's basically unchanged from the previous SO1 and SO2 versions but with a switched high power mode which gains a bit over those very low powered add-ons. Even their fan Richard Peace reported those in two earlier reviews as very low powered.

 

Our d8veh has tried the SO3 and like me, finds it low powered and says it's below 250 watt expectations. He feels it would suit a light folder, fitting with my impression that it's best for light assistance on a normal bike.

 

Power apart it's a quite sophisticated and smooth running system, albeit with some more buzzing noise compared to other good crank drives, but I just don't see it as enough for a Nihola in anything other than a flat area.

 

Also check on their battery prices, their largest is 12 Ah and could be pricey given the high kit price, and they only give a one year warranty when most now give two years or more.

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Edited April 26, 201511 yr by flecc

I´m with d8veh and flecc that the sunstar has to low power.

 

If I´d build that bike for my wife I would go for a Heinzmann,

convert the drop-out for cassette Motor and ready is a powerfull cargobike with 250Watt.

 

The Bafang 250Watt is in my eyes also to weak.

with 500Watt bafang it´ll work but it´s against the law.

 

so I see the Heinzmann or a other powerfull hub like the D-Bionx but no middrive

 

A lot of customer use the Heinzmann in cargo-bike´s like the "Bullit" and they are satisfied.

 

With www.cyclezee.com you have a quality dealer in UK for Heinzmann

Edited April 26, 201511 yr by mechaniker

I think that the OP has a point that you are all overlooking: you can change gear while stopped with an internal hub gear change (without mentioning his other half's preference for hub gears...). This can be very usefull in stop and go riding such as in a city like Copenhagen. Copenhagen, from memory is also rather flat (at least by my standards). So a Bafang BBSO1 with the controller reprogrammed to 18 amps and a healthy battery might just be up to that task n'est pas?

Thanks for the quick replies so far guys.

 

Cyclezee: It looks like I'd have to add a rear derailleur, new chain, shifter and chain ring if I opt for your kit. It is also listed as 350W on thunderfist's page, can you confirm this? Why would you choose this setup compared to a Bafang one?

Sounds expensive with a completely new gear setup and you can't shift gears while standing still (compared to the internal gear hub we have now), I know the wife is not very fond of change - she runs internal gears on her current bike. Maybe use the throttle to get going and then shift?

I do actually have one of those hangers flecc mentions, so thats good to hear he have had succes with such a setup. This setup seems a bit more messy with the external controller and gears.

 

Hi gpg,

 

My suggestion was really that you should try some converted bikes that are local to you in Copenhagen.

As Thunderfist have converted Nihola cargo bikes already that might be a good place to start before handing over money for anything.

It's true that you can change gear with hub gears when not pedalling, but it's not so easy to change gear when pedalling hard. It's the other way round with derailleur gears, so you get advantages and disadvantages with both.

...

I was indeed thinking of the 350W or 500W Bafang version seeing as the Nihola+kids+cargo is a lot heavier than the normal two wheeled e-bikes who uses the 250W motor. Won't the 25km/h limit still be there on a 500W unit, but this unit will just have an easier time helping with all the extra kilos? Would it deplete the battery much quicker too?

 

Is the torque sensor really worth all that extra money? I can imagine it would be great on a MTB, but for the daily steady commute I would think PAS is okay. I have no experience with it though!

 

I didn't know about the Sunstars "weakness", I'll look more in to that.

 

Also, I've seen chain ring adapters for the Bafang on ebay, seems like a good solution compared to having a custom CNC chain ring made for the Sunstar, those are like 60£...

 

Any advise on battery type? Would 13AH suffice for a 36V kit? This e-bike business is a real jungle to enter, so I am very happy with any questions you have the time to answer, also please just drop a link if I can then read up on it myself.

 

you could indeed go for the 250W BBS01, but the 500W gives quite a bit extra power when you need it, within the same 25kph speed limit, and costs only a little bit more. Will it deplete the battery more quickly? no.

Torque sensor: I have not ridden a cargo bike so can't comment.

Hmm a heinzmann kit looks to be as expensive as the Sunstar SO3+. I am still not sure on if the wife could grow accustomed to external gear shifting either.

 

I emailed Wooshbikes about the situation and I suggested the 500W Bafang. He said:"I am concerned that the 500W motor may overwhelm your 7-speed hub gear, 250W should be ok."

 

The bike is from 2007, 2nd hand and I have no idea about the hub's health. It runs fine now though. Sounds like if I go 500W I would have to upgrade the rear wheel. Shame its so hard to find 26" internal gear hubs built to order...

 

Maybe I should just go with the 250W version, keep it legal and no need to change gear setup (maybe a smaller chain ring + adapter).

 

I imagine the shifting experience with a mid drive varies a lot based on whether you run hub or external gears. Hub = no pedaling when shifting, I then assume the motor turns off due to PAS so one can shift? If so, then why does the kit come with levers to turn the motor off when breaking?

External = pedaling when shifting, but how is this affected with PAS? Won't it disturb the shifting as it will try to keep the speed up compared to PAS level?

Hmm a heinzmann kit looks to be as expensive as the Sunstar SO3+. I am still not sure on if the wife could grow accustomed to external gear shifting either.

Sometimes you get what you pay for, a bullet proof kit from a German manufacturer with a reputation for quality, reliability and performance.

I emailed Wooshbikes about the situation and I suggested the 500W Bafang. He said:"I am concerned that the 500W motor may overwhelm your 7-speed hub gear, 250W should be ok."

 

Woosh are right, 500 watts is too much for that SRAM 7 hub gear, especially on your bike. I manage to eventually break an SRAM P5 hub gear using the low powered early Panasonic crank unit Lafree by towing large loads, so similar loading to your application.

 

250 watts is about the limit for these gear hubs.

.

where are you going to put in a hub motor? there is a hub gear on your 26" rear wheel. BBS01 is the solution. Don't worry about gear change, it's quite easy to get use to blip the brakes and change if you are climbing a steep hill.

I read about a guy who added a "clutch" lever - a brake lever that was not connected to the brakes just to turn the motor off when changing gear. Was it someone on here? He said it looked weird - two brake levers on the left hand side - but it worked well for him. I thought that a push button would work just as well and be more discrete.

 

250W - you aren't going to be racing the thing nor climbing the Alp d'Huez?

where are you going to put in a hub motor? there is a hub gear on your 26" rear wheel.

 

We covered that earlier Trex, by fitting the derailleur adaptor to the frame instead, and in fact the OP already has one of those.

.

Sometimes you get what you pay for, a bullet proof kit from a German manufacturer with a reputation for quality, reliability and performance.

If only we had the money The product does look great!

 

Thanks for the heads up flecc.

 

Trex: Indeed, I would have to switch the gears + hub.

 

Great you posted again anotherkiwi, I was just about to quote you on the 250W reprogrammed to 18amp part. This sounds a bit above my skills, would it just allow the motor to draw more power from the battery?

Not at all for racing no, its the very careful wife+kid+the occasional groceries bags 12km every day a bit north of Copenhagen.

 

Will probably pull the trigger on a 250W Bafang kit soon. Then we can (almost) keep all the current components and it will help her far more than no motor at all! Still not sure if we can use the Bafang 46 tooth chain ring in place of the current 38 tooth, and just go for highest possible tooth count rear sprocket i can find.

 

What rear carrier battery would you recommend?

It can't really be any of the new "water bottle" type as there aren't room nor any screw holes on the frame.

Again, what a great community. Thanks a lot for the help so far. I will try and update the thread with some pics and my experience once everything has been ordered and I get on with the retrofit!

Still not sure if we can use the Bafang 46 tooth chain ring in place of the current 38 tooth, and just go for highest possible tooth count rear sprocket i can find.

 

The largest rear sprocket for hub gears is 24 teeth, SRAM and Shimano sprockest are compatible. One company launched a hub gear centre spider to which chainrings could be fitted for larger sprocket needs, but I can no longer find any trace of it.

 

There is a dodge you might be able to use for a smaller chainring on the Bafang though, bolt a chainring with the same number of spoke arms alongside with spacers. There's an illustration below from A to B magazine of a Powabyke adapted that way, in that case with a larger chainring. Chains can be run a bit out of line with almost no efficiency loss. Also the rear sprocket can be the dished kind fitted in some cases with the dishing outwards or inwards to suit.

 

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Hub gears are not good with any Bafang or similar crank-drive because the motor runs on a bit after you stop pedalling, so you have to wait a bit before you can change gear. It's OK going downhill, but no good doing that up a steep hill.

 

A 500w crank-drive will break your hub-gears. A 250w one probably would too. It would just take a bit longer. The gears are only designed for human power.

A 500w crank-drive will break your hub-gears. A 250w one probably would too. It would just take a bit longer. The gears are only designed for human power.

 

Yes, took me four years but the SRAM P5 hub gear broke in the end with the Panasonic unit shifting loads.

 

York Couriers business use the SRAM S7 that the OP has on their heavy cargo trikes and consider that much tougher than the P5 I broke.

 

Another point is that the repair is dead simple on the SRAM gears, just swap in the whole insert from a new one into the wheel's shell, cost me just £89 on the P5, not bad after four years of very hard load work.

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I was just about to quote you on the 250W reprogrammed to 18amp part. This sounds a bit above my skills, would it just allow the motor to draw more power from the battery?

 

It gives you 350W (the difference between the two motors is the controller amperage). It will use the battery quicker.

 

As d8veh says, you need to stop the motor before changing gears (downshifting) and the easiest way is to install the supplied brake lever and just touch the rear brake before changing down when going up hill.