Geared Rear Hub Motor Durability

[Ken M]

Let me suggest two videos that are very informative. One is directly related to how well a geared hub motor performs. Being in Europe, it's limited to 250 watts nominal. You can see it here.

The other is a demonstration of how well the Crosscurrent S performs in hilly terrain. Longish video; the hilly part starts about halfway through. It can be seen here.

Draw your own conclusions. I think you'll find these more useful than another long post.

I don't question the performance of the geared hub motors especially when the goofy low power limit is considered - a 250-350W direct drive would not be adequate for good performance. In reality the power regulation in Europe and the US is nebulous because motors alone can't be defined by a power rating data point like that no matter what the eBike OEMs try to tell you.

When you get to 750W (still not a good way to specify a motor but it's a scale so I'll use it) and higher peak power a direct drive hub motor because a worthy eBike drive motor.

I think the long term reliability more than makes up for the lower torque to wattage capability. Keep in mind that geared hub motors kind of peak out at 500W because too much higher and the gears have to be made more robust to have a decent life cycle. My engineering mindset just tells me to go gearless if the performance meets your needs.

Note: The vast majority of hot rod DIY ebikes are large gearless hub motors rated from 1500-3000Ws with the higher power models being able to hit 35mph+ speeds with throttle only mode. I think the rider should have to pedal to be a bike and I think at some point the power is overkill because a cruise speed around 35mph/55kph is going to feel very fast on a bike for even good riders so anything faster really should be a DOT approved and street designed moped or motorcycle.

 

[Alex M]

Mike's - good point on "unique" motor in Juiced Crossurrent S.
It is indeed a custom motor specifically for Juiced. Directly related to service/repairability concerns. For a budget consumer it would be wise staying away from proprietary parts.

 

[Jeffrios]

Jeffrios...where are you located? If in the Denver area maybe we should try to hook up and you can take my bikes for a spin. I don't want to plug sales on EBR but I'm working with PIM on an urban commute model eBike with carbon forks, integrated bars/stem, and suspension seat post (like the Canyon / Ergon flexible carbon seatpost - actually very effective at absorbing most road vibrations and smaller impacts). This model will be available last April but I have a prototype in Denver.

I'm in Minneapolis. Thanks for the offer!

 

[Reid]

Mike's - good point on "unique" motor in Juiced Crossurrent S.
It is indeed a custom motor specifically for Juiced. Directly related to service/repairability concerns. For a budget consumer it would be wise staying away from proprietary parts.

I do not suppose it is a unique to Juiced motor, certainly not in any of its wear-out parts. That's just my educated guess. Let me snap a photo of all the markings on my "650W" advertised, CCS hub motor from the 2nd CCS production.


It is entirely possible to over-rate a motor with conservative factory ratings, for application to a duty that in practice, never mind the maker's conservative ratings, that it can provide reliably.

I have always known my motor to be "500W" rated by Bafang. But Juiced runs this motor as hard as over 650W, indefinitely. That's what I am doing at 25mph and above. However, I am not grinding up long grades or operating in really hot weather.

Mike perhaps has not seen this motor and bike in person.

And perhaps Tora will come in and explain his firm's over-rating this hub motor.

For myself, it is a non-issue. And it is just my opinion based on educated guess at this point, that this motor is not special in any proprietary way. You could always get another, or a direct drive motor or so on.

PS: unrelated: While pedaling home from an errand an hour ago, an Uber Eats bike driver turned into the road right ahead of me. So I got to follow him for 3/4 mile on a straight and level road. I only saw his bike from 30 feet away for a moment before he accelerated away while I yielded to a turning car. His bike had a direct drive rear hub and a large, rear rack slide-in battery. He did not pedal at all. He quickly got up to 27 mph against a stiff headwind and I struggled to keep pace 200 feet behind.

But I do not want a direct drive motor. I don't like magnetic cogging when I pedal a bike unpowered.

 

[Chris Hammond]

According to Juiced website the CCS motor is specked specifically for Juiced. (My guess is this is related primarily to motor output and high speed winding). That said, you are probably correct that the wear parts, (primarily the nylon/plastic planetary gears) are probably used in most Bafang geared hub motors as most are using a 5:1 reduction. The housing would be the big deal if you wanted to replace the whole motor, and again I would guess this is the same housing Bafang uses for most of its 135mm motors.

 

[bob armani]

I don't question the performance of the geared hub motors especially when the goofy low power limit is considered - a 250-350W direct drive would not be adequate for good performance. In reality the power regulation in Europe and the US is nebulous because motors alone can't be defined by a power rating data point like that no matter what the eBike OEMs try to tell you.

When you get to 750W (still not a good way to specify a motor but it's a scale so I'll use it) and higher peak power a direct drive hub motor because a worthy eBike drive motor.

I think the long term reliability more than makes up for the lower torque to wattage capability. Keep in mind that geared hub motors kind of peak out at 500W because too much higher and the gears have to be made more robust to have a decent life cycle. My engineering mindset just tells me to go gearless if the performance meets your needs.

Note: The vast majority of hot rod DIY ebikes are large gearless hub motors rated from 1500-3000Ws with the higher power models being able to hit 35mph+ speeds with throttle only mode. I think the rider should have to pedal to be a bike and I think at some point the power is overkill because a cruise speed around 35mph/55kph is going to feel very fast on a bike for even good riders so anything faster really should be a DOT approved and street designed moped or motorcycle.

Your statement: 'a 250-350W direct drive would not be adequate for good performance'. I currently have a 350W rear hub on my stock ebike and from my personal experience has plenty of power/speed and performance is top notch when on flats and climbing. Perhaps it may depend on the manufacturer?? Just my 2 cents...

 

[Ken M]

Keep in mind it's not only about how well geared hub motors perform relative to direct drive hub motor. The typically produce more torque per watt because of the gearing advantage but at higher speeds that advantage diminishes and there is the wear / reliability factor of the gears themselves. I simply think the overall advantage shifts towards direct drive hub motors for speed pedelecs that are used very frequently for commuting (the performance will be very close but the cost of ownership long term will certainly favor the direct drive motor - simplicity has it's way of winning some market comparisons).

 

[Ken M]

Your statement: 'a 250-350W direct drive would not be adequate for good performance'. I currently have a 350W rear hub on my stock ebike and from my personal experience has plenty of power/speed and performance is top notch when on flats and climbing. Perhaps it may depend on the manufacturer?? Just my 2 cents...

Hi, You did not mention if 250-350W hub motor is geared or direct drive. The geared are pushed because the market size is much larger because of the power limitations in Europe and parts of Asia. The higher power limits in the US shift the balance towards direct drives in my opinion but I still think the lower powered geared hub drives are better for the occasional rider because they may never wear out even the 1st set of gears.

Also EVERYONE that owns or is interested in owning a ebike should read about why wattage power ratings are nebulous at best. Sadly the legislators that create the laws usually lack the intelligence and knowledge to understand what they are doing which results in poor technical legislation on eBikes and the huge debate that is raging on how best to accommodate ebikes for everyone.

http://www.ebikes.ca/learn/power-ratings.html

 

[trekenridge]

So the question was, How long do plastic gears last ? I have a front hub bafang Moter with 3000 miles on it and I am getting some new noise that i am sure is coming from the front hub! Should i be concern.

 

[Kmraist]

I bought a Nakto 26in fat tire cruiser 36v 10ah 350w rear hub gear drive. I weight 140 lbs I commute 20 miles round trip 6 days a week normally loaded with 50 lbs of gear. It's lasted me 1700 miles. It's starting to get tired but I love it. 48v setup in the mail.

 

[mrgold35]

Update: I'm around 7200 miles between my two 2016 Radrovers. On my second set of brakes and third set of tires for each ebike. Other than that, everything else from ebike electronics/motor/battery to regular MTB parts/frame are operating normally. Still going strong hauling around +300lbs on the Rover with rack, commuter backpack, gear, and myself.

 

[harryS]

It's starting to get tired but I love it. 48v setup in the mail.

Nasty gearish noises?

 

[Deacon Blues]

If you're considering a Juiced ebike and want quality electric components you may want to look at the HillEater.
The bike has a motor, controller, and battery from Grin. Grin is known for producing quality products.

(Link Removed - No Longer Exists)

 

[Alex M]

Nobody here is considering anything . The theread is/was 2 years old, before Kmraist post.

 

[Deacon Blues]

Ha, I just looked at the date.....