Is mid-drive better, more reliable than a hub motor?

Fort Ord

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Hi, I’ve burned through 3 hub motor kits in 8 months. The original was the bafang 750 watt that came stock with the sh my bike. Replaced that with a voilamart 1500 watt kit, then an Ebikeling 1200 watt kit. Now I’m thinking I went down the wrong rabbit hole and should cut my losses and install a mid drive. Opinions greatly appreciated!
 

"A"

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It depends on what kind of riding you're doing, how much weight you're hauling how often you rely on the throttle vs PAS.
Without the specifics, it's difficult to tell which is better suited.
 

Fort Ord

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Ah. I’m a 168lb rider, generally carrying a 25lb backpack, and I commute 22 miles round trip (Marina -Monterey). Total elevation change is maybe 1000 vertical feet each way. I’m admittedly hard on the motor- I ride in traffic and average 25mph, stop signs and red lights included.
 

HumanPerson

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Hi, I’ve burned through 3 hub motor kits in 8 months. The original was the bafang 750 watt that came stock with the sh my bike. Replaced that with a voilamart 1500 watt kit, then an Ebikeling 1200 watt kit. Now I’m thinking I went down the wrong rabbit hole and should cut my losses and install a mid drive. Opinions greatly appreciated!
how big is your battery you been using for all these kits? volts and ah
 
D

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What exactly is going wrong with your motors? Broken gears, burnt windings, phase wires melted? What size wheels? How long do individual hill climbs last, at roughly what speed? Do you peddle from a standing stop, while accelerating, during hill climb? Are you killing the motor or the battery?
 

HumanPerson

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there are some that will disagree with me but i got a smokin deal on lunacycle.com with a BBSHD with offroad program and the
eggrider display to adjust settings. I ride only the streets and some soft trails ..mainly streets.

If you decide to go the mid drive route that may be an option for you
 

Fort Ord

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What exactly is going wrong with your motors? Broken gears, burnt windings, phase wires melted? What size wheels? How long do individual hill climbs last, at roughly what speed? Do you peddle from a standing stop, while accelerating, during hill climb? Are you killing the motor or the battery?
there are some that will disagree with me but i got a smokin deal on lunacycle.com with a BBSHD with offroad program and the eggrider display to adjust settings. I ride only the streets and some soft trails ..mainly streets. If you decide to go the mid drive route that may be an option for you
how big is your battery you been using for all these kits? volts and ah
how big is your battery you been using for all these kits? volts and ah
 

Fort Ord

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Hi, the battery is a joyisi 52v 20mAH. Prior to that, it was a bmw (bicycle motor works) 48v 18.5 amp. The issue with the present Ebikeling 1200 watt motor is a fried hall sensor. It is fixable though my concern is reliability. I use throttle primarily and pas uphills. Ebikeling has a warranty that does not cover shipping, so I can’t justify $300 for a round trip shipment to Chicago to get it fixed.
 

Fort Ord

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there are some that will disagree with me but i got a smokin deal on lunacycle.com with a BBSHD with offroad program and the
eggrider display to adjust settings. I ride only the streets and some soft trails ..mainly streets.

If you decide to go the mid drive route that may be an option for you
Hi, I appreciate the advice. What is the performance like from this kit?
 
D

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You broke THREE motors, and describe ONE, and ONLY ONE, failure. Hall sensor failures are reasonably common, the part is inexpensive, the fix is not complicated. Also it will work just fine with a sensorless controller for less than $100. Just need to get rolling from a stop. Easy fix, two different ways.

Did ALL THREE motors fail in the same way, this would be highly unusual.

The vendor recently mentioned is not one I would choose to do business with.
 

Fort Ord

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Ah. Good points you raise. The first motor, the Bafang hub motor, overheated and melted wires. i never took the time to figure out what happened to the voilamart, other than to find replacing the controller and battery didn’t solve anything. This one - the ebikeling - is a hall sensor failure. Thank you for the links - I’ll try running it sensorless and see how that works. I am curious to know if mid drive motor configurations offer better performance and reliability than hub motor
 
D

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The bafang was run at too slow a speed under load. That is how you melt phase wires, you did not specify but it is almost always these.

Likely the same problem with the voilamart. A DD hub has no moving parts internally, other than overheating it, which is VERY easy to avoid, they are damn near indestructable.

Do NOT go below 50% of max available speed under power for anything more than a minute or two. Pedal more, or get off the throttle. Get a temp sensor, and $20 worth of ferro-fluid additive for cooling, problem solved.

Crank drives require regular drivetrain parts replacement, and are easier to overheat than a hub. They are severely limited in total power available which can be run thru a bicycle drivetrain. High-powered hubs do not destroy chains and gears, and can be cooled very easily. Crank drives are also significantly more expensive.
 
D

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IF, repeat IF, you melted the phase wires on the 1500 watt motor, that would indicate your hills are pretty steep and/or long. Hence my question about time to clear the hill. I did use the phrase "a minute or two" in reference to overheating times, on this type of motor, it would be more like 3-5 minutes. If you could describe the specific symptoms of the failure, then it will likely be possible to isolate the environmental factors that caused the failure.

Also if it failed while actually climbing a hill, or some other factor. Hall sensors can fail due to heat, however more often the component itself is just bad, or fell out of position, either due to severe vibration or shock, or just bad glue. The part itself is a few dollars, you need to open the motor, install new sensor, and solder a few wires. Putting the motor cover back on is a bit tricky, the magnets will powerfully yank the cover out of your hands and you need to make sure all fingertips are clear. There is a "KLANG" video which shows this quite convincingly.

Only by knowing how and why the failures occurred, can suggestions be made to avoid the problem in the future, on your next kit.

Beware the crank-drive salesmen. A fair number of people on the internet get paid, actual dollars, to push crank drives. Dealers who engage in such practices generally do not get a recommendation from me. For some dealers, this is only one aspect of their business practices and modes of operation, some of which are truly horrendous. Such dealers I categorize as people I would not do business with.

The crank drive has it's place, if you have severe hills and enjoy doing extra drivetrain maintenance and do not want to do the research to choose the proper hub motor for your situation, they might be a good choice. BUT, a properly chosen hub motor will do the job for less money and less hassle.

Also, with most hub motor failures, you can still pedal the bike home. If an overpowered crank drive breaks your chain, or snaps off a clear cluster, you are walking all the way.
 
D

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For instance - The same hub motor will usually come in at least two seperate, very different, "windings" or "turn count". One is made for more speed, one is made for more torque. A hi-speed motor, in a wheel of 26" or more, will not climb hills very well, and will quite likely overheat easily. Put the same motor in a 24" or smaller wheel, and it will climb like a mountain goat. The hi-torque version will climb much better on a 26" wheel.

Some controllers are capable of running in sensorless mode, others are not. Trick is to get rolling before applying any throttle. The Halls are used for timing, and primarily smooth out starts from a standing stop.

Taking off from a stop is similar in motor stress, and heat, to climbing hills. A little less throttle and some brisk pedaling under initial acceleration can reduce the stress drastically, and increase both motor and battery life.
 

Fort Ord

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Man... lots of moving parts to this equation. The genesis of my interest in a mid drive as an alternative to a series of hub motors, comes from a video posted by John Nerdout, aka John Lange, with a laundry list of reasons why mid drive is better, faster, stronger, more reliable, etc, than hub motors. I'm not a wealthy person, and I need cheap reliable transportation while saving $ for a second car (wife needs the Volvo more than me, and we have a driving-age daughter). What I am concluding, rightly or not, is I'm going to get a second motor, take the existing one out, try to replace the hall sensor and keep it as a backup. I'm neither an electrician nor the most mechanically savvy guy but I can follow directions from a youtube video. I'm really grateful for the responses from all. My riding style is to begin from a stop by pedaling and using the throttle, same while riding uphill. What will help me a lot are the suggestions to improve the longevity of hub motors, like a temp sensor and ferro-coolant. Many thanks to all for your support. This ebike thing has been a lot of learning-as-I-go and some really expensive wisdom acquired along the way.
 

Yogaduke

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In short. A mid-dive is much better on hills then a hub. I have 4000 miles on mine. If you are willing to ride a e-motorcycle with more then a 1000wts. Then go for it. Just don't get into an accident.
 

"A"

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Relying solely on the motor (hub or mid) in steep hills is going to cut short on its lifespan.
Sustained 25 mph operation doesn't help neither.
But if you're averaging 25 mph, that means there are plenty of time you spent above 25 mph, too.

My LBS that mostly sold & service mid-drive ebikes are having severe drive chain shortage, not only on ebikes, but also on regular bicycles.
There are consuming 4x more chains than their regular supply.

That's the one draw back that you cannot change about mid-motor ebikes, you're stuck once your chain is broken.
Even though mid-drive ebikes costs are coming down, FAST, the fact that you will still need a chain to operate, sustained higher speed & uphills are going to wear on that chain just that much quicker.

E-motorcycle may be an option, but they would require registration & insurance, no?
 
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