Geared Hub Motor Quality

[neptronix]

Back to watts, every ride will have a max watts and an average watts. My max watts ever was 1778, the average max watts for 23 rides totaling 720 miles is 1420 watts. .... Note: max amps ever were 32.5 amps, if the controller was reset to 40 amps max then the top speed might be higher, but there would be more chance of breaking the rear dropouts or swing arm.

Oh, you barely touched what a MAC is capable of... and you would need higher voltage to achieve top speed because you have such a slow winding. A MAC can fairly safely handle 2500w peaks without worry of mechanical failure

I'd rather have the rear GMAC rear hub motor because it uses round axles ... it uses a specific controller and the kit cost lots more than my regular MAC motor and 12 FET controller from EM3ev.

There's no need for any specific controller with the GMAC, other than a high commutation rate which a majority of controllers now have.. You could reuse your infineon clone controller from EM3ev. Just don't expect features like variable regen, the quiet drive of a FOC, linear throttle action, etc.

 

[neptronix]

There's a megawatt Leaf motor?

That would be nice.. :lol:

We'd be doing the same with a GMAC. But at this point it seems to be academic - every single GMAC owner has apparently opted for a Baserunner or Phaserunner controller, likely for the "electronic freewheeling" feature as much as anything else, so it's immaterial whether a common Chinese controller could easily be configured for one. If there's a special setting for fixed regen appropriate to the GMAC as a geared hub, no one knows what it is. It's a point of dispute between several people who don't have a GMAC and can only guess.

It's most likely that people run baserunners and phaserunners because GMACs are a grin technologies product and so are the forementioned controllers. These are often sold as a package.

Same as with MAC motors that were sold for a decade by em3ev. People usually ran em3ev infineon clone controllers with them because they were sold as a pair, and no rewiring of connectors needed to be done. But there's 50 other controllers that would have been fine to run a MAC with.

A fixed amperage point for regen with a cheap and basic controller will vary depending on the bike and the weight of the rider. A 150lbs rider on a roadbike will want a different amount of regen than a 300lb rider on a fatbike. The same goes for the phaserunner setup. You'll want to tune the variable regenerative braking so that it does not exceed the grip of your tires at the maximum level.

 

[Bullfrog]

OK first off there is no bigger MAC/GMAC fan in the world than me BUT if you are going to ride a heavy bike off road with big tires...you need a mid drive where you can change the gearing.

I started with a 12T MAC and eventually laced it in a 20" wheel trying to keep it cool but it still got too hot (I pushed it hard off road at low speeds with a 52v battery/40A controller). The total weight of my set up including the rider was about 265 lbs. and with some hills and going fairly slow it WILL over heat. You can liquid cool it with ATF but that brings unique challenges of its own.

My recommendations for anyone are:

A. If you want to ride off road or less than 20 mph go with a mid drive (BBSHD is my favorite). Weight distribution affects handling especially off road and the mid drive helps get a reasonable front:rear weight distribution.

B. If you want to ride on hard surfaces at 20-30 mph go with a GMAC/MAC (I like the 10T).

C. If you want to ride over 30 mph go with a Direct Drive Hub Motor.

There are a metric shit ton of variables that can affect my recommendations but above is the "Readers Digest" version .

90% of the time I'd recommend a 52v battery with 18650 cells (I like 25R cells)...but there are unique circumstances where a different voltage, different 18650 cells, or LiPo batteries could be better.

 

[markz]

You can buy a MAC motor in a 6T to 16T
https://www.alibaba.com/product-detail/Mac-bldc-hub-motor-6T-8T_60512780782.html

I haven't found anything to back up a possible 16T winding. 16T is slower rpm/volt kv, thinner and longer winding wires for more resistance and heat but to mix and match for perfect setup then 16T could be an option, if genuine MAC factory builds 16T.

 

[onespeed]

Late to the discussion but I see only 1 of my candidates in this thread.

I have been hammering a eZee Grin geared front hub since buying it with a used Bullitt in 2019. The motor has performed flawlessly until the controller started to fail from a soldering point coming undone. I have been using the bullitt for household errands, brewery deliveries and to cart materials in the upkeep of my 3 family rental - it is always in use and it is used hard. I upvolted to 48v from the 36v battery it came with - so this motor has only been pushed to its limits in my possession, I have no idea how the prior owners treated it.

I dont know numbers or specs, I just know the motor delivers as expected and then some until the controller failed.

I have bought the replacement for the eZee - BMC 2000w geared hub, which I was surprised is not mentioned in this thread. It features largely in other threads as comparable to the MAC and better than the eZee. Will follow up here on how it performs after wheel build and install.

https://endless-sphere.com/forums/download/file.php?mode=view&id=287701
https://endless-sphere.com/forums/download/file.php?mode=view&id=287702
https://endless-sphere.com/forums/download/file.php?mode=view&id=287703

 

[Bullfrog]

Thanks onespeed.

Not sure if BMC has kept up with MAC or not...MAC has made some improvements in recent history where they went to thinner laminations, improved the gears and improved the clutch. At one point BMC was slightly better than MAC...I have no idea how they compare at this point.

 

[markz]

https://www.electricbike.com/hubmotor/

https://endless-sphere.com/forums/viewtopic.php?t=22103

https://www.electricbike.com/bmc-hub-motor-review/

 

[Bullfrog]

Good links but MAC has made changes since all of those ended .

A lot of their advancements were thanks to Paul at EM3ev and Justin at Grin Tech.

 

[Chalo]

As far as I know, MAC/BMC are the highest power capable geared hub motors out there. eZee is robust, but less so than MAC.

 

[Manbeer]

How badly do these things get beat up when used off road? i'm not talking about grinding up 5 to 10 minute inclines, Here it's generally pretty flat and the most climbing you'll do may be for a minute. Do the gears get pretty thrashed when you break and regain traction?

 

[Bullfrog]

How badly do these things get beat up when used off road? i'm not talking about grinding up 5 to 10 minute inclines, Here it's generally pretty flat and the most climbing you'll do may be for a minute. Do the gears get pretty thrashed when you break and regain traction?

Manbeer...I would not recommend a geared hub motor off road if you are going to hit things like roots/rocks/holes, etc.

I had the springs in my clutch get knocked out of place in my MAC and it made the clutch lock up. Not a big deal just no freewheel while coasting. BUT it could have been the opposite and made the clutch not engage. Best bet for off road is a mid drive like the BBSHD.

My advice to everyone is:

If you want to ride off road...mid drive/BBSHD.

If you want to ride on smooth surfaces up to about 30 mph...a 10T MAC or a 12T MAC if you only want to go about 25 mph.

If you want to ride on smooth surfaces faster than 30 mph...a Direct Drive Hub Motor.

If you are constantly starting/stopping, a MAC will over heat...another reason I would not recommend it off road. If you are riding on relatively smooth surfaces and less than about 30 mph...the MAC is a good choice. Just choose your winding i.e. 12T/10T accordingly.

 

[Manbeer]

You know, that's pretty much along the lines of what I was thinking but every once in a while I'll see like a guy running a Q 100 or something on a mtb So I just figured maybe they knew something I didn't. Agree on the mid drive, or massively powerful DD for flat fire roads and things

 

[Bullfrog]

Nice thing about a mid drive off road is it handles better than a Direct Drive motor in the front or rear due to weight distribution.

The MAC in the rear did not handle as good as the BBSHD in the middle when I pushed my bike harder off road. And of course a heavier DD motor would be even worse.

All three types of motors have advantages and disadvantages...just have to choose the best for your use.

I am a huge MAC fan and it has the best acceleration possible but I readily admit it has limitations if you want to run a lot of amperage continuously i.e. what is required to push the air out of the way at speeds over about 30 mph .

 

[Manbeer]

just to take things a step further than my previous question, i noticed many of the entry to mid level fat bikes on the market using hubs from bafang, shengyi and now even mac on some juiced iirc.

Presumably most will get minimal real off road use past dirt paths etc But do you figure hubs hold up any better on those fat tire applications? My gut would say no because of the longer axle but I'm wondering since I hear very little of failures on those bikes

 

[Bullfrog]

just to take things a step further than my previous question, i noticed many of the entry to mid level fat bikes on the market using hubs from bafang, shengyi and now even mac on some juiced iirc.

Presumably most will get minimal real off road use past dirt paths etc But do you figure hubs hold up any better on those fat tire applications? My gut would say no because of the longer axle but I'm wondering since I hear very little of failures on those bikes

IMO one big factor is everybody raves about their successes but keeps their failures pretty quiet. How many people do you hear about NOT winning the lottery for example.

Axle diameters are somewhat independent of the motor so you will have about equal failures with any long axle whether you have a motor back there or not...the motor just adds to the weight some.

A geared hub motor is a bad choice for off road IMO...I speak from experience and it is hard to keep them from over heating. A Direct Drive Hub IS the most reliable (only one moving part) but the weight can make it handle like crap.

Two big advantages to a mid drive off road...A. You can gear it to get the acceleration and speed you want as well as keep it cool and B. Handling...having the weight in the middle of the bike helps handling a lot based on my experience with a MAC in the rear wheel and a MAC is very light compared to most DD motors.

 

[Architectonic]

How badly do these things get beat up when used off road? i'm not talking about grinding up 5 to 10 minute inclines, Here it's generally pretty flat and the most climbing you'll do may be for a minute. Do the gears get pretty thrashed when you break and regain traction?

The clutches fail eventually when ridden offroad and I had to throw away my MAC motor after damaging the wiring after pulling the motor apart for the nth time to replace the clutch.

The gears and windings themselves are decent quality and can take quite a beating, though 2000w climbs meant the windings in my motor looked pretty crispy.

 

[Bullfrog]

How badly do these things get beat up when used off road? i'm not talking about grinding up 5 to 10 minute inclines, Here it's generally pretty flat and the most climbing you'll do may be for a minute. Do the gears get pretty thrashed when you break and regain traction?

The clutches fail eventually when ridden offroad and I had to throw away my MAC motor after damaging the wiring after pulling the motor apart for the nth time to replace the clutch.

The gears and windings themselves are decent quality and can take quite a beating, though 2000w climbs meant the windings in my motor looked pretty crispy.

Very true Architectonic.

I had my clutch lock up due to banging over tree roots and pot holes and that is another reason a geared hub motor like a MAC is not the best choice for off road. Luckily with the clutch locked, the motor still transmitted torque it just wouldn't freewheel so I was not stranded. On pavement or smooth surfaces, the clutch and gears are more than capable...I have been running 140A phase current to my 12T MAC for a long time without any problems. As far as temperature...as long as you keep the motor core temp below about 150C you are OK. Justin (Grin Tech) did some experiments to determine that and I backed it up with actual testing on the road. BUT that means you should not go over about 130C steady state because the temp rises rapidly from there if you climb a hill or stop and start a lot.

One last tid bit, I use Mobil 1 SHC 100 to grease the planetary gears. When my motor was new I covered the sun gear teeth with SHC 100 and I have never greased it since or had any problems with the gears. Mobil 28 is similar but uses a clay thickener as opposed to the soap thickener in the SHC. Either would be a good choice.