Leaf / leafmotor / leafbike high efficiency 1500w motor

[Cowardlyduck]

I had FF 'disappear' from my Leaf motor after I ran it at 8KW with 10-15ml of FF as well as cooling fans and holes in the shell.
It took 8-12 months though and I just kept periodically topping it up without issue. Ran it like that for at least 2-3 years with zero problems despite the FF attracting dirt through the side cover vents.
I only ran it like that as an experiment because that motor was already modded for forced fan cooling and I wanted even more cooling to be able to run it at 8KW. It worked too.

Cheers

 

[calab]

Some were making their own recipe for f.f.

 

[E-HP]

I dont' have any links, but there are some posts around here about motors where all the FF / SA "disappeared" over time, and it had to be refilled.

I need to add more when doing maintenance, hopefully soon. There’s some stormy weather on the horizon, so it might be a good time.

 

[Bullfrog]

FF...depends on what carrier fluid is used as far as how rapidly it "disappears", assuming there is no leakage.

In addition to ATF in my MAC, I also ran distilled water and Motul MoCool, but not at the same time I was using ATF. The MoCool was added just as a corrosion inhibitor. The water/MoCool mixture worked great. It would disappear over time because my Mac would run about 110C and the boiling point of water is 100C so my guess is that it just boiled/evaporated over time. Nice thing about the water/MoCool mixture was that when it leaked on my brake rotor, it didn't cause any problems like leaking ATF did. The windings did get a dull sheen appearance but I ran it for over a year and never had a problem. I swapped to a smaller diameter rear wheel/tire to help the MAC run cooler and now I don't run any coolant inside the motor. I was concerned about the gears in my MAC not having any lubrication since I was running 60A battery/200A phase current to my MAC with a 52v battery but I never had any problems with the gears or the clutch. I weighed about 200 lbs at the time and my bike weighed about 65 lbs and I hammered the throttle WFO from a standstill every time I got on the bike so that is an indicator the gears and clutch are pretty tough.

Found my notes on the MAC water cooling....I used distilled water/MoCool (5% by volume). While the motor was installed on the rear of my steel framed hardtail I added the fluid through one of the brake rotor bolt holes positioned at 12:00 until it ran out of the bolt hole positioned at 6:00. The result was approximately five ounces of distilled water/MoCool mixture in the motor.

The power required to turn the rear wheel with the throttle wide open and the rear tire off the ground was 72 watts before adding the water mixture. After adding the water the power required was 150 watts. So ~78 watts of drag for the water mixture at wide open throttle and the wheel in the air. The MAC I did the experiments with was a 12T and I measured the wattages mentioned above with my Cycle Analyst. Keep in mind that the drag from the coolant during actual operation would be less due to a lower rpm when the motor is driving the bike as opposed to just spinning in the air without any load.

My Leaf (still in the box) is a 4T and it is laced in a wide 26" rim directly from Leaf. On 52v it may be OK but if I run it on 72v, I am pretty sure I am going to need additional cooling.

 

[E-HP]

The power required to turn the rear wheel with the throttle wide open and the rear tire off the ground was 72 watts before adding the water mixture. After adding the water the power required was 150 watts. So ~78 watts of drag for the water mixture at wide open throttle and the wheel in the air. The MAC I did the experiments with was a 12T and I measured the wattages mentioned above with my Cycle Analyst. Keep in mind that the drag from the coolant during actual operation would be less due to a lower rpm when the motor is driving the bike as opposed to just spinning in the air without any load.

My Leaf (still in the box) is a 4T and it is laced in a wide 26" rim directly from Leaf. On 52v it may be OK but if I run it on 72v, I am pretty sure I am going to need additional cooling.

Great info. I’m definitely going to do the before and after when I add more Statorade to measure the drag. Any reason you went with 26” instead of going to a smaller wheel right off the bat? I ordered my Leaf with the same wide 26” rim. They did a good lace job, but I made a decision on the fly when it arrived and relaced to a 24”.

 

[Bullfrog]

Great info. I’m definitely going to do the before and after when I add more Statorade to measure the drag. Any reason you went with 26” instead of going to a smaller wheel right off the bat? I ordered my Leaf with the same wide 26” rim. They did a good lace job, but I made a decision on the fly when it arrived and relaced to a 24”.

Availability of wider tires is probably the biggest reason I went with a 26" rim. I like to run a 26x3" tire just to get a little more "cushion" (pseudo suspension) since I am running a hardtail. The larger diameter will roll over bumps/obstacles a little better than a smaller diameter.

Interestingly, a 24" bicycle tire is about the same OD as a 17" motorcycle tire and 17" motorcycle tires are what is used on almost all new street bikes today. Plus the wheel diameter is the only way you can change the effective gearing of a Direct Drive or Geared Hub Motor. The best way to "go fast" without over heating your motor is to go with a higher speed winding like a 4T and put it in a smaller diameter wheel as opposed to a slower speed winding like a 6T and putting it in a larger diameter wheel.

I once had a MAC laced in a 20" rim and ran a 20x4" tire...it looked really weird with the 27.5" front I was using at the time but it worked great. The 20" rear/27.5" front did increase the Rake Angle so the bike steered a little too slow for me but it was super stable at high speeds.

 

[neptronix]

Consider a 22" BMX rim with a 18" moto tire scenario for a bike that originally came with 26".
Should have an effective outer diameter of 23".
I've confirmed that these fit.

A pic from my shop when i had it.

Back: 22" BMX rim with 18" x 2.5" moto tire mounted
Front: 20" x 2.4" - bike tire/bike wheel



I think 22" aka 18" is as good as it gets for cross motorcycle-bike tire compatibility but i'd love to be proven wrong.

 

[neptronix]

How was that mac in a 20"?
Absolutely nutty power i bet?

 

[The Toecutter]

Consider a 22" BMX rim with a 18" moto tire scenario for a bike that originally came with 26".
Should have an effective outer diameter of 23".
I've confirmed that these fit.

A pic from my shop when i had it.

Back: 22" BMX rim with 18" x 2.5" moto tire mounted
Front: 20" x 2.4" - bike tire/bike wheel

I think 22" aka 18" is as good as it gets for cross motorcycle-bike tire compatibility but i'd love to be proven wrong.

Do you know what size spokes are used to lace a Leafbike 1500W 3T 17.5kV hubmotor into a 22" bicycle rim or 18" DOT rim with a one-cross pattern? I have a 16" DOT rim for my 3T Leafbike with a Mitas MC2 16x2.25" at the moment, but it is still a bit small given the potholes around here, and with the Grin All-Axle 3T 20kV motors going to the front and ordered laced to 20" bicycle rims(and later to be replaced with 16" DOT rims), having an 18" DOT/22" bicycle sized rim in the back would allow all the motors to closely match in speed without having to resort to field weakening in the rear and the efficiency reduction which it would entail, plus I'd be able to go over potholes better and not have my rear wheel get caught in deep groves in the road. I could also have a wider choice in tires where I can switch between 16"F/18"R DOT tires and 20"F/22"R bicycle tires in a pinch.

 

[neptronix]

I'm sorry, lacing rims is the one mechanical thing i don't personally do and hand to someone else.
I use grin butted spokes on everything.

22" BMX rims and tires are popular enough to have a handful of vendors producing things for them.

 

[Chalo]

Do you know what size spokes are used to lace a Leafbike 1500W 3T 17.5kV hubmotor into a 22" bicycle rim or 18" DOT rim with a one-cross pattern?

That depends on the dimensions of the rim. Effective rim diameter varies among different rims in the same nominal size. Without that there's insufficient data for a precise answer.

 

[Bullfrog]

How was that mac in a 20"?
Absolutely nutty power i bet?

It was a 20x4" tire so about 24" OD. I was only running a 30A controller at the time so it had good acceleration but nothing like the MAC when I was running a 60A (battery)/200A (phase) controller and a 52v battery that could supply 60A continuously. Prior to the 20" fat tire, I ran a 20x2.0" tire (different rim of course) and the thrust/torque was unbelievable but the handling was pretty wonky with a 27.5x2.8" DHF on the front. My buddy called it the "Clown Bike" because it looked like it should be ridden by a Clown in the Circus. I was trying to take the overall gearing to an extreme to see if I could keep it from over heating when riding slow and climbing hills in the woods but even the 20x2.4" tire wasn't enough and it still got too hot. The nail in the coffin was when one of the clutch springs got knocked out of place while riding over big roots at high speeds...the bike was a hardtail. I went to a BBSHD for all of my off road riding after that. I still have and love my 10T MAC with a 26x3" tire for the pavement.

As you know, I am probably the biggest fan of a MAC motor alive today! It does have the limitation of over heating if you continuously run more than about 1,200 watts through it but for short term thrust, the MAC puts out more torque per battery amp than ANY ebike motor and that includes the Cromotor and the QS205/273 since the motor torque gets multiplied by the gear ratio i.e. 5X. "Continuously" above means about an hour at 1,500 watts for my bike. Of course more amperage means shorter times and lower amperage means longer times to over heat.

I just bought my "Leaf" because it is the best compromise as far as weight, power, simplicity, and not over heating. It is the first DD motor I have tried. I recommend the BBSHD for off road and a MAC for pavement if you are not going to exceed ~28 mph since any faster and you will eventually over heat or at least I did...a smaller diameter wheel/tire and a faster winding may allow you to go a little faster without over heating assuming you are not running any cooling fluid. Hopefully my Leaf will allow me to go faster for a long time without any issues.

 

[Bullfrog]

That depends on the dimensions of the rim. Effective rim diameter varies among different rims in the same nominal size. Without that there's insufficient data for a precise answer.

​

The Toe Cutter...I agree with Chalo. You will need the effective rim diameter, the diameter of the motor's spoke circle, and which pattern you want to use i.e. one cross, two cross, radial (which I would not recommend). Fewer crosses means wimpier, usually...I prefer a two cross...it is the best compromise for strength and ease of lacing IMO .

Once you have the dimension you need, you can use one of the online spoke length calculators. I forget which one I used last time but it worked great and was accurate. I believe Grin Tech has a pretty good one and you can call them if you run into any problems.

I'd recommend using the terminology "length" as opposed to "size"...most people will give you a gauge/diameter like 12 or 14 if you ask what size although we know what you meant .

I like Sapim spokes and Sapim Brass Polyax Nipples since I live close to salt water.

Chalo...what size spokes would you recomend...seems like I remember you saying 12/13 so you can get the proper spoke tension but I am going on memory and my memory is getting pretty sketchy in my old age. Thanks

FYI for others...the 12/13 gauge spokes are 12 gauge (larger diameter) for a portion of the spoke that attaches to the motor and 13 gauge (smaller) for a length that attaches to the rim. By doing it this way, you can get a stronger spoke where it attaches to the motor and the correct tension in the spokes. If you go too large in diameter with the spokes, you won't get enough tension and your spokes will get loose and they can fail from fatigue.

 

[Bullfrog]

I'm sorry, lacing rims is the one mechanical thing i don't personally do and hand to someone else.
I use grin butted spokes on everything.

22" BMX rims and tires are popular enough to have a handful of vendors producing things for them.

While researching 18" motorcycle tires on 22" bicycle rims, I found some more good info posted by a dude named "Neptronix" .

The holy grail for ebike wheels - 22 inch BMX rims = 18" motorcycle wheel diameter

Recently when shopping for oddball wheel sizes for my recumbent, i stumbled upon 22 inch BMX rims, which recently came into fashion. As of writing, there are at least 4 manufacturers of these rims. Here's some examples: https://www.modernbike.com/22-inch-rims A few of these rims come in 457...

endless-sphere.com

 

[neptronix]

As you know, I am probably the biggest fan of a MAC motor alive today! It does have the limitation of over heating if you continuously run more than about 1,200 watts through it but for short term thrust, the MAC puts out more torque per battery amp than ANY ebike motor and that includes the Cromotor and the QS205/273 since the motor torque gets multiplied by the gear ratio i.e. 5X. "Continuously" above means about an hour at 1,500 watts for my bike. Of course more amperage means shorter times and lower amperage means longer times to over heat.

You took my spot!
The mac is a great motor and I'm real sad i never got to try the mac with 0.27mm laminations.

I just bought my "Leaf" because it is the best compromise as far as weight, power, simplicity, and not over heating. It is the first DD motor I have tried. I recommend the BBSHD for off road and a MAC for pavement if you are not going to exceed ~28 mph since any faster and you will eventually over heat or at least I did...a smaller diameter wheel/tire and a faster winding may allow you to go a little faster without over heating assuming you are not running any cooling fluid. Hopefully my Leaf will allow me to go faster for a long time without any issues.

I think i'd still be the #1 leaf fan if i didn't like my bike wheels in the small range, which lets me downsize my motor and get away with smaller. You will be pleasantly surprised at it's efficiency relative to the mac.

It's a real shame that leaf hasn't innovated anything new in their motors for a decade though.

 

[Cowardlyduck]

If using a 22" rim to gain the benefit of running a 17MC tire, why not just lace up a 17" MC rim to begin with? Yes it's a little heavier, but meant for the job at least. To me this makes more sense....or am I missing something?

Cheers

 

[neptronix]

22" BMX rim takes a 18" moto tire.

MC rim gonna be significantly heavier and much harder to lace up to the motor, also the spokes would be too stiff for the application.

I wouldn't do it unless you're in the >10kw club!

 

[99t4]

Do you know what size spokes are used to lace a Leafbike 1500W 3T 17.5kV hubmotor into a 22" bicycle rim or 18" DOT rim with a one-cross pattern?

To calculate the spoke length you will need to know the rim ERD (and possibly the spoke hole stagger distance), the hubmotor flange diameter and width, and the dish (if applicable).

I found this info page helpful for my first (and only, so far) wheelbuilding effort:

Wheel Building - Learn

There are many good print and online references for lacing bicycle wheels. Many will defer to Sheldon Brown, Brandt's Bicycle Wheel Book, and others. However, a lot of the points and details with a conventional bicycle hubs don't necessarily apply to hub motors with their much larger flange...

ebikes.ca

The videos at the bottom of the page are extra-helpful.

For a bicycle rim, the Sapim Strong 13-14 butted spoke seems to be the sweet spot.

Sapim Strong Single Butted J-Bend Spoke

A butted spoke is drawn to its specific profile, which defines its high strength. The strongest spoke in Sapim’s product range, the Strong is developed for specific and heavy usage such as tandem, e-bikes or heavy load use. In case of large hub holes, the Strong is the recommended choice...

wheelbuildingparts.com

Spoke head washers may be required if the motor flanges are thin or their spoke holes are large.

Sapim Spoke Head Washer

Spoke washers help adjusting bending better to the hub. This washer adds additional reinforcement at the neck of the spoke.

wheelbuildingparts.com

 

[Bullfrog]

You took my spot!
The mac is a great motor and I'm real sad i never got to try the mac with 0.27mm laminations.



I think i'd still be the #1 leaf fan if i didn't like my bike wheels in the small range, which lets me downsize my motor and get away with smaller. You will be pleasantly surprised at it's efficiency relative to the mac.

It's a real shame that leaf hasn't innovated anything new in their motors for a decade though.

Is Leaf using 0.35mm laminations now? I think that was a relatively recent update but the only one I am aware of in the last 10 years.

Has MAC gone to .27mm laminations? The last MAC I bought was about 5 years ago. Unfortunately I used up my one time good deal where MAC allows you to order a single motor once...then they require a purchase of at least 8 items. EM3ev was my source for MAC motors as well as motors laced in a rim but they only sell batteries and the Bafang BBSxx motors now.

 

[scianiac]

I'm wondering if the upcoming 45mm Grin All-axle will be an improvement over the Leaf and fit in this use category, that is efficient (thin lams), powerful, reasonable weight and still suitable for a bike frame. An extra 10mm of stator in the grin but they are generally lighter per stator size due to better design so maybe only slightly heavier and lighter than something like a MXUS 45mm.

 

[gobi]

For light strong rims, I found some moped 17 inch rims, not cheap but there is a good selection of skinny 17 inch moped tires out there. I bought a few off treatland (steel) then I found some Al ones on amazon, not sure if the Al ones are DOT compliant.

 

[gobi]

I peeked leafbike and I am a bit confused on the mph vs T rating.

is 6T = 15mph?

how will a 6T perform with 300 lb load? (200 lb rider and 100 lb bike)

 

[neptronix]

Is Leaf using 0.35mm laminations now? I think that was a relatively recent update but the only one I am aware of in the last 10 years.

Leaf has had 0.35mm laminations since page 1 of this thread

Has MAC gone to .27mm laminations? The last MAC I bought was about 5 years ago. Unfortunately I used up my one time good deal where MAC allows you to order a single motor once...then they require a purchase of at least 8 items. EM3ev was my source for MAC motors as well as motors laced in a rim but they only sell batteries and the Bafang BBSxx motors now.

em3ev, maybe cutler mac also.. did a run of the motors with 0.27mm laminations before stopping selling them. Efficiency went up ~2%. This would improve the thermal scenario a bit ( good because this is the achilles heel of the MAC ).

I believe the GMAC today is using 0.35mm laminations.
Edit: i'm wrong, gmac has 0.27mm lams!

 

[Bullfrog]

I'm wondering if the upcoming 45mm Grin All-axle will be an improvement over the Leaf and fit in this use category, that is efficient (thin lams), powerful, reasonable weight and still suitable for a bike frame. An extra 10mm of stator in the grin but they are generally lighter per stator size due to better design so maybe only slightly heavier and lighter than something like a MXUS 45mm.

Looks like the 45mm Grin All-Axle motor is only going to fit Fat bikes with OLDs of 170/177 and 190/197 where the Leaf works for the smaller 135mm dropouts.

Being a Grin design, you know it is going to be a good motor but also a little pricey .

 

[calab]

Quality costs money