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Leaf / leafmotor / leafbike high efficiency 1500w motor

I'll verify next time I have the motor off, but fairly certain it's a bog-standard HG Spline M at 35mm. It has an HG31 8speed 11-34t on it, and don't recall having to use any spacers on it.

If you can fit an 8 speed cassette.....then it has the 35mm freehub body.

For people who want to pedal their bikes (using light motor assistance to extend range) having up to 12 gears will definitely help.

The Leaf Bike 35mm is quite efficient at part throttle. Example below using 6T winding and 22.5" diameter tires:


However, some people don't do well bio-mechanically with the wide q factor that comes with having the 170mm rear spacing.

Unfortunately, the 137mm 35mm motor only offers 7 speed cassette. For me this would not be enough gear selection to entice me and instead I would rather choose the dish-less 35mm single speed coupled to a very small diameter (but wide) tire and take the motor efficiency gain.

Motor efficiency advantage of small diameter tire + strategically chosen single speed gear > less efficient motor (because of larger diameter tire) + 7 speed pedal gears.

But this 170mm also allows the motor efficiency of the small diameter tire but then lets a person have more gears. The downside, of course, is wider q factor than the single speed.
 
7 speeds is totally fine on such a powerful motor. Most people are running a few KW on this motor and the need to change how the 100w human rider is geared becomes an afterthought pretty quickly. I only used 3 or 4 gears.
 
7 speeds is totally fine on such a powerful motor. Most people are running a few KW on this motor and the need to change how the 100w human rider is geared becomes an afterthought pretty quickly. I only used 3 or 4 gears.

But how small of a tire diameter can you really use with 137mm rear spacing and 7 gears? This especially on a bike with a lot of weight on the rear tire.

There is only so far a person can go without increasing tire width.

8 to 12 speed Cassette on 170mm and Single Speed on 135mm are always going to allow a wider tire (and thus greater potential for smaller tire diameter) than 7 speed freewheel or cassette on 137mm.
 
Technically you could get this motor in a 18" wheel if you liked.
You could run a 2.8" wide tire and be happy with just 3 gears on the 135mm model, given you're running it above 3kw ( as it deserves :) )
 
Technically you could get this motor in a 18" wheel if you liked.
You could run a 2.8" wide tire and be happy with just 3 gears on the 135mm model, given you're running it above 3kw ( as it deserves :) )

I guess it depends on the bike frame, riding conditions and the load (e.g. going up a hill increases weight transfer to the rear).

A purpose built single speed fat bike with 68mm BB and 135mm rear can handle over 4" wide tire due to having enough chain stay clearance. Same goes for the 8 to 12 speed cassette on 170mm.

As you know the smaller the tire diameter gets the more powerful and/or cooler the motor becomes. The greater the tire width becomes the smaller in the diameter the tire can become for any set of targeted metrics.
 
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To me it just looks like one more thing to break.
It can cause some problems because the axle gets twisted in both directions with Regen. The twisting can work things lose and/or wear them if you don't keep everything tight.
 
How is it not simple? You just pedal backwards a bit....the greater the distance you pedal backward the stronger the Regen braking.

It may be simple, but not natural unless you’re 6 years old. After decades of braking on bikes and motorcycles, I’d rather rely on natural instincts when it comes to the necessary reaction time. It’s probably a good option for seniors with arthritic hands though.
 
If you use a good torque arm setup, and the bike's dropout was not abused to the point where it has motion already, you shouldn't have any problems with regen.
My setup is similar using the Grin TA parts and longer arms. The flats on one side were machined slightly smaller, so I made a shim out of a piece of straight razor and hammer it in between the axle and TA to get rid of the slop on that side. Tight TAs saved me once when I went for a ride, but forgot to tighten my axle nuts.

I miss regen. Not having it has completely change how and where I ride and the routes I take. I think I’ve lost about 15% of my range due to a combination of routes and not being able to count on recovery.
 
I just "finished" my Leaf bike (hopefully I'll get around to posting a build thread soon) and it's my first bike that has regen, first DD hub motor, and so far I really like it. I just have a throttle on the right and a regen throttle on the left, that feels about a intuitive as it gets. Still have to figure out exactly how high I want to set the regen current, that is the limiting factor really. You can't charge any battery nearly as fast as you can discharge it. My battery will do 200A discharge but only 12A rapid charge according to spec but I'm thinking I'll be pushing that charge a bit for regen. How many amps of regen are you guys using and what is your battery rated for?
 
I ran ~20A on a 47v nominal battery, about 1kw of braking.

I could have ran less, but i wanted to minimize front brake usage when stopping from 45-55mph because at those speeds you are severely range-challenged with today's battery technology.

It was a very aggressive amount of braking and 10-12A is allright if you're combining with friction brakes, or you're gong a lot slower than me :)
 
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It may be simple, but not natural unless you’re 6 years old. After decades of braking on bikes and motorcycles, I’d rather rely on natural instincts when it comes to the necessary reaction time. It’s probably a good option for seniors with arthritic hands though.

Yes, it is a simple system.

As far as natural instincts go motorcycles are different than bicycles:

Motorcycle has rear brake controlled by pedal on right side and front brake is controlled by hand lever on right side. Bicycle has rear brake controlled by hand lever on right side and front brake is controlled by hand lever on left side.

But what does this have to do with Regen?
 
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Yes, it is a simple system.

As far as natural instincts go motorcycles are different than bicycles:

Motorcycle has rear brake controlled by pedal on right side and front brake is controlled by hand lever on right side. Bicycle has rear brake controlled by hand lever on right side and front brake is controlled by hand lever on left side.

But what does this have to do with Regen?
I agree, but you’re the one who brought it up.

I’m just saying that pedaling backwards as a natural movement to apply brakes is something lost after you turn ~7 and get a bike with real brakes. You never really go back after that. If you continued to use coaster brakes after adolescence, then maybe it feels natural to you. I choose safety over gimmicks.
 
I think it's fine, would make converting a single speed a lot nicer.
 
I’m just saying that pedaling backwards as a natural movement to apply brakes is something lost after you turn ~7 and get a bike with real brakes. You never really go back after that. If you continued to use coaster brakes after adolescence, then maybe it feels natural to you. I choose safety over gimmicks.

If you are choosing safety as you say you would also have mechanical brakes on the bike and not run regen as your only form of braking.
 
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How many amps of regen are you guys using and what is your battery rated for?
70A peak regen phase current, 30A peak regen battery current, pack has 25p of 35E cells rated for 1.7A "standard" charge current, so about 0.35C peak.
 
I need to order spokes to lace my 24" SE RACING J32S rim to my 1500w Leaf motor...does anybody have ANY of the dimensions I will need to use a spoke length calculator?

I have asked Leaf in the past and I got no help.

My calipers will only go up to 6 inches.

Thank You
 
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Seems like I have seen "blueprints" of some leaf hubmotors here on ES. For the rim, where did you get it? See if they can tell you the ERD and spoke hole offset, if any.
 
I need to order spokes to lace my 24" SE RACING J32S rim to my 1500w Leaf motor...does anybody have ANY of the dimensions I will need to use a spoke length calculator?

I have asked Leaf in the past and I got no help.

My calipers will only go up to 6 inches.

Thank You
The outer flange diameter is 243mm per a few diagrams. You need to subtract the distance between the edge of the flange and center of the spoke hole (times 2). 232mm seems to ring a bell, but take a measurement with your calipers for the exact amount to subtract.
 
I need to order spokes to lace my 24" SE RACING J32S rim to my 1500w Leaf motor...does anybody have ANY of the dimensions I will need to use a spoke length calculator?
for my rear motor with 170/177mm dropout fitment, cassette option, I measured:

flange diameter at spoke holes: 233mm
flange spacing: 50mm
 
for my rear motor with 170/177mm dropout fitment, cassette option, I measured:

flange diameter at spoke holes: 233mm
flange spacing: 50mm

On Bullfrog's 7 speed freewheel motor the flange spacing is 40mm per the dimensional diagram. This measured from the outside face to outside face of both spoke flanges. Assuming the spoke flange is 3mm thick that means the distance between the middle of both spoke flanges would be 37mm.

Speaking of distance between spoke flanges, he will also need to know the dishing offset.
 
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