Leaf / leafmotor / leafbike high efficiency 1500w motor

[ebike4healthandfitness]

According to leaf bike, the 7 speed freewheel version of the 35mm is actually 137mm and the cassette version is 140mm....(both with dishing offsets and the cassette version having the largest dishing offset of the two)....but the single speed version of the 35mm is a true 135mm and centered perfectly in the middle making a dish-less wheel.

So it looks like to me this 35mm motor was designed around single speed as the primary goal with the multi gear versions being an afterthought. This, in contrast, to the original nine continent 27mm motor where the multi speed freewheel version was true 135mm and centered on the axle for a dish-less wheel (though with a narrow distance of only 28mm* between the spoke flanges).

* This, in contrast, to the 40mm distance between spoke flanges for the 35mm single speed leaf on 135mm and the 50mm distance between flanges for the 42mm single speed leaf on 135mm. Note: 42mm single speed on 135mm also makes for a dish-less wheel but does sacrifice the use of disc brake.

 

[ebike4healthandfitness]

For those of you contemplating a leaf bike front hub motor on 135mm fork spacing which would you choose?

Leaf bike 35mm wide stator (Dish-less on 135mm) with 40mm distance between spoke flanges and disc brake?

or...

Leaf bike 42mm wide stator (Dish-less on 135mm) with 50mm distance between spoke flanges and rim brake?

This with Regen? Or without Regen?

For me, assuming I have the proper rigid fat fork (i.e. thick clamping drop outs) or proper torque arms (i.e. Grin v7) it might be the 42mm. Though I am not sure how many moped rims would work with rim brakes? This means if I chose 42mm I would probably be limited to bicycle rims if I insisted on also being able to use rim brakes.

P.S. fat forks are sometimes also used on non fat bikes because the wider fork itself offers other advantages beyond the ability to house a fat tire. Example below:

 

[Bullfrog]

20S. I’m using an $80 no name dumb 80A clone (there are a bunch, rebranded). Not all listings show phase currrent, but one lists 80A, 240A phase. Mine came maxed at 60A so I shunt modded to 91A. It’s not as powerful launching as my old 70A, 200A phase controller, but that one peaked at 121A. This one feels stronger in the midrange though. Not programmable, like the real Sabvoton, so it can’t really be ridden without something like the Cycle Analyst to adjust the throttle signal. I bought 2 so I can swap it out if it gets fried.

Searching for a spare/upgrade controller

When it works can you draw a diagram for hooking up the C.A. plug.

endless-sphere.com

My econo-e-bike

If you look at APL’s build thread, he uses one but modded to something Ike 119A,

Thanks

 

[ebike4healthandfitness]

In this thread there was some discussion about rotational inertia and it's effect on acceleration. In post #2870 I gave an example of how an experiment could be done using two different factory leaf bike wheel builds.

With that said, here is someone who did the math on the effect of rotational inertia on acceleration from 0 mph to 15 mph:

Does rotational weight matter on a bike

My last post sparked some interesting discussion among some of my cycling friends: Not all weight is equal. The consensus was that weight on the wheels was more important (2x-7x more important) tha…

www.mikesoltys.com

According to him adding weight to a rim worsens acceleration 2.5% compared to adding the same amount of weight to the frame.

So if say someone adds 4 lbs to the bike frame we can all agree that will slow acceleration "a little bit"......well adding that same amount of weight to rim (rather than frame) only worsens that effect of "a little bit" by an additional 2.5%. This amounts to no noticeable effect in a real world situation! (re: "a little bit" x 1.025 still equals a "little bit")

P.S. Decades ago, there was a debate on whether or not rim width on road bikes using 23mm tires should be increased. The argument against wider rims was rotational inertia and total bike weight would be worsened. Well guess what fears about rotational inertia and total weight lost because the improvement in aerodynamics and rolling resistance (caused by the wider rim) actually made the bike accelerate and climb faster!

 

[scianiac]

Does it look like anyone else that his calculations are totally incorrect. Honestly I didn't try to follow him because he just uses whatever units he wants instead of showing the math with matching units but here is my math.

Lets say weight is 1kg, bike wheel is .66m in diameter (about 26in) and speed is 4m/s (9mph).

KE of weight on bike frame is easy, 0.5 * m * v^2 = 0.5* 1 * 4^2 = 8

Now the wheel, for simplicity and because we are mostly talking about rims and tires here, I'm going to use the moment of inertia for a hoop.

Moment of Inertia is I = m * r^2 = 1 * 0.33^2 = 0.1089

Angular velocity at speed is w = v / r = 4 / 0.33 = 12.12

KE of a rotating object E = 0.5 * I * w^2 = 0.5 * 0.1089 * 12.12^2 = 8

So the KE in the wheel is roughly (again used a hoop so it will be a little less) the same as on the frame so it's 2:1 which funny enough is pretty close to the rule of thumb.

 

[E-HP]

With that said, here is someone who did the math on the effect of rotational inertia on acceleration from 0 mph to 15 mph:

Does rotational weight matter on a bike

My last post sparked some interesting discussion among some of my cycling friends: Not all weight is equal. The consensus was that weight on the wheels was more important (2x-7x more important) tha…

www.mikesoltys.com

According to him adding weight to a rim worsens acceleration 2.5% compared to adding the same amount of weight to the frame.

So if say someone adds 4 lbs to the bike frame we can all agree that will slow acceleration "a little bit"......well adding that same amount of weight to rim (rather than frame) only worsens that effect of "a little bit" by an additional 2.5%. This amounts to no noticeable effect in a real world situation! (re: "a little bit" x 1.025 still equals a "little bit")

I plan to replicate my 0-30 mph tests, but it's acceleration while already at speed that provides greater safety when among cars, so that's what I care about.
What is your thought on how rolling resistance isn't dependent on speed, and so that when already at speed, acceleration at that point involves very little incremental rolling resistance, so observed gains or increase in performance would be more attributable to rotational inertia. I do think that when punching the throttle initially, there may be more deformation in the tire affecting acceleration though, even when already at speed though.
I did a few tests today to confirm my observations that acceleration is noticeably quicker. It definitely is, by the seat of the pants test, but I was only able to capture my first run before my GoPro died, and I forgot it takes a second for it to start recording, so the speed is at 20.1mph at the start. I'm at 1439W at the start, and feathering the throttle; you can see the watts drop to 1304W for about a second before hitting full throttle. So, not the best test but the time is good even with messing around with the throttle in the beginning.

I compared this with my test videos from almost exactly a year ago (which has several runs), and I can tell it's quicker now just from watching them, with the tires being the only difference.

 

[ebike4healthandfitness]

What is your thought on how rolling resistance isn't dependent on speed, and so that when already at speed, acceleration at that point involves very little incremental rolling resistance, so observed gains or increase in performance would be more attributable to rotational inertia.

Rolling resistance does increase with speed.

Furthermore, as I recall when you switched to lighter tires they were also narrower right? They were also slicks rather than knobby.

Didn't you also change tubes as well? Going from double inner tubes and sealant to only one inner tube.

Lots of changes going on there which are affecting rolling resistance. Then there are also aerodynamic changes as well.

 

[E-HP]

Rolling resistance does increase with speed.

Furthermore, as I recall when you switched to lighter tires they were also narrower right? They were also slicks rather than knobby.

Didn't you also change tubes as well? Going from double inner tubes and sealant to only one inner tube.

Lots of changes going on there which are affecting rolling resistance. Then there are also aerodynamic changes as well.

Ya you're right. The slicks aren't very narrow though. My rims are fairly wide. I haven't measured them yet, but they're beefier than I thought they'd be. Tire pressure is likely the biggest change anyway. They're a rougher ride out back for sure.

PS. Looking at that entry in my build thread, the runs last year were basically on slicks, since the pics of both show the tires had no tread left lol.

 

[ebike4healthandfitness]

Too bad there is not a US distributor for the 35mm wide stator single speed freewheel motor with disc brake on 135mm.

In addition to being a great motor it is the only motor with 135mm spacing that makes a dish-less wheel while also solving the wide q factor problem with fat bikes.

And yet nobody is picking this up?

 

[neptronix]

We've been running that motor with different casing since 2014 on the forum.
Nobody has reported problem with their leaf-built wheels.

Feel free to try it and report back but i think youre experience will be like ours but with a lot worse gearing options.

 

[ebike4healthandfitness]

We've been running that motor with different casing since 2014 on the forum.
Nobody has reported problem with their leaf-built wheels.

Feel free to try it and report back but i think youre experience will be like ours but with a lot worse gearing options.

7 speed freewheel version does not make a dish-less wheel and also does not allow for fat tires and narrow q factor together unless only one gear is being used.

Furthermore, leaf claims to me the 7 speed freewheel version is 137mm rather than 135mm. Maybe this fine for DIY standards but it not OEM standards.

Look, I'm not here to argue against the motor itself. We all agree it is a great one. I just see the single speed as the one fulfilling a niche.

 

[The Toecutter]

Furthermore, leaf claims to me the 7 speed freewheel version is 137mm rather than 135mm. Maybe this fine for DIY standards but it not OEM standards.

That explains why I have to pry the dropouts open with a flathead screwdriver upon installation.

 

[E-HP]

That explains why I have to pry the dropouts open with a flathead screwdriver upon installation.

I don't think any of the hub motor manufacturers include the necessary washers in their OLD measurements so there's always some prying. At least that's what it looks like in the diagrams; OLD is measure between the axle flats.

 

[neptronix]

Hub motors are typically +/- 3mm. I don't think i have actually owned one that was exactly 135mm.

 

[ebike4healthandfitness]

All my regular bicycle hubs (i.e. not hub motors) have always been 135mm on the dot. Every time.

Looking at Leaf bike's lowered powered DD hubs (e.g. the ones rated 36v 750w) I see the distance between spoke flanges is reduced from 40mm (as found in the 35mm motor) to 35mm. Furthermore, the dimensional diagrams for the cassette hubs also show the o.l.d. decreased from 137mm to 135mm. I haven't confirmed yet but It is logical to me this reduced dimension design has a reduced width stator motor.

So for someone wanting the cassette hub but is concerned about an o.l.d. that I was told was really closer to 140mm (not 137mm).....I'm thinking they could still get the cassette hub in 135mm but it would be a smaller motor.

With that mentioned, there is also the 42mm single speed. I was told this one was also true 135mm but could not use the disc brake. It has 90.5% efficiency like the 35mm motor but benefits also from thicker phase wires (5mm, rather than the 3mm ones as found in the 35mm motor). This while only adding 1.25 kg (2.75 lbs) weight over the 35mm motor.

Not only that but the 42mm is dish-less. This means I expect there will be less spoke breakage than what has been reported in this thread for the 35mm 7 speed freewheel set-up

P.S. For people at the planning stage (for a high power set-up) and deciding on buying 35mm + hubsinks realize the total price of those together is very close to the price of the 42mm by itself.