'lightest.bike' 1.7kg 1000w mid drive

[szkuba]

this is how get the proper setup of bearings and washers for square tapper 73mm BSA BB:

so as you see the most external bearing is actually alligned with the external edge of the bracket, then i substracted one washer (on picture are 3x washers but it should be 2x) so the cup could fully press the bracket to the frame
.


After that i tried to fit the chainring. The original placement was giving me 55mm chainline (crank not fully seated on axle).


So i mounted the spidedr on internal side of freewheel and is perfect:



Now the mounting is finished and chain installed as well. I am not able hovewer to find the PIN .
Also the chain is rubbing against torque sensor arm.

 

[neptronix]

Good! In the worst case scenario it is posible to change ISIS BB to square to solve problem with bearings.

Yeah i can tell you the square taper hardware is good, if not a bit on the heavy side.

I also now see why we it requires a special BB. The right leg crank appears offset by approximately 6mm because it is on the drive side.
This is better than the BBS02's 10-11mm offset but i thought there would be less offset.

I'm curious to see if things can be aligned as such that the special BB is not necessary. It looks like there is a lot of room to play with driveline spacing in this kit. I have some expensive lightweight / low friction BBs i'd like to reuse.

Worst case scenario is that this mid drive power unit goes in the mid drive of my semi recumbent bike so that i can get perfect pedal alignment. ( yes, there is a normal BB in the middle and up front! )

Will be working on figuring this out next week.

 

[neptronix]

Good information szkuba!!

 

[szkuba]

From the manual:
S11. Enter the 4-digit numeric pin found in the package in the "settings" screen of
the App.

Haven't gotten mine yet so don't know if that's accurate. I would have thought it would come with no PIN set.

My understanding is that the PIN you enter in the App should be the same as the one set on the motor. Bu we actually dont have the motor PIN

 

[szkuba]

So i asked for PIN to Bikee and it is working now. Today afternoon first test rides.

 

[jhoexp]

How close are we to having one of these on the road?

I have tested mine with a temporary battery. It works. Torque sensor calibration procedure is simple, but could be more clearly described in the manual.
Torque sensor seems to work really good, some delay from when you stop pedaling to when power comes down, but I haven't tried to tune it yet. I cannot remember if I had bought the gear sensor too, If I did not I should have...

Display menu looks really tidy (I am used to the eggrider), some problems in the tuning and bike menu with some items not displaying correctly and strange behavior of parameters.
Sounded much louder and grinding than my bbshd, and less powerful (as expected), but my battery lasted 2 slow pulls, was just for a super quick test ride.
I'll take some pictures and have a small report when I finish building the battery.

Bytheway, 48V is what they told me is the max nominal voltage with the 1000W motor (and minimum too, it does not work at 36V), but you can select 14 and 15s in the menus... I asked them what the absolute max working voltage is, but Victor replied that it can go up to 52V (14S?) with the superhero package. I'll call them again to clarify this.
14S is 58.8V fully charged, so I bet it can do at least 60V. Eggrider display cannot go more than 60V, so probably this one (that is the same hardware) has the same limit. Who knows what their controller can do...

 

[neptronix]

What would be telling about the maximum voltage is opening it up and inspecting the caps and FETs on the controller.

15s at 100% state of charge ( 4.2v x 15s = 65 ) is 63v which is the stated maximum limit of most FETs and caps specced for 48v operation.

It's interesting that this option is in the menu, personally i would advise against going the 15S route unless you're willing to charge your battery to 60v average for a safety buffer, until we know what the electrical internals look like.

Personally i would prefer to run an external controller so that i can remove the controller's heat from the motor case and this would free up some thermal headroom to push the motor a bit harder.

 

[neptronix]

Sounded much louder and grinding than my bbshd, and less powerful (as expected), but my battery lasted 2 slow pulls, was just for a super quick test ride.

Damn, i hope it quiets down over time as the gears wear in.

 

[jhoexp]

If it's much louder than my BBSHD that is a showstopper for me. Sounds like it has a metal gear?

I'll have to test it properly. In a few days I should be back where I have the bikes and will take a short video of it working. Honestly I was a bit disappointed with the noise. It isn't loud by any means, but not as quiet as the bbshd. It almost felt as the chain was grinding. Not even so sure of where the noise was coming from, consider I had to stretch the chain and sure using two different type of chains wasn't ideal, but I doubt it was it...

 

[richj8990]

I'll have to test it properly. In a few days I should be back where I have the bikes and will take a short video of it working. Honestly I was a bit disappointed with the noise. It isn't loud by any means, but not as quiet as the bbshd. It almost felt as the chain was grinding. Not even so sure of where the noise was coming from, consider I had to stretch the chain and sure using two different type of chains wasn't ideal, but I doubt it was it...

Well that chain has to go through a lot more tensioners than a Bafang one, so no wonder it would be louder, it has a lot more chores to do before it even gets to the rear cassette.

 

[Golo]

I'm really looking forvard to a test ride video to get a better impression of the noise.

I might have found a solution for the isis bottom bracket for my bike. I hope this axle can be used. If if understand right it gives me isis spline with my existing shimano hollowtech BB.

https://www.lift-mtb.com/en/produit/pedal-axis-isis/

 

[rhauff]

Personally i would prefer to run an external controller so that i can remove the controller's heat from the motor case and this would free up some thermal headroom to push the motor a bit harder.

I believe the external controller is still an option

 

[eggrollspeedway]

I wish the Lightest motor's manual had better quality images. They just distort when you zoom into the manual. Makes it very difficult to identify parts and procedures.

 

[uhmwpolyethylene]

What attracts me to this besides the weight is the claimed solving of torque reduction issues, like supposedly 90nm equivalent with 30nm of output. Is that just hype or is there something to that? I'm attracted to the idea of putting on a lightweight climbing bike or titanium Brompton.Are there other 250-750 midengines that solve this issue? Is it true also that mid engines are often 2x more power efficient as hubs, or is that only uphill or even true

Lightest ebike kit: YOUR BIKE WITH SUPERPOWERS their claims about torque reduction efficiency

 

[eggrollspeedway]

Based on this Facebook post, I believe Bikee sent me a standard mount. Standard Mount | Facebook

Does anyone know if the standard mount changed from its original design? These are the parts sent to me in my kit:
But these are these diagrams that accompany the standard mount on that Facebook post Standard Mount | Facebook and they look different.

 

[richj8990]

What attracts me to this besides the weight is the claimed solving of torque reduction issues, like supposedly 90nm equivalent with 30nm of output. Is that just hype or is there something to that? I'm attracted to the idea of putting on a lightweight climbing bike or titanium Brompton.Are there other 250-750 midengines that solve this issue? Is it true also that mid engines are often 2x more power efficient as hubs, or is that only uphill or even true

Lightest ebike kit: YOUR BIKE WITH SUPERPOWERS their claims about torque reduction efficiency

What I've noticed (and this is a generalization) is that mid-drives have about twice as much torque as the equivalent-rated geared hub motor and about four times as much torque rated watt for watt as a direct drive.

But that does not make them more efficient. I have no idea where that statement originally came from. If you look at some 70-lb direct drive bike with a huge, heavy motor and battery, and then you look at a 50-55 lb mid-drive bike with a smaller, lighter motor and probably 36V battery, someone out there one day thought "Mid-drives must be more efficient". OK...so you can have a lighter bike that generates more torque with a lighter engine and battery. But when all is said and done, my geared hub drive and mid-drive still drain a 17.5 Ah battery after about 30-35 miles. The mid-drive only drains the battery faster because I'm having more fun using more watts at one time. If I could use PAS at 150-250W I could for sure get 35+ miles per charge just like the geared hub drive on a bike that's 5 more lbs (50 lbs vs. 55 lbs).

2-4x as much torque up hills does not mean they are 2-4x more efficient. There is no way I'm going to get twice as much battery range climbing hills all day with the mid-drive compared with the geared hub drive. They will both need about 400-600W to climb decent and they will therefore both drain the battery at roughly the same rate. The real difference is that I can climb 'better' with the mid-drive and not get as tired doing it. But that is not the same as the mid-drive being more efficient; that is simply the wrong term for it. A diesel truck pulling a 53' 18-wheel trailer may be more 'efficient' climbing hills but it's still going to average 6 miles per gallon. Efficient is not exactly the term I'd use for 6 mpg.

If they are claiming 90 Nm of output with a normally 30 Nm motor, then they must be doing some additional 3:1 reduction 'somewhere'. That's why I was saying that this motor needs a dual chain, so that you take the pressure off the cassette chain and don't make it go through a labyrinth of pulleys up front. You let the 2nd drive chain do that and then you can get an external 3:1 reduction. And I don't think 10mm of extra play in the spacing will realistically allow a 2nd chain but maybe someone can make it work.

Lastly, there are 'some' advantages of geared hubs over mid-drives, even climbing. Sometimes a nice, slow, steady hub motor at the right wattage and rpm can be better in certain circumstances climbing than a mid-drive. In some certain circumstances. Sometimes the tortoise can be faster than the hare. I mean really, sometimes a 26" tire can be better than a 27.5" or 29". Not usually, but sometimes.

 

[Slowchris11]

If you want to compare how efficient two drives are, you have to used an identical load on both.
What you do, is just draining both drives at their maximum power. This is quite a normal thing.
If I look at German eMTB tests, when they do the "which bike does the house trail faster" test, the usual Bosch, Shimano etc. drive sucks the battery empty over a very short distance, like 18-30 km or 11-19 miles. These are 25 km/h resticted bikes priced up to 13.000 US$.
The same bike, used on a flat road with just a little leg work, will do more than 5 times the distance without being exhausted.
Because of our laws we can not plant a 1500W hub drive in a legal bike and call it 250W continous power. So hub drives are out of question where I live and only found in low priced bikes.

If you seriously ask me what is more efficient, on a straight road with constant speed the direct driven rear hub could be the better principle. In reality there is more development and more expensive production work, just as higher quality materials in mid drives. So in real world, mixed use, the the mid drive will win.

 

[neptronix]

Mid drive torque is measured by manufacturers at very low RPMs ( usually not specified ), but we can say at least 80rpm.
It cannot be compared to hub motor torque values without finding out what the reduction ratio is between the crank and the selected gears on the bike.

Let's take a simple example of a mid drive at 80rpm producing 90nm torque at 25mph, with a hub motor running in the same condition at 320rpm at the wheel.

320rpm / 80rpm = 4x difference in RPM.
90nm / 4 = the mid drive is producing 22.5nm at the wheel in this selected reduction ratio.

The mid drive has no power advantage in the motor itself. What is has is the advantage of a transmission, in exchange for added gear and chain friction losses.

On relatively flat terrain, a DD will always beat anything in efficiency simply due to the lack of extra mechanical friction that gears produce. It will continuously be close to peak efficiency during cruise.
Inversely, in very hilly terrain, a DD will be much less efficient than a mid drive, because it will run significantly outside of it's efficiency curve; and this also creates major thermal issues. The mid drive motor can be running within the ideal efficiency band of the motor, which negates all of the efficiency loss to friction in this scenario.

Basically the ideal drive mechanism depends on where you are riding this bike, if we are *only* talking about efficiency.
( and not thinking about weight, legal power restrictions, size, etc etc )

 

[jhoexp]

I found the quietest place around here and this is the noise it makes, climbing at 12-14 km/h on a steep hill.
I have put only 20 km on this thing, so it should get better in time, already seemed more quiet than before.

I really like it, feels very natural, like a proper bike. I haven't ridden a legal ebike in a while, so first it felt strange, and the super low gearing amplified the feeling, but now that I have tried it for a few km it reminded me of a levo or any Shimano/Yamaha/Bosch powered ebike.
The torque sensor make it feels much more like a bike than the bbshd, that (at least on my build) feels like this strange bike/super-light dirtbike hybrid.

A few pictures of my baby, with her big sister. Still have to make the final battery but today had so many fault in the shop that decided to f@ck it and go ride it. Notice the 2X 2mm spacers I had to cut (before my cnc controller exploded today ) to make the chainline right. In the end I found a good combination of spacers in the BB and the shaft has no play. Still the freewheel wobbles up and down a bit.







P.S. Almost forgot! It worked @14S! Used a 15s discharged @60V and a warning popped up on the phone (high voltage battery! lol), but it ran no problem. I wish someone dares to try 15S!

 

[rhauff]

Thanks @jhoexp for posting a video of noise, been anxiously awaiting! Do you run a machine shop?
Very nice install, I noticed there is no strap around bottom tube to secure the motor. Do you have ISCG lugs?

 

[jhoexp]

Thanks @jhoexp for posting a video of noise, been anxiously awaiting! Do you run a machine shop?
Very nice install, I noticed there is no strap around bottom tube to secure the motor. Do you have ISCG lugs?

What do you think of the noise? Now I am sure it is making it all the motor alone. The chain was pretty quiet this time, and probably needs to be shorted a bit.

I just have the usual "garage shop" with a small milling machine, cnc router, lathe, etc... No V8 on the bench, like you guys do over there! (just my 250 2t beta trial motor that needs a rebuild!) I don't have the iscg mouting points, just wanted to see if the motor stays there with no straps, it seems solid.

 

[szkuba]

I wish the Lightest motor's manual had better quality images. They just distort when you zoom into the manual. Makes it very difficult to identify parts and procedures. View attachment 338395

Indeed those pictures are very low resolution. BTW the English manual is now at Rev.10 with much improved bottom bracket information and motor chainline calculation .

 

[jhoexp]

Oh no! This motor has a very unpleasant noise. Damn. @jhoexp is their no way to get any more chain wrap than that?

Yes, you can use the rear chain guide, it was in the kit. I'll put it on today with the 34t front chainring.

 

[jhoexp]

Indeed those pictures are very low resolution. BTW the English manual is now at Rev.10 with much improved bottom bracket information and motor chainline calculation .

The manual format does not make any sense, there is no way you can print it properly as booklet or any format. They should redo it in A4. Pictures are ridiculously small and their layout is terrible.

All the new instructions on the bb are a bit confusing, and by my experience on the bsa 68/73mm bb, what they show is not really correct.
Still their Italian website does not show the download page, it's only there in the american version.

 

[Golo]

I found the quietest place around here and this is the noise it makes, climbing at 12-14 km/h on a steep hill.
I have put only 20 km on this thing, so it should get better in time, already seemed more quiet than before.

I really like it, feels very natural, like a proper bike. I haven't ridden a legal ebike in a while, so first it felt strange, and the super low gearing amplified the feeling, but now that I have tried it for a few km it reminded me of a levo or any Shimano/Yamaha/Bosch powered ebike.
The torque sensor make it feels much more like a bike than the bbshd, that (at least on my build) feels like this strange bike/super-light dirtbike hybrid.

A few pictures of my baby, with her big sister. Still have to make the final battery but today had so many fault in the shop that decided to f@ck it and go ride it. Notice the 2X 2mm spacers I had to cut (before my cnc controller exploded today ) to make the chainline right. In the end I found a good combination of spacers in the BB and the shaft has no play. Still the freewheel wobbles up and down a bit.
View attachment 338496

View attachment 338497
View attachment 338498

View attachment 338500

P.S. Almost forgot! It worked @14S! Used a 15s discharged @60V and a warning popped up on the phone (high voltage battery! lol), but it ran no problem. I wish someone dares to try 15S!

It would have been interesting if you made a video of the bbshd bike in the same way you did with the lighest. As a comparison since the bbshd is known for beeing very silent.