Luna Z1 - First impressions

[JRA]

I just happen to have my rear wheel off my Z1 and it sure looks like that is the proper hanger to me.

Edit: Reason I had the wheel off is to swap it out with another. Kudos to LUNA for specing a steel HG driver.

Edit 2: The other wheels and tires fresh off Brown Santa's sleigh. One from Cali and the other from ID.. Ordered just before the holiday....ended up on the same truck.

 

[Jeebuspwnz]

I had a loud, super obnoxious creaking headset. Im betting others are having this problem - headset creaks like crazy, tightening compression, headset and handlebar connections doesn't make a difference. Creaks are common with Carbon but this was ridiculous. Finally tipped the bike over and dribbled a little chain lube where headset meets the frame (at the bottom of the headset) and VOILA, silence.

I noticed some play that doesn't seem to be related to how tight it is. Not very noisy tho.

 

[Jeebuspwnz]

Did anyone ever determine if these are the correct hangars for the Z1? I bent mine this weekend and its only a matter of time till I break one, would like to get a pare to have on hand.

I just ordered. I'll let you know in a few weeks.

 

[rtp]

I had a loud, super obnoxious creaking headset. Im betting others are having this problem - headset creaks like crazy, tightening compression, headset and handlebar connections doesn't make a difference. Creaks are common with Carbon but this was ridiculous. Finally tipped the bike over and dribbled a little chain lube where headset meets the frame (at the bottom of the headset) and VOILA, silence.

Sounds like no grease on bearings in this case?
On my X2 I’ve got one persistent but sporadic and not loud creak - always there meaning every ride, not super loud but there. Might be time to pull it apart, but will see if a few drops makes it stop first…

 

[rtp]

I just happen to have my rear wheel off my Z1 and it sure looks like that is the proper hanger to me.

Edit: Reason I had the wheel off is to swap it out with another. Kudos to LUNA for specing a steel HG driver.

Edit 2: The other wheels and tires fresh off Brown Santa's sleigh. One from Cali and the other from ID.. Ordered just before the holiday....ended up on the same truck.

Pics NOT in boxes are sooo much better (hint)

 

[Jeffr]

Sounds like no grease on bearings in this case?
On my X2 I’ve got one persistent but sporadic and not loud creak - always there meaning every ride, not super loud but there. Might be time to pull it apart, but will see if a few drops makes it stop first…

I think it would be unlikely that the bearings had no grease. More likely the seat between the metal headset race and the carbon Frame had a minute amount of rubbing, creating the creaking sound. When carbon creaks the frame magnifies the sound. A drop of oil stop the rubbing.

 

[Jeffr]

Pics NOT in boxes are sooo much better (hint)

I swapped out wheels with my other bike, 40 mm tubules Maxxis Minion DHF and DHR. Grabs hold and doesn't let go! What amazing grip. The Rekons are adequate general purpose tires, but for single track grip the Minions are in a class of their own. The Apollo is spec'd for minions, which cost double of Rekons.

 

[Jeebuspwnz]

I think it would be unlikely that the bearings had no grease. More likely the seat between the metal headset race and the carbon Frame had a minute amount of rubbing, creating the creaking sound. When carbon creaks the frame magnifies the sound. A drop of oil stop the rubbing.

I just pulled the top and bottom bearings on mine. Reseated everything. My play is finally gone.

 

[JRA]

I swapped out wheels with my other bike, 40 mm tubules Maxxis Minion DHF and DHR. Grabs hold and doesn't let go! What amazing grip. The Rekons are adequate general purpose tires, but for single track grip the Minions are in a class of their own. The Apollo is spec'd for minions, which cost double of Rekons.

I have been having the same success with the WTB Vigilante, can't break them loose on either end. In concert with the rear travel grip is eons better on the Z1 than anything I have had in the past.

Got things out of the box and installed. There was a bit of a hiccup in that the lowers on the stock Yari are only good for b+ boost and I wanted to mullet the bike. With some red neck engineering and some past experience I was able to get it all back together after some effort but no swear words at least.

Best thing was that it is a warmish day here and sun is out. I am off the bike for a few more days doctors orders anyway so it's good that this is taking place now anyway....

Got the laptop for the tune finally and will do that tonight.

 

[JRA]

Now that those of us that have lived with the Z1 for awhile just checking in to see if anyone else is not all that satisfied with the battery performance? I was reluctant actually to go here with this but after reaching out to LUNA about it felt that going forward they weren't going to be much help.

I've got over 300 miles now on the bike and done several modifications along the way. Unfortunately still not able to get JonA's frey tune onboard but I really don't think it will have much bearing on what I am most concerned with.

I have been doing rides around the hood mostly using levels 1-3 in the 5 level mode. Basically 1 in the woods and tight sections, 2 on level and logging roads and 3 on the ups but not always. Ride lengths have been a bit under 20 miles of varied terrain with 2k vert average gain. I have been cutting out @ 45.5v even using mode 1 and active pedaling. I can squeeze another V out of it by off/onning the display but basically from the first cut out it is lights out from there and you had better be close to home. Hooking up to the charger I get a reading of 44.5v on the charger readout. Upon charging from there the Ah returned into the battery is around 14ah which translates into 672wh. BTW to determine this I use a Grin Satiator charger which is very accurate in regards to reading voltage at time of charge and how many Ah's it charges. From that I determined awhile ago that my display reads .5v low also and allow for that while riding.

LVC as per LUNA is 42v and I do realize that voltage sag is a thing and have been living with it and managing it for a long time now but I feel that it is more noticeable with the Z1 than other bikes I have had including 1000w hub motors. Cutting out 4 volts above the LVC even using low mode assist just is not the performance I am looking for. Maybe when I finally get the tune installed it will help some but I don't see how it will affect the cut out from happening as it stands?

So I guess my question is to the other Z1 owners on here is am I alone in my findings or is this a standard feature?

 

[scrambler]

Just as data points on a 14S pack, the difference between 45V and 42V corresponds to a cell voltage difference of 3.2V vs 3.0V (the cutoff voltage)
Looking at discharge curves for cells like the Panasonic GA for example, this is the voltage differential between pulling 1 Amp per cell (4A on a 4P pack @ 45V=> 180W) vs pulling 5 Amp per cell (20A on a 4P pack @ 42V=> 840W).
So if you are pulling 180W and reach 45V then pull 840W, you can cross the cutoff voltage.

If you are not spiking in power, then it would be worth verifying the cutoff voltage in the controller, but also in the BMS as either of these could cause the cutoff, and they don't necessarily have the same settings.
Having the cutoff at 3.2V is a good way to increase the pack longevity

 

[JRA]

i understand the math but my experience with getting home on low voltage by reducing assist and upping human input has never been so touchy. Granted I switched to 2170 cell batteries 3 yrs. ago and they do seem to have less drastic sag at lower voltages but you still have to treat them lightly.

The M620 is a big motor with lots of copper in it and in relation to my other motors is on another scale. So even using level 1 it draws more amps. So my question is if there is an answer to a battery that will perform better at low voltage? I am thinking that a 5A 2170 cell would be at least a step in the right direction and also going to a 15S pack so that even thought the cut off is higher so is the voltage in the lower range. I have both 14 and 15S batteries and although I don't see a huge difference in performance I have never really regarded the low voltage performance because I haven't had the issues that this bike displays.

I am not interested in more power but would like more range ability. With a 15S 15Ah/780wh battery on my 1000w capable hub bikes I can get up to 40 miles at a satisfying speed. If I could pump up the range on this bike from 20 to 30 I would be happy enough.

Side note is that yesterday I was riding with my friend who has a 2020 Giant FS with the 620wh battery and we both ran out pretty much at the same time. So wh per wh we were pretty close to the same usage riding together at the same speed.

 

[scrambler]

More range will mean more Wh no matter what, so the first question is are there batteries with more capacity that can fit?
Then you can wonder about the pack configuration and the cells.

If you are pulling a lot of Amps with the motor, then having a pack that has the ability to provide high amp draw will help a bit with the Cell voltage drop.
That can either be achieved by a Pack using cells that have high amp draw or a pack configuration that has more cells in parallel.
Cells that have high Amp draw (like the Sony VTC6) have a lower capacity, so what you gain on one side you loose on the other...

In that regard, for a powerful motor like the Ultra, and if using 18650 cells, I think a 14S - 5P could actually be better, but it is 70 cells so 10 more than a 15S - 4P....

 

[scrambler]

And using 201700 or 21700 cells would help a lot in that regard.
Cells like the NCR20700B have 4.25Ah capacity and a 20A continuous discharge.
a 14S - 4P of these would be 857 Wh with a possible 4000W continuous draw, which means using an Ultra motor, you would be in the low usage area of the discharge.
So a 15S - 4P would also make sense with 918Wh and still a very comfortable margin for power draw..

 

[JRA]

I have Hailong case 2170 cell batteries in 12/15 and 17.5 ah configs and all of them will come close to using their maximum relative wh's as shown on my charger. The fact that the Z1 battery is supplied as an 840wh battery and only supplys 680 +/- real world does not coincide with my experiences so that is why I am a bit flumoxed I guess. I am no engineer and only a seat of the pants type so take that into account.

I suppose that once I can get my window's computer act together and get into the programming I can lower level 1's draw or even make 0 a very low draw as I never use it for anything else. That way I may be able to at least get 300w out of it to offset the weight of the bike which is no fun to ride without power due to its heft if it even smells an uphill. Still goes fine on the flats and downs though.

 

[scrambler]

Do we know what exact cells and configuration Z1 battery uses, and do you have access to the BMS settings?

 

[JRA]

No and they are in a pretty stout casing but I'm sure with a little work could be cracked. The only info available from Luna is this:

Which doesn't say how many mah the cells are and their math is off by 10wh's....

I am not going to tear apart this battery but am going to take measurements of the cavity and see how many 2170 cell may fit in there at some point here in the not too distant future. Quite frankly I would be happy with a smaller 20 mile battery x 2. Most of my hood rides are up to 20 miles and for longer rides carrying an extra would not be a problem. And hopefully the new battery would be even a little lighter?

One of the reasons I resisted an integrated battery bike was just for this very reason....

 

[scrambler]

With 18650 cells, 48V x 17.5Ah would be 13S -5 P of 3.5Ah cells
Vendors measure the Capacity between 4.2V and 2.5V, so with a minimum cutoff of 3V, this means the real capacity is actually lower.

If these are the LG MJ1 cells, below are the discharge curves

Test of LG 18650 MJ1 3500mAh (Green)

They tell us that at 3V cutoff, the cell capacity is between 2.9Ah at 5Amp discharge or 1200W and 3.1 Ah at 2A disch or 500W
2.9Ah is a 697Wh and 3.1Ah is 746Wh

 

[Jeffr]

Now that those of us that have lived with the Z1 for awhile just checking in to see if anyone else is not all that satisfied with the battery performance? I was reluctant actually to go here with this but after reaching out to LUNA about it felt that going forward they weren't going to be much help.

I've got over 300 miles now on the bike and done several modifications along the way. Unfortunately still not able to get JonA's frey tune onboard but I really don't think it will have much bearing on what I am most concerned with.

I have been doing rides around the hood mostly using levels 1-3 in the 5 level mode. Basically 1 in the woods and tight sections, 2 on level and logging roads and 3 on the ups but not always. Ride lengths have been a bit under 20 miles of varied terrain with 2k vert average gain. I have been cutting out @ 45.5v even using mode 1 and active pedaling. I can squeeze another V out of it by off/onning the display but basically from the first cut out it is lights out from there and you had better be close to home. Hooking up to the charger I get a reading of 44.5v on the charger readout. Upon charging from there the Ah returned into the battery is around 14ah which translates into 672wh. BTW to determine this I use a Grin Satiator charger which is very accurate in regards to reading voltage at time of charge and how many Ah's it charges. From that I determined awhile ago that my display reads .5v low also and allow for that while riding.

LVC as per LUNA is 42v and I do realize that voltage sag is a thing and have been living with it and managing it for a long time now but I feel that it is more noticeable with the Z1 than other bikes I have had including 1000w hub motors. Cutting out 4 volts above the LVC even using low mode assist just is not the performance I am looking for. Maybe when I finally get the tune installed it will help some but I don't see how it will affect the cut out from happening as it stands?

So I guess my question is to the other Z1 owners on here is am I alone in my findings or is this a standard feature?

This is a real issue. I performed JonA's Frey tune and it does dramatically reduce the cadence assist (pedal assist) in favor or torque assist, and feels much more natural. It also lowers the LVC to 38V. so you get a bit more range out of the battery. However Once the battery gets to about 45 volts it goes into "limp" mode capping power to 400 watts or so, so the sag stops happening; power output is so anemic that it barely overcomes the weight of the bike.
Even with the improved efficiency and lowered LVC, I still only managed 18.6 miles and 2200 vertical feet before the power output was so low I had to terminate the ride. . My friend with a Levo running it continuously in Turbo assist still had 40% battery remaining when I was at 41v dipping into 40.
So either the Bafang is much less efficient, or the battery is not delivering rated power or I suspect a bit of both. A second battery, 48v 15A same configuration for the Dengfu E10 is available from AliExpress for 360 (+ tax) including shipping. I have ordered one to carry in a back pack for longer rides.
I must say I am disappointed in the lack of range of the Z1. With all the software adjustments, Ive been able to increase range about 40%, but still fall short of 20 miles.

 

[Nebakanezzar]

Dont know if this is any help at all, but when i had my Luna Apollo, Same Bafang Ultra motor but with a 52v 1100wh battery. i was getting over 30 miles per charge, and im a heavy load...well, it was 30 miles between charge over several rides. the battery did exhibit the same 'sag' described above as soon as i fell below 20%