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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: geijuutsuka on July 19, 2020, 10:01:44 AM

Title: Significant range differences in pair of SR’s
Post by: geijuutsuka on July 19, 2020, 10:01:44 AM
Both 14.4 charge tanks.  Belt tensions set by dealership according to the newer (25kg-76kg) standard.

Bike One: 3000miles, belt tension 35kg, 2018 SR
Rider One: 5’4”, 130lbs

Bike Two: 500miles, belt tension 47kg, 2019 SR
Rider Two: 5’10, 150lbs

All other details are identical.

We can start riding at the same time, in eco mode, at the same speed, hitting most REGEN spots at the same time, and the 2018 35kg belt will ALWAYS end up with 10-15% more in the tank after a 80+mile ride.  Sometimes i would tuck for a few miles to try and close the gap, but it didnt seem to help.

How much does height and weight factor in?  What about belt tension?  The 2019 rear wheel/belt is noticeably more noisy from the extra 12kg of tension between them, could this be recorded as drag?  Ive also considered brake drag as both of our bikes have it on both wheels (dealership said brake drag is normal??)  Both discs hiss on both bikes fairly equally so im at a bit of a loss. 

Any data is appreciated, cheers!

Title: Re: Significant range differences in pair of SR’s
Post by: TheRan on July 19, 2020, 10:09:00 AM
Others may disagree but I wouldn't consider that a significant difference. The smaller and lighter rider is going to be more aerodynamic which can make a big difference and they'll require less energy to get up to speed (assuming both riders are even accelerating at the same rate). Are tyre pressures also the same? That's another factor that can have a considerable affect on range.
Title: Re: Significant range differences in pair of SR’s
Post by: geijuutsuka on July 19, 2020, 10:16:54 AM
Tire pressure on both bikes is 32psi front, 34psi rear
Title: Re: Significant range differences in pair of SR’s
Post by: Crissa on July 19, 2020, 10:43:07 AM
The size of the rider I think could have a significant effect.  And then riding style on top of that...

-Crissa
Title: Re: Significant range differences in pair of SR’s
Post by: DonTom on July 19, 2020, 12:16:41 PM
We can start riding at the same time, in eco mode, at the same speed, hitting most REGEN spots at the same time, and the 2018 35kg belt will ALWAYS end up with 10-15% more in the tank after a 80+mile ride. 
10 to 15% More what?  Battery voltage or % SOC?

What you will probably find if you're using the SOC is that the bike that hits 0% SOC will have around the same range left as the other that still shows 15% SOC.

-Don-  Reno, NV
Title: Re: Significant range differences in pair of SR’s
Post by: geijuutsuka on July 19, 2020, 12:39:19 PM
10-15% more on state of charge.  I’m new to zeros so im trying to keep up on the nitty gritty numbers game, but i’m not sure how your example works out, can you explain what you mean by 0 and 15% being the same? 
Title: Re: Significant range differences in pair of SR’s
Post by: DonTom on July 19, 2020, 01:39:40 PM
10-15% more on state of charge.  I’m new to zeros so im trying to keep up on the nitty gritty numbers game, but i’m not sure how your example works out, can you explain what you mean by 0 and 15% being the same?
Zeros are well known for showing different SOC indications when the battery voltage is exactly the same between two bikes, even if the same year and model.

You really do not know how much range you have left until it won't run anymore. Some Zeros will run at 0 SOC for quite a while and another may go dead at around 5 % SOC.

Checking the battery voltage and comparing it after the same ride will be more accurate. You really shouldn't use the SOC gauge  for comparing anything.

Also, some firmware updates  change how the SOC reads. Be sure both bikes are using the same FW as that could get the SOC closer between the two bikes. But even then, don't expect them to read exactly the same under the same distance of riding.

-Don-  Reno, NV
Title: Re: Significant range differences in pair of SR’s
Post by: TheRan on July 19, 2020, 06:23:02 PM
I think the reason why some bikes will run at 0% and some will die at 5% is because whether the bike will run or not is not tied directly to the SoC reading but rather the voltage of the battery, not the static voltage (what the SoC is based off) but rather the voltage under load. How much the voltage sags under load can depend on many factors, so while the 5% bike might technically have a higher static voltage it may end up being lower once the bike actually tries to move.
Title: Re: Significant range differences in pair of SR’s
Post by: dittoalex on July 19, 2020, 08:11:45 PM
Tire pressure at 32F/34R is too low, I'd notice at least 5% range loss from my 36F/38R.
Title: Re: Significant range differences in pair of SR’s
Post by: princec on July 19, 2020, 08:24:24 PM
Just swap bikes and riders to see what effect that has.

Cas :)
Title: Re: Significant range differences in pair of SR’s
Post by: nevetsyad on July 19, 2020, 08:34:56 PM
Swap riders, repeat and find out for sure if it's a rider issue? (style, size, mass, etc.)
Title: Re: Significant range differences in pair of SR’s
Post by: nevetsyad on July 19, 2020, 08:35:34 PM
Guess I should have refreshed before posting :p

Just swap bikes and riders to see what effect that has.

Cas :)
Title: Re: Significant range differences in pair of SR’s
Post by: nnelson65 on July 21, 2020, 12:17:47 AM
I second this suggestion.


Swap riders, repeat and find out for sure if it's a rider issue? (style, size, mass, etc.)
Title: Re: Significant range differences in pair of SR’s
Post by: vinceherman on July 21, 2020, 01:15:36 AM
More tests.
Swap riders as others have suggested.
Have the taller rider tuck to get the same frontal area.
Title: Re: Significant range differences in pair of SR’s
Post by: BrianTRice@gmail.com on July 21, 2020, 04:36:46 AM
This is maybe an ideal case to swap riders.

One thing is that a less smooth handling of the throttle can waste more power. I use a throttle lock to avoid some loss there.

Once you’ve tried that, a windscreen will mitigate the effects of rider size on drag and power consumption.
Title: Re: Significant range differences in pair of SR’s
Post by: SBK74 on July 22, 2020, 06:27:03 PM
Tyres and tyre pressure comparable? Brake drag? If the belt tension is considered of influence, one should measure a temperature difference of the belt with an IR thermometer.
Title: Re: Significant range differences in pair of SR’s
Post by: KuRi on July 23, 2020, 06:22:47 PM
Acceleration??? That's what kill the battery the most :D
Title: Re: Significant range differences in pair of SR’s
Post by: AutoE on August 01, 2020, 03:46:01 AM
Swap riders if "problem" remains post MBB and BMS logs from both. What FW is on both (MBB and BMS). We've seen 30% and greater range loss with "FW upgrades".