Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Doctorbass]

I just finished compiling all these data from various Zero that i got acces to the controller and grabed the data using my IXXAT programming interface

I also added a PDF that i made for better view

Now for you guys!! 

Doc

[protomech]

Those are the requested values or the delivered values at the motor output shaft?

[Doctorbass]

Those are the requested  limit value.
(not measured)
Doc

[Doug S]

Excellent data, Doc. The SR rolls off surprisingly early, considering how good its rollon performance is on the freeway.

[GdB]

After spinning the rear wheel turning left from a stop on my first ride, and recovering OK, I was surprised by the torque compared to ICE bikes I have ridden.

So I put your data together with…    Looks like more rear wheel torque than most ICE bikes up to 50, more than a 600 ICE bike up to 100 km/h, after that equal up to 160.  At very low speed turns from a stop I am use to being able to ask for full power without spinning the wheel.  These bikes really need traction control!

What's up with the 30/128t gearing?  My 2014 S has 28/132t gearing.  So I probably need to drop the Zero curve a little.

Also I was thinking about upgrading to the higher speed gearing, but the torque will drop a lot.

[domingo3]

Does this refute the theory that torque is limited at low speed/RPM to prevent wheelie/ loss of traction?

[grmarks]

After spinning the rear wheel turning left from a stop on my first ride, and recovering OK, I was surprised by the torque compared to ICE bikes I have ridden.
At very low speed turns from a stop I am use to being able to ask for full power without spinning the wheel.  These bikes really need traction control!

Having ridden dirt bikes most of my life, I find the SR very easy to ride and control its power. I don't need traction control at all. Just don't turn the throttle on full, easy! You could/would never use full throttle on a big dirt bike from a standing start. You use throttle control.
I would rather they spend there R&D budget on other things - like a variable regen lever where the clutch lever normally goes (or rear brake on a scooter). You could have a much higher maximum regen setting with this.
Or a reverse switch, or a sports bike type fairing.

[Nuts n Volts]

Does this refute the theory that torque is limited at low speed/RPM to prevent wheelie/ loss of traction?

It has been stated multiple times that the torque is not limited by Zero on these bikes at low speed.  Data in this thread proves that you have full torque as well.


Sent from my iPhone using Tapatalk

[protomech]

After spinning the rear wheel turning left from a stop on my first ride, and recovering OK, I was surprised by the torque compared to ICE bikes I have ridden.
At very low speed turns from a stop I am use to being able to ask for full power without spinning the wheel.  These bikes really need traction control!

Having ridden dirt bikes most of my life, I find the SR very easy to ride and control its power. I don't need traction control at all. Just don't turn the throttle on full, easy! You could/would never use full throttle on a big dirt bike from a standing start. You use throttle control.
I would rather they spend there R&D budget on other things - like a variable regen lever where the clutch lever normally goes (or rear brake on a scooter). You could have a much higher maximum regen setting with this.
Or a reverse switch, or a sports bike type fairing.

That's fine, but it's easy enough to hit a patch of sand or scree in a corner and have even a partial throttle (accelerator) opening cause a rapid wheel spin up and loss of control.

Zero does have to pick and choose what to develop, and it's certainly not free to implement a an effective throttle control system.

[Kocho]

Traction and stability control is for when you do *not* have control. As mentioned, during certain unexpected loss of traction, no matter how many years of dirt bike or other experience one has, one can't react fast enough to regain control.

I've been driving for 20+ years before it happened to me on a road in my car - lost control at a curve due to unexpected loss of traction. If the vehicle had stability control, it would have been a non-event, but it did not: I spun out of the road and had an accident (minor, but annoying). I hit not one, not two, but three trees before the car stopped. Dinged it on three sides as it was spinning. On a bike the same situation would have resulted in broken bones or worse.   

I could have regained control of the car in that situation, but I ran out of time - there was oncoming traffic and I *chose* to go off the road rather than risk a head-on collision while regaining control. That much time I had. With stability control, the car would not have spun out in the first place, as I was not going that fast. And yes, a better driver than me might have possibly regained control fast enough to stay on the road, but that's beside the point - not everyone is a professional drift driver...

Traction control costs something. But the control modules are becoming mainstream, so I would think not prohibitively expensive any more. It's a matter of tuning, not invention these days - just like with the ABS, which we already got from Zero. Add traction/stability control as an option and see if people buy it or not. These things are standard on cars for a good reason - it works.
 

Having ridden dirt bikes most of my life, I find the SR very easy to ride and control its power. I don't need traction control at all. Just don't turn the throttle on full, easy! You could/would never use full throttle on a big dirt bike from a standing start. You use throttle control.
I would rather they spend there R&D budget on other things - like a variable regen lever where the clutch lever normally goes (or rear brake on a scooter). You could have a much higher maximum regen setting with this.
Or a reverse switch, or a sports bike type fairing.

[GdB]

The low speed torque limiting is everyone is debating is probably a programmed lag in throttle response which is there to avoid a too jerky feel.  The motor could easily change from zero to full torque in milli seconds, which would be harder to control, very jerky and damaging to the drive train.

I suspect the flywheel mass (motor rotational inertia) may be too small to reduce wheel spin.  In multi speed gearboxes, the flywheel effect is most important in 1st and 2nd gear.  The Zero's gear ratio is more like a 3rd or 4th gear.


The traction control parts (lean angle, gyro's etc) are off the shelf, so it's just a matter of integrating it with the ECU.  Since ABS is now standard, the wheel speed sensors are already there.
http://www.sportrider.com/sportbike-news/bosch-introduces-motorcycle-stability-control

[Fivespeed302]

After spinning the rear wheel turning left from a stop on my first ride....
These bikes really need traction control!

Tell me about it.  I have a nice scar that agrees with you.