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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: kensiko on February 26, 2014, 04:28:14 AM

Title: Speed stability at constant speed
Post by: kensiko on February 26, 2014, 04:28:14 AM
Hello,

I'm late to post this, but when I purchased my Zero last autumn, I quickly discovered that I had the feeling of not going at constant speed when keeping the throttle at the same position.

Has anyone noticed this on their Zero? It might also be a small issue with my throttle pot or it's just too sensible so that any slight movement of my hand will change the speed.

It's not a big issue it's just a concern.
Title: Re: Speed stability at constant speed
Post by: Richard230 on February 26, 2014, 04:42:11 AM
I haven't noticed that with my 2014 S.  However, many IC motorcycles with fuel injection systems do tend to "hunt" (due to lean fueling) while trying to hold a steady speed.  But nothing like the old two-stroke motorcycles used to do.   ::)  I loved a two stroke engine under acceleration, but hated them when you backed off the throttle and tried to run a steady speed that did not place the engine under a load.

So, I guess what I am saying is that all of the electric motorcycles that I have owned have provide a much smoother and steady throttle application than I am used to since IC emission regulations hit the scene. 
Title: Re: Speed stability at constant speed
Post by: spelunker on February 26, 2014, 05:02:44 AM
I've had my 2013 S for about a year. I got it new and just turned over 14,000 miles on it on the way to work this morning.  I too, have noticed this phenomenon.  It's oddly comforting to know it's not just me!  For me, I'm not overly concerned about it.  My bike is on the recall list, so I hope having my firmware updated takes care of it.  My bike has never quit running, so it's just kind of a nuisance.
Title: Re: Speed stability at constant speed
Post by: oobflyer on February 26, 2014, 05:56:03 AM
Is the speedometer fluctuating?
I haven't noticed this on my 2012 ZF9.

The speedometer runs a bit 'slow' however. When my speedometer reads 75 MPH, my GPS says I'm going 70 MPH.
Title: Re: Speed stability at constant speed
Post by: BrianTRice@gmail.com on February 26, 2014, 06:13:53 AM
The speedometer runs a bit 'slow' however. When my speedometer reads 75 MPH, my GPS says I'm going 70 MPH.

Motorcycle speedometers traditionally have a built in inaccuracy, to appear to discourage motorcyclists from speeding.

http://www.popularmechanics.com/cars/how-to/4260708 (http://www.popularmechanics.com/cars/how-to/4260708)
Title: Re: Speed stability at constant speed
Post by: LiveandLetDrive on February 26, 2014, 06:33:35 AM
Was this flat ground with no wind, etc?  I'm constantly adjusting the throttle by minute degrees whether it be gas or electric just responding to the road and wind.  Nothing drastic but there's a reason cruise-control in cars doesn't just lock the pedal in place.


Agreed my speedo is optimistic, even worse now that I've gone to a smaller rear tire.
Title: Re: Speed stability at constant speed
Post by: Richard230 on February 26, 2014, 07:28:11 AM
My 2012 S had a speedometer that was about 8% fast.  (A cheap way to increase the bike's speed.)  However, my 2014 S has a speedometer that seems to be right on the money.  I do appreciate accuracy.   :)
Title: Re: Speed stability at constant speed
Post by: Burton on February 26, 2014, 08:31:12 AM
The speedometer runs a bit 'slow' however. When my speedometer reads 75 MPH, my GPS says I'm going 70 MPH.

Motorcycle speedometers traditionally have a built in inaccuracy, to appear to discourage motorcyclists from speeding.

http://www.popularmechanics.com/cars/how-to/4260708 (http://www.popularmechanics.com/cars/how-to/4260708)

I was told all foreign cars and bikes sold in the US have inaccuracies because they get fined if they are over the speed indicated. Most, from what I recall, put in a 5% inaccuracy. For me this means at 80mph indicated I am really going 75.
Title: Re: Speed stability at constant speed
Post by: WindRider on February 26, 2014, 10:24:36 AM
In regards to speed stability on Zero Motorcycles, I rode a 2012 Zero DS last season and after about 6K miles I started to experience this.   There was a recall for controller firmware and I mentioned the speed control stability issues to the tech.   After the firmware upgrades he checked out all of the servo performance with the motor and said that there was some encoder drift.   He calibrated the encoder after the upgrades.

After that the speed control instability was completely gone.   Throttle response was perfect and very stable.   Something to check with your dealer if you have that option.   
Title: Re: Speed stability at constant speed
Post by: Le Z Turbo on February 26, 2014, 02:13:51 PM
I sometimes feel this instability also, on my 2013 DS and mainly at low throttle positions. No possibility of reprogramming anything at my dealer here in France, he has no programming tools !!!
Laurent
Title: Re: Speed stability at constant speed
Post by: benswing on February 26, 2014, 06:45:56 PM
My 2012 Zero S ZF9 is rock solid in terms of speed.  Power output is completely consistent.
Title: Re: Speed stability at constant speed
Post by: NoiseBoy on February 26, 2014, 07:19:30 PM
My 2012 Zero S ZF9 is rock solid in terms of speed.  Power output is completely consistent.

+1 its very refreshing after riding an ICE.
Title: Re: Speed stability at constant speed
Post by: dkw12002 on February 26, 2014, 07:26:47 PM
I notice this on a fully charged battery only.
Title: Re: Speed stability at constant speed
Post by: Justin Andrews on February 26, 2014, 10:29:04 PM
My 2012 Zero S ZF9 is rock solid in terms of speed.  Power output is completely consistent.

Agreed, the only time my own Zero S ZF9 started to get sluggish and refused to accelerate past 50mph was when I had gone deeply into the reserve after the last bar had dissapeared.
Title: Re: Speed stability at constant speed
Post by: kensiko on February 27, 2014, 03:29:32 AM
In regards to speed stability on Zero Motorcycles, I rode a 2012 Zero DS last season and after about 6K miles I started to experience this.   There was a recall for controller firmware and I mentioned the speed control stability issues to the tech.   After the firmware upgrades he checked out all of the servo performance with the motor and said that there was some encoder drift.   He calibrated the encoder after the upgrades.

After that the speed control instability was completely gone.   Throttle response was perfect and very stable.   Something to check with your dealer if you have that option.

Thanks for the input, I will check with them. I just hope they won't keep it for weeks.
Title: Re: Speed stability at constant speed
Post by: kensiko on February 27, 2014, 03:33:53 AM
WinRider, did you get more range with the correction? Or you have the same?
Title: Re: Speed stability at constant speed
Post by: WindRider on February 27, 2014, 03:56:44 AM
WinRider, did you get more range with the correction? Or you have the same?

I did not ride it much for range after that last update before I sold it.   But I do remember on the last ride it seemed to go forever so it may have helped with range as well but I can not say it was scientifically proven.
Title: Re: Speed stability at constant speed
Post by: trikester on February 27, 2014, 11:28:57 AM
I noticed the "hunting" when trying to hold a constant speed on level pavement with my 2010 DS. I have not seen it with either my 2012 DS or 2013 FX. I attribute that to the later bikes being a completely different motor and controller system.

I had forgotten about this until I recently rode my 2010 after more than two years of not riding it. It was annoying. I also had forgotten how much better the newer Zero bikes handle. The geometry has improved.

Trikester
Title: Re: Speed stability at constant speed
Post by: kensiko on February 28, 2014, 12:56:57 AM
Thanks for the input.

I called my local dealer and informed him of the issue. They will discuss with Zero about how to check and calibrate the encoder. If everything is OK with them, I will have my bike checked at the same time than for the recall, which they don't have the tools yet.
Title: Re: Speed stability at constant speed
Post by: nicktulloh on February 28, 2014, 01:17:30 AM
Speedometer inaccuracy is also an issue with mileage-based warranties. If your speedo is 5% optimistic, you're getting to the end of your warranty 5% early.
Title: Re: Speed stability at constant speed
Post by: Crawling Finn on March 02, 2014, 05:13:57 PM
My bike is getting worse in constant speed. It has been noticeable only for last couple of thousand miles or the 4K covered. I have been thinking it might have been water getting into connectors as I haven't really had a dry ride since October. Spraying everything with ACF-50 has reduced weird behaviour of the dash with no effect to hunting. Good to hear that I'm not alone. Would be great have dealer to go to. The last one in the UK ceased trading end of December so I seem to be well stuck with what I've got.
Title: Re: Speed stability at constant speed
Post by: BrianTRice@gmail.com on March 04, 2014, 12:07:33 AM
Speedometer inaccuracy is also an issue with mileage-based warranties. If your speedo is 5% optimistic, you're getting to the end of your warranty 5% early.
This is a good point, but not true on the bikes I've ridden. Often the odometer is driven from a much more accurate sensing mechanism than the speedometer.
Title: Re: Speed stability at constant speed
Post by: Richard230 on March 04, 2014, 03:50:46 AM
Speedometer inaccuracy is also an issue with mileage-based warranties. If your speedo is 5% optimistic, you're getting to the end of your warranty 5% early.
This is a good point, but not true on the bikes I've ridden. Often the odometer is driven from a much more accurate sensing mechanism than the speedometer.
 

I agree. Both of my BMW's have 8% fast speedometers, but the odometers seem quite accurate when measured against highway mile markers.  The trip meters are a little goofy though and don't match up with the odometer reading exactly.   ???
Title: Re: Speed stability at constant speed
Post by: kensiko on April 19, 2014, 07:27:30 AM
Problem disappeared with the firmware update! The dealer told me that there was some type of calibration to do. That might have been the encoder calibration.
Title: Re: Speed stability at constant speed
Post by: Richard230 on April 19, 2014, 08:53:23 PM
Speaking of speed calibration: yesterday I found a level piece of freeway and checked my instrument display (with my glasses on) and noticed that 60 mph shows 3850 rpm on my 2014 S.  Also, I was getting 85 watts per mile while holding my speed at a steady 60 mph on level ground with no wind.  I checked my speedometer against one of those radar speed check signs and an indicated 60 mph is an actual 59 mph.  That all sounds good to me.