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[BSDThw]

Nice Tire!

good info, I had never believed a 120/90 will fit so easy

[nicktulloh]

Ordered the Avons today. Can't wait. Anyone want a set of stock knobblies cheap? <400 miles.

[WindRider]

I really like how the new tire grips in the loose stuff but there is a problem:   I now have some vibration and motor unsmoothness at certain speeds.   It is most noticeable at around 15 MPH.   I feel some vibration in the foot pegs which I have never felt before the tire swap.  At first I thought that it was just the knobs on this new tire but now I believe it to be related to the motor in some way. 

Could changing the rear tire size affect the motor feedback loop someway?   Where does the Zero get it's speed data from for the speedometer and is that fed back into the servo loop somewhere?

After changing to a larger diameter rear tire I now have some roughness in my Zero motor's operation.   It is worse at right around 15 MPH.

[Richard230]

I really like how the new tire grips in the loose stuff but there is a problem:   I now have some vibration and motor unsmoothness at certain speeds.   It is most noticeable at around 15 MPH.   I feel some vibration in the foot pegs which I have never felt before the tire swap.  At first I thought that it was just the knobs on this new tire but now I believe it to be related to the motor in some way. 

Could changing the rear tire size affect the motor feedback loop someway?   Where does the Zero get it's speed data from for the speedometer and is that fed back into the servo loop somewhere?

After changing to a larger diameter rear tire I now have some roughness in my Zero motor's operation.   It is worse at right around 15 MPH.

This morning I just read some complaints about some street-legal off-road tires having vibrations at certain road speeds on a BMW GS forum that I frequent.  So it might be the tire.  Perhaps the thing to try is to let the bike roll down a hill with the ignition off and see if you notice the vibration.  That should tell you if it is from the tire or the drive train.

[BSDThw]

Could changing the rear tire size affect the motor feedback loop someway?

Technical I don't think so!

Where does the Zero get it's speed data from for the speedometer and is that fed back into the servo loop somewhere?

The Sevcon tells the RPM it has also some calculation from Rotation to speed, but I don't know how Zero use it. I know that you can change the speedometer ratio, maybe Zero do some other calculation

The Sensor for rotation (Sin/Cos encoder) is located at the motor, it is the plug at the left side Encoder + Temp sensor.

So your tire shouldn't have an effect to the encoder.

Do you really think it isn't the tire? Maybe you suffer of "German Angst" 
 

 

[WindRider]

Hey Richard and BSD,

Thanks for the responses.

I will try the downhill roll test later today... I know just the spot for this test.

"Greman angst?"   LOL.   The first day I had myself convinced that it was just the tire but on the ride in today I was sure it was the motor.

More later.

[nicktulloh]

When I first got mine the dealer had the pressures set at 27/27. The vibration starting at about 45 mph made the bike almost unrideable. I pumped them up to 32/35 and most of it went away. I'm hoping that the conversion to Avons gets rid of the last of it.

[WindRider]

As Richard suggested I shut off the key and coasted down hill, no power.   Sure enough, the vibration happened right around 15 MPH so it must be the tire.   Thanks for the suggestion Richard.   I will experiment more with tire pressure, right now at 32 PSI front and rear.

Must just be that "German Angst" as diagnosed by BSDThw.   :  )

[firepower]

Also Make sure the tire are balanced, exrea weights added to the rim, offroad tires can be very unbalanced.

[Richard230]

My guess is that the problem won't be solved by balancing the tire.  A tire out of balance will tend to hop up and down and will get worse the faster you go.  A vibration, especially one that only occurs at certain speeds, is most likely a characteristic of the tire's tread design that you may just have to live with.  Obviously you should make sure that the wheel is balanced, but I can't think of anything else you could do, other than adjusting air pressure, that might reduce the vibration that you feel.  And it is better to have air pressure set to provide you with the best on- or off- road performance, than one that just reduces the vibration.  But it never hurts to experiment and the important thing is that your fears of mechanical problems are resolved.   

[BSDThw]

I do not know if to laugh or cry!

I have an appointment next Friday at the TÃœV because I will run a 120/80 -R16 on my 2012 DS and I need to change it in the paper, if not I run in trouble with police or the all 2 years TÃœV examination

Today I have had my date, but it turned out in the wrong way!

We all know a 120/80-R16 fits well, so the TÃœV inspector could see there is plenty space. Then he was asking his computer and it went out a 120/80-R16 standard rim is 2.75x16 and my 3.00x16 is to WIDE for this tire actually a 110/90 shouldn't be on that rim at all
Of course the inspector knows that a 120/80 will run pretty good at this rim but now I need a "tire approval" from Michelin using a 3.00x16 rim for a 120/80 City Grip

Why is life so complicate in Germany
 

[Richard230]

The Germans do love their rules and regulations.     It all started with the Prussians, I believe.   

I think it all started when the Prussians started putting spikes on their military helmets.   

[firepower]

always wondered about that spike, obviously would stop Germans sitting on there helmets, would have been a nightmare for stores and shipping , lol

[dahlheim]

The Germans do love their rules and regulations.

they really do go overboard over there, though.  and i thought new jersey was a police state.  they have nothing on germany. viel glueck mit Michelin.

[BSDThw]

It all started with the Prussians, I believe.

Hi Richard nice try to tease me but I am from Bavaria and Prussians and Bavaria tease each other also, therefore I 100% agree with you

viel glueck mit Michelin.

Yes I am not sure how cooperatively Michelin is, They have a Contact Form for this, I did sent; see what will happen.

I have to add, the Inspector is nice and helpful I do run the tire now and if police stop me I shell tell them to contact him, so I should not run in trouble Instead of using my old one with a tread under 1,6mm!