Wobbling sensation on v5f+......feature or issue?

[Paddylaz]

Hey guys, I experienced for the second time, a phenomenon.

When I was at 3 bars of battery yesterday (just about to drop down to 2, I think) I got a sort of 'wobble' sensation. It's from left-to-right.

I've had this sensation only once before, a long time ago. Can't remember if that too occurred at low battery.

Is this a feature or an issue? I only suggest the possibility of it being some sort of safety feature because it comes on in a very consistent, controlled way. Has anyone else had this? You can still ride it, but you find yourself lowering your speed as it feels quite unnerving.

Cheers!

Paddy.

[Mono]

...or maybe a coincidence. 

[steve454]

2 hours ago, Paddylaz said:

Hey guys, I experienced for the second time, a phenomenon.

When I was at 3 bars of battery yesterday (just about to drop down to 2, I think) I got a sort of 'wobble' sensation. It's from left-to-right.

I've had this sensation only once before, a long time ago. Can't remember if that too occurred at low battery.

Is this a feature or an issue? I only suggest the possibility of it being some sort of safety feature because it comes on in a very consistent, controlled way. Has anyone else had this? You can still ride it, but you find yourself lowering your speed as it feels quite unnerving.

Cheers!

Paddy.

Sounds like a solowheel feature, but they only shake to indicate.

[Ombre]

My V5F doesn't wobble left to right.  It does gently tilt back with a faint oscillation when voltage gets low, at high speeds.  I don't see how the wheel could cause a left to right wobble, so I would suggest maybe it's your legs getting tired.

[Chris Westland]

3 hours ago, Paddylaz said:

When I was at 3 bars of battery yesterday (just about to drop down to 2, I think) I got a sort of 'wobble' sensation. It's from left-to-right.
I've had this sensation only once before, a long time ago. Can't remember if that too occurred at low battery.
 

I get this "wobbling" on my V8.  It usually happens after I've been riding an hour or so (so maybe my battery is down to 40-50%) but I attribute it to: 

1. getting 'velocitized' ... I get used to going faster and faster, so any small undulation provides more side forces on the wheel

2. getting more relaxed in the ride, so I tend to grab less with my legs, and just use weight adjustments to control the wheel.  This allows me to lean and control with more freedom, but gives the wheel opportunity to react to the terrain without being controlled by my legs.

3. my legs getting tired / relaxed / wobbly

Don't know if this explanation works for you, but I'd call it a "feature" not a "bug"

[Maximus]

I keep hoping that the wobbling will go away in time. I love going fast, but as soon as I do, either the wobbling begins or my fear of it does ...  I have no experience on any other wheel but I assume the the wheels with a larger width (kingsong?) wobble less because there is less play side-to-side between your calves and/or knees. I love the maneuverability of the inmotion wheels but I believe the flip side is a little less control at faster speeds...?

[Mono]

I wonder if someone has experience in how changing to a different tire influences the wobbling issue?

[Paddylaz]

 

On 15/04/2017 at 1:23 AM, Ombre said:

maybe it's your legs getting tired.

Lol.

Unless my legs have become possessed by the devil I'm pretty sure it's the wheel. It's a pretty pronounced sensation.
 

 

*looks anxiously at legs*.....................THE POWER OF CHRIST COMPELS YOU

[phatmike]

what about tire pressure? My V5F+ wobbles under 2.7

 

[Rehab1]

14 hours ago, Paddylaz said:

When I was at 3 bars of battery yesterday (just about to drop down to 2, I think) I got a sort of 'wobble' sensation. It's from left-to-right.

Hopefully you can reproduce and quantify the wobble. I have not had this issue with my V5F+  or V8 both of which have been drained down to 1 bar. 

Test Idea (this may be difficult depending on your location to access your charger)

If you encounter the wobble again at 3/2 bars stop riding and charge it for 15 minutes. Ride again on the same surface and incline (preferably 0 degrees) . The idea is to reproduce the sensation. 

Now if the wobble is significant enough it should transmit a vibratory visual. Try to take a video focusing on your feet or fender as the wobble is taking place. Hopefully we can see the wobble in action at some point. 

[Paddylaz]

14 minutes ago, Rehab1 said:

Hopefully you can reproduce and quantify the wobble. I have not had this issue with my V5F+  or V8 both of which have been drained down to 1 bar. 

Test Idea (this may be difficult depending on your location to access your charger)

If you encounter the wobble again at 3/2 bars stop riding and charge it for 15 minutes. Ride again on the same surface and incline (preferably 0 degrees) . The idea is to reproduce the sensation. 

Now if the wobble is significant enough it should transmit a vibratory visual. Try to take a video focusing on your feet or fender as the wobble is taking place. Hopefully we can see the wobble in action at some point. 

Yeah that's a good idea.....I might try that.

Only problem of course is the rarity that this occurs. It's only happened twice in the entire time I've owned the wheel (and I was one of the first). That's why I've ruled out most of the possibilities others have suggested (tired legs, tire pressure etc). If I had to guess I'd say it may well be some sort of safety feature related to voltage/current etc. But then it doesn't seem anyone else has really experienced it.

Anyway, thanks guys! Don't where we'd be without the forum for discussing these sorts of gremlins.

[Mono]

On 2017-4-15 at 2:00 PM, Rehab1 said:

Now if the wobble is significant enough it should transmit a vibratory visual. Try to take a video focusing on your feet or fender as the wobble is taking place. Hopefully we can see the wobble in action at some point. 

With the V8 I can reproduce wobbling at pretty much any speed and any charge level. My current favourite hypothesis for the cause is the deep S-shaped tire tread line close to the middle of the tire.

EDIT: and here my favourite hypothesis goes out the window:

 

[Chris Westland]

 

54 minutes ago, Mono said:

With the V8 I can reproduce wobbling at pretty much any speed and any charge level. My current favourite hypothesis for the cause is the deep S-shaped tire tread line close to the middle of the tire.

I would buy the "tread" explanation.  I get the most wobble when I am leaning into a turn, and this is where the tread would have the most effect.  I also notice it is more pronounced at higher pressures.  I keep my V8 at about 3-3.5 bar (factory is 2.8 bar).  If I drop below 2 bar, the wheel is more stable, albeit a bit mushy.  I like 3-3.5 bar because the wheel is much more controllable at low speed (smaller contact patch), and behaves like a 14".  When the pressure is low, it tends to grab at low speeds, and is harder to turn.  

[abinder3]

Other possibility is the feet aren't fully planted on the foot rests (pedals). 

 

Allen

[MaxLinux]

46 minutes ago, abinder3 said:

Other possibility is the feet aren't fully planted on the foot rests (pedals).

I find my wheel tends to wobble when my feet are spread wide. I get the best stability with my feet snugly against the wheel body. This makes me think the thin body of InMotion wheels could be a factor in wobbling, as mentioned by Maximus.

[Chris Westland]

I experimented with my V8 today to see if the center of gravity (CoG) makes a difference (somewhere, I'd read that the wobbling occurs when your weight is forward or back of the contact patch on the EUC).  In fact this is the case for me.  If I move my feet too far back or forward on the pedals, with my CoG in back/forward of the contact patch, I get wobbles.  The reason is clear to me.  If e.g., the CoG is to the rear, any slight imbalance in the left and right foot will cause one side to dip; this will create a torque vector at 90 degrees that pushes the wheel to dip on the other side, and so forth in reverse ... the result is a series of wiggles that your feet are attempting to control.   To get rid of it, make sure your hips are straight over the contact patch (your milage may vary, but it works for me).

[Mono]

You can't change the CoG relative to the wheel and keep the same speed and direction. You can change the foot positioning and that doesn't (necessarily) change the CoG.

[Chris Westland]

8 hours ago, Mono said:

You can't change the CoG relative to the wheel and keep the same speed and direction. You can change the foot positioning and that doesn't (necessarily) change the CoG.

Uhh ... explain?  If I step back on the pedals, my body's CoG (and thus CoG of the wheel-body system) moves backward; if I do this without changing the angle of the pedals, speed and direction are unchanged.  Paint me a picture of how you see this ...

[Mono]

14 hours ago, Chris Westland said:

Uhh ... explain?  If I step back on the pedals, my body's CoG (and thus CoG of the wheel-body system) moves backward; if I do this without changing the angle of the pedals, speed and direction are unchanged.

If speed and direction does not change, you have not changed the CoG. You have changed the part of the foot which supports the CoG directly. You have not changed the position where the mean weight hits the pedal from above. It is always good to remember that the driver essentially acts like an inverted pendulum https://en.wikipedia.org/wiki/Inverted_pendulum. The behaviour of the pendulum can be fully predicted by knowing the contact point, the GoG, and the acceleration (of the cart). OK, I left out air resistance which becomes an additional complication with speed.

Moving the foot to the back means putting more weight on the forefoot. Moving the foot to the front  means putting more weight on the heel, which is usually more comfortable. Sorry, I don't have the time to make a picture, but there is really nothing secretive or too complicated about it.

[vladmarks]

On 14/04/2017 at 9:55 PM, Paddylaz said:

When I was at 3 bars of battery yesterday (just about to drop down to 2, I think) I got a sort of 'wobble' sensation. It's from left-to-right.

Not sure if that's what you were explaining? Haven't come across anything like that riding the V5 range, so I wouldn't imagine it being a feature.

 

[Roll_On]

Still new to V8, and done about 30 miles of commute to work. I have installed the Maxxi Hookworm (16x1.95) tire to eliminate the rubbing issue (tire on plastic shell).

I do get wobbles sometimes, and it is due to the imperfection of the pavement. At a constant speed on flat street about 10 mph (not fast due to lots signals) wobble starts when the tire hits some imperfection of the street, and with no change of my feet on pedal or center of gravity (COG) change.

A good way to eliminate wobble is to change the EUC speed either by increasing or decreasing to eliminate this cyclic wobble (rotating equipment hitting a harmonic note).  I have tried with using the knee to hold tight on the EUC. This only help with small wobble.  With larger wobble it is best to change the speed (break the harmonic).

The key is to aim for a smooth ride over imperfection of the road.  Wobble prevention: like when I see a small horizontal (left to right) cracks coming up, I find it going fast over it eliminate potential wobble, or the small direction change in the tire. By lifting your weight off the EUC (slight upward movement) also help to have a smooth ride over these imperfection on the road.  Kind of like downhill skier riding over bumps.

 

[GoinPostal]

On 4/14/2017 at 10:10 PM, Maximus said:

I keep hoping that the wobbling will go away in time. I love going fast, but as soon as I do, either the wobbling begins or my fear of it does ...  I have no experience on any other wheel but I assume the the wheels with a larger width (kingsong?) wobble less because there is less play side-to-side between your calves and/or knees. I love the maneuverability of the inmotion wheels but I believe the flip side is a little less control at faster speeds...?

From the reading I have done, this wobble happens with all wheels. No one knows for sure, but the general consensus is that the cause is leg fatigue. It generally goes away and never returns as your legs strengthen. 

[GoinPostal]

On 4/15/2017 at 3:35 AM, Paddylaz said:

 

Lol.

Unless my legs have become possessed by the devil I'm pretty sure it's the wheel. It's a pretty pronounced sensation.
 

 

*looks anxiously at legs*.....................THE POWER OF CHIRST COMPELS YOU

It is an oscillation of the wheel, but the culprit seems to be fatigue in the legs. 

I ride the Segway S1. It actually threw me off the wobble was so severe. At that time I researched the heck out of this subject. I didn't want to believe it was fatigue in my legs either, but as the old experts in the hobby told me, it went away on its own and has never returned. The only explanation given those facts, is that your legs strengthen and it goes away. 

[esaj]

15 minutes ago, GoinPostal said:

It is an oscillation of the wheel, but the culprit seems to be fatigue in the legs. 

I ride the Segway S1. It actually threw me off the wobble was so severe. At that time I researched the heck out of this subject. I didn't want to believe it was fatigue in my legs either, but as the old experts in the hobby told me, it went away on its own and has never returned. The only explanation given those facts, is that your legs strengthen and it goes away. 

While this probably usually is true, Paddylaz has been riding for what, two years? And probably is way past 1000km on his V8 V5f+...

[Keith]

10 minutes ago, GoinPostal said:

The only explanation given those facts, is that your legs strengthen and it goes away. 

Whilst leg strength is clearly part of the problem I do not believe it is the only explanation. I think a part of the problem is also leg positioning. Many beginners tend to position their feet so there is equal overhang back and front of the peddles, that is actually slightly too far back and means the user has to lean forward too much so as to compensate for their position. That also can set up wobbling. As users become more proficient, then their foot positioning and stance also improve as well as their leg strength and all those things (IMHO) have an impact on wobbling reducing.