ERider 8000W scooter - Australia (similar to xm5000li)

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pcarlson1979
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Johnny J wrote:

One thing I noticed is that at top speed there are quite severe vibrations

Yes that's right Johnny, but the vibrations are not from the wheels, it is from the motor. The forward current has reached back EMF level which means the bike is trying to activate regen. It does the same when full throttle with the bike on the center stand.

To be honest, they really should have stopped regen after 90% throttle. Just out of interest, how much do you weigh? I'm about 120kg, maybe that's why I max out at 82km/h on the flat.

__________________

------------------------------
eRider 8000w Scooter - PDT Version
72v 50AH CHL battery
350A Sevcon controller

24km: Delivered - 24 September 2011
2490km: Installed dual 35w HID lights Bi-Xenon Projectors - 27 November 2011
8313km: Installed BMS - 13 October 2012

"Scrappy" - Custom 48v Electric Dirtbike Conversion
20 Feb 2012: Bought 2005 Suzuki DRZ-400SM Motorcross Bike for $100
Motor: MARS ME0708
Controller: Alltrax AXE4844 400A controller
Battery: 16xCHL 50Ah LiFePo4 = 48v

Johnny J
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

To me it seems like the vibrations mostly comes from the front wheel, the regen on my bike is set very mildly, almost not noticable.

I weigh 75kg right now, lost about 15kg a couple of years ago, it´s the sweet stuff that´s the culprit. :-)

pcarlson1979
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Johnny J wrote:

To me it seems like the vibrations mostly comes from the front wheel, the regen on my bike is set very mildly, almost not noticable

Hmm. That's a concern then. It may be a wheel balance problem.

__________________

------------------------------
eRider 8000w Scooter - PDT Version
72v 50AH CHL battery
350A Sevcon controller

24km: Delivered - 24 September 2011
2490km: Installed dual 35w HID lights Bi-Xenon Projectors - 27 November 2011
8313km: Installed BMS - 13 October 2012

"Scrappy" - Custom 48v Electric Dirtbike Conversion
20 Feb 2012: Bought 2005 Suzuki DRZ-400SM Motorcross Bike for $100
Motor: MARS ME0708
Controller: Alltrax AXE4844 400A controller
Battery: 16xCHL 50Ah LiFePo4 = 48v

pcarlson1979
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

YOUTUBE video is up.
http://www.youtube.com/watch?v=O1p8Mn2QtqU

This is a VERY basic video of me riding the scooter on a few errands around Canberra. The first part I just used a point and shoot camera tiad around my wrist, I didn't like that so then I used a "Flip Video" camera inside my helmet and it was pressed against my nose, so I'm sorry for all the breathing noise. But I think this shows just how capable the scooter is. You don't really ride that much slower than a car driving normally.

This is just normal driving, not flat out speed driving. There is one section where I was at full throttle trying to merge with fast cars.

__________________

------------------------------
eRider 8000w Scooter - PDT Version
72v 50AH CHL battery
350A Sevcon controller

24km: Delivered - 24 September 2011
2490km: Installed dual 35w HID lights Bi-Xenon Projectors - 27 November 2011
8313km: Installed BMS - 13 October 2012

"Scrappy" - Custom 48v Electric Dirtbike Conversion
20 Feb 2012: Bought 2005 Suzuki DRZ-400SM Motorcross Bike for $100
Motor: MARS ME0708
Controller: Alltrax AXE4844 400A controller
Battery: 16xCHL 50Ah LiFePo4 = 48v

JasonTaylor
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Not bad. I liked that video much more pcarlson1979. But you crazy aussies. You are very lucky you didn't get pulled over for driving on the wrong side of the road like that. Very dangerous. Now perhaps if you can adjust the camera angle a bit with some duct tape and show us the vibration at the top speed and 110 amps we can send you our donations for pumping out the vids. Seriously not to nitpick but the noise is perhaps reduced due to the location of the camera. Put it down low, might hear more. Nice you got someone to help you fix the throttle issue. Way to go vis for v.

Jason Taylor
http://twitter.com/jasontaylor7

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Johnny J
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

JasonTaylor wrote:

But you crazy aussies. You are very lucky you didn't get pulled over for driving on the wrong side of the road like that. Very dangerous.

I hope that was a joke? :-)

Mountain chen
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

I think AU is left side driving country like UK ? It is a pity that we can't read Youtube in China

MEroller
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Mountain - vibrating front wheel on the Thunder, does that ring a bell? I mailed you about this problem not too long ago. On the Thunders I have ridden so far the problem is most evident during strong braking, and a nightmare during emergency braking. Which I was forced to do on the way home today for the first time. A car suddenly changed lanes while accelerating from a standstill just ahead of the car in front of me, and we both had to slam on the brakes full blast. My Thunder began violently bobbing up and down like a kangaroo up front, and when I had nevertheless just about stopped the bike the front wheel left the ground completely and when it landed the bike had already tipped slightly to the right, so the front wheel got a lateral shock loading upon landing. I had to let the Thunder fall on it's right flank, leaving some beautiful white scratches on the edge of the normally black lower fairing. But what is far worse that now the right telescope up front must be slightly bent because the front wheel and fender no longer line up and the handle bar needs a slight right hand push when going strait :-(

I suspect the frame itself to be partially responsible for the vibrating to a certain degree, that is why I suggested looking at reinforcing the connection of steering head and the upper longitudinal tubes. But the damping of the telescopes may also be an issue, so my dealer will puting in different oil and a little more of it, and my front telescopes where set to be replaced anyway because the original ones where not 100% o.k. I don't know exactly what was wrong with them, but my dealer is a motorcycle specialist and aparently knows his trade much better than the chassis builder of the Thunder... At least they are learning bit by bit how to improve, like actually greasing bearings and other such trivia.

A scooter or motorbike must have a rock-solid chassis in order to allow safe emergency braking too!!!!!!!!!!

__________________

My (former...) ride: E-Sprit Fury (basis is the ZAP/Erider Thunder 5000) since May 03, 2011. Mods: Battery temp. gauge and battery heating (off the grid and off the battery), Kelly KEB72801X, reverse activated, luggage rack with topcase, HC Cycle Analyst, Emsiso BMS2405, 35mm² battery cables, now wrecked

Mountain chen
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Ok,I will ask my engineer to study this problem asap.

IFIMotors
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Problem is coming from two reasons:
1. To weak from shock observers, oil must be changed and quantity need to be chcked
2. Tightened the front baring
Mountain I complained many time on front shock observers with no change.
Its time to improve front shocks

MEroller
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

IFIMotors wrote:

Problem is coming from two reasons:
1. To weak from shock observers, oil must be changed and quantity need to be chcked

That will now be happening with my Thunder. I doubt though if that alone will completely get rid of the inherent torsional instability of the front frame which also contributes to the braking vibrations. We'll see...

IFIMotors wrote:

2. Tightened the front baring

We did that, tighten the steering head bearing (just taken out the slack). That alone pushed the vibration threshold from normal harder braking to emergency braking levels. But that is just when solid contact of the front wheel to the ground is most important!

IFIMotors wrote:

Its time to improve front shocks

A wholehearted AMEN (Hebrew for a firm: so be it!) to that!!!

__________________

My (former...) ride: E-Sprit Fury (basis is the ZAP/Erider Thunder 5000) since May 03, 2011. Mods: Battery temp. gauge and battery heating (off the grid and off the battery), Kelly KEB72801X, reverse activated, luggage rack with topcase, HC Cycle Analyst, Emsiso BMS2405, 35mm² battery cables, now wrecked

MEroller
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

pcarlson1979 wrote:

YOUTUBE video is up.
http://www.youtube.com/watch?v=O1p8Mn2QtqU

This is a VERY basic video of me riding the scooter on a few errands around Canberra.

Thanks Phil for cranking out these videos! Sevcon is REALLY quiet!!! But I am still undecided if I like this or not. If my motor hums a little at full throttle I know everything is fine not only by "butt-o-meter" but also aurally, and bystanders also hear something. Right now it wouldn't be as important because the winter tires themselves howl, but silence is not always as golden as in the saying :-)

__________________

My (former...) ride: E-Sprit Fury (basis is the ZAP/Erider Thunder 5000) since May 03, 2011. Mods: Battery temp. gauge and battery heating (off the grid and off the battery), Kelly KEB72801X, reverse activated, luggage rack with topcase, HC Cycle Analyst, Emsiso BMS2405, 35mm² battery cables, now wrecked

Johnny J
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Please keep us updated how it works out with the oil change in the fork, maybe thicker oil will help.

LeftieBiker
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

I'm seeing something similar, but much less severe, with my ZEV. I thought it was crash damage but now I'm not so sure. I get a 'wobble' in the front wheel during harder braking...

Klas2k
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Hi all.
I just got my Thunder 5kw. I have a very strong vibration during normal riding. I firstbthought i may be a poorly balanced wheel, but I'll check the bearing as soon as possible.

Other than that I got a verympoor milage, down to 1 bar after 10km. But the top speed was 80kph, and voltage was betweeen 69-74 at all times.
I have charged it full now (cant be sure that tjat was done upon delivery) and see how i fares tomorrow...

/k

pcarlson1979
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Wow. With all this talk about wobbles and shakes I. A little concerned.

I just passed 1500km today, still without a problem. I don't have a thunder but I have the lightning bolt mode, which is the step through design. So far neither Amanda or I have any shakes or wobbles even under heavy braking. We do both have a slight vibration at top speed as you can feel the regen coming in. But apart from that, nothing.

I just hate how most Aussies are dumb and fearful of new technology. Today I was laughed at and yelled at for being on an electric scooter. That's the cool thing really, I can't hear them from my helmet :-) plus they would blast off in their 4wd's and leave black smoke everywhere, meanwhile I'll pass them 1 km down the road as they pull into a petrol station. HAHAHAHA!!

With just 1 opportunity charge today at the inlaws I rode 92km all up today. Even though I get home and the scooter will take 4 or 5 hours to recharge, I'm lying here in my bed all nice and warm and when I wake up, the scooter will be ready to go all over again.

__________________

------------------------------
eRider 8000w Scooter - PDT Version
72v 50AH CHL battery
350A Sevcon controller

24km: Delivered - 24 September 2011
2490km: Installed dual 35w HID lights Bi-Xenon Projectors - 27 November 2011
8313km: Installed BMS - 13 October 2012

"Scrappy" - Custom 48v Electric Dirtbike Conversion
20 Feb 2012: Bought 2005 Suzuki DRZ-400SM Motorcross Bike for $100
Motor: MARS ME0708
Controller: Alltrax AXE4844 400A controller
Battery: 16xCHL 50Ah LiFePo4 = 48v

Klas2k
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

pcarlson: If you dont suffer from the vibration even when braking hard, you dont have it :)

I have done som more investigation on my new ride.
It turned out to be really hard to get to all battery cells so I just measured two of them (they were 3.34 and 3.33 v after 4h charge), but it still feels like I may have a bad cell somewhere.
After a guaranteed full charge and 14 deg C today i took a ride of about 4km and was down to half the bars on the guessometer.
During accel I had about 67 V, on no load it went back up to 74-75 V - but either I have to high expectations on acceleration, or it feels like I cannot really get all I want out of it (which would make sense if one or two cells wasnt up for the job i guess ?))

I have also, with the help of my daughter, checked the bearings - I found no play at all. However, when rotating the front wheel it looked like it was a bit on the oval side, maybe this scooter has stood in the side stand for a couple of months and deformed the tyre...I'll have too look closer at that.

/K

MEroller
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Klas, your BMS balancers appear to lean heavily to the cautious side, 3.3 ... 3.4V max voltage is a very early cut-off in the charging cycle. That would explain your lower voltage readings and bars. My balancers appear to be set at around 3.62V and thus allow the charger to eventually reach it's maxium of 87V at final shutoff. Your instrument cluster does not seem to be calbrated according to the balancers in your battery. But a voltage drop to 67 at full acceleration and 14°C does not sound like you have some damaged cells, that is normal with conventional NiFePO4 cells (i.e. not the CHL magic).
Phil, I reckon once your BMS arrives you will also begin to have some fun with the inner workings of your Lightning. At least the hardware of your bike appears to be up to the job :-)

__________________

My (former...) ride: E-Sprit Fury (basis is the ZAP/Erider Thunder 5000) since May 03, 2011. Mods: Battery temp. gauge and battery heating (off the grid and off the battery), Kelly KEB72801X, reverse activated, luggage rack with topcase, HC Cycle Analyst, Emsiso BMS2405, 35mm² battery cables, now wrecked

IFIMotors
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

what system is your bike with?

Mountain chen
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

MEroller wrote:
IFIMotors wrote:

Problem is coming from two reasons:
1. To weak from shock observers, oil must be changed and quantity need to be chcked

That will now be happening with my Thunder. I doubt though if that alone will completely get rid of the inherent torsional instability of the front frame which also contributes to the braking vibrations. We'll see...

IFIMotors wrote:

2. Tightened the front baring

We did that, tighten the steering head bearing (just taken out the slack). That alone pushed the vibration threshold from normal harder braking to emergency braking levels. But that is just when solid contact of the front wheel to the ground is most important!

IFIMotors wrote:

Its time to improve front shocks

A wholehearted AMEN (Hebrew for a firm: so be it!) to that!!!

My engineer said that it is "High Speed Shimmy" caused by too short trail

Look at here http://www.youtube.com/watch?v=xODNzyUbIHo&feature=player_embedded

Mountain chen
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

High Speed Shimmy

You are out for a spin on your new lightweight road bike. On a steep descent you reach a speed of maybe 45 even 50mph when all of a sudden your front wheel begins to flutter back and forth and the whole bike shakes uncontrollably. You manage to bring the bike to a stop but you have just been scared out of your wits; you have experienced "shimmy."

Shimmy is usually caused by not having enough trail. To explain trail for those who don't know: If you draw a line through the center of your head tube and therefore the steering column, that straight line will reach the ground at a point (Point B.) ahead of the point where the wheel contacts the ground (Point A.)I always built my bikes with at least 2 1/2 inches of trail. Trail is common to all wheeled vehicles, cars and even a shopping cart will have it.

If you make the head angle steeper it means less trail because you move point B closer to point A. Also if you increase the fork rake (Fork offset.) you make for less trail; in this case point A moves closer to point B. The worst scenario is a bike with a steep head angle and a long fork rake; trail can be reduced to almost zero. Trail keeps the bike going in a straight line, and also assists a two wheeled vehicle in its self steering abilities.

As you lean to the left, point B moves to the left and the wheel Pivoting on point A will turn to the left. The gyroscopic action of the spinning wheel also plays a big role in self steering, but this is another subject and I only mention it because the heavier the spinning wheel, the more it keeps straight. Road bikes with ultra light wheels and tires are more sensitive to small changes in the amount of trail.

What happens in a high speed downhill shimmy the wheel is turned one way or the other by a bump in the road or a gust of wind. (Like when swinging out of a pace line.) The caster action of the trail corrects this, but if there is not enough trail it will over correct and then correct again starting the wheel fluttering back and forth. You can see exactly the same thing on a shopping cart if you run with it across the parking lot the caster wheels will flutter back and forth in the same way.

Large frames are more prone to shimmy for two reasons. Large frames are taller and also should be proportionately longer, but there is a school of thought that believes a race bike should have a short wheelbase, so the builder makes the head angle steeper to shorten the wheelbase, but in doing so lessens the amount of trail. Large frames are more flexible because the tubes are longer, also they tend to have shallower seat angles to accommodate the rider's longer legs therefore the riders weight is more over the rear wheel.

Any vehicle that has its weight towards the rear is less stable; ask anyone who has driven an old VW bus in a cross wind. So if you are a tall person with a large bike frame, try to keep your weight forward when descending. Also keep your body in a low aerodynamic tuck; if you sit up wind pressure on you chest will push more weight towards the back wheel. Finally if you should get into a high speed shimmy; try not to panic, grip the top tube between your knees, and apply the rear brake first very gently and only apply the front brake after you have come out of the shimmy.

A bike with a shimmy problem usually has a design flaw in the frame and there is little you can do to correct it short of changing the frame. However do check that the head bearings are not loose. Also fitting a slightly heavier tire to the front wheel may increase the gyroscopic action of the spinning wheel enough to correct or lessen the problem. The design flaw will still be there but you have added and element to maybe alleviate the tendency to shimmy.

MEroller
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

My Thunder has a low-speed shimmy problem, somewhere in the region between 5 and maybe 20km/h. But it only occurs if I take one hand off the handle bar, and it is just about gone with the heavier IRC Urban Snow winter tires instead of the original Cheng Shin. That is the reason why I wrote that a reinforcement of the frame itself may be necessary to increase it's torsional stability. Thunder with the very high center console should have a far more sturdy connection between steering head and the rear end of the bike than a step-through scooter like the Lightning / VK2008...
One thing the Thunder surely does not have is too little trail. The head angle is considerably bigger than on most other scooters, more like a chopper motorcycle. What reduces trail a little is the fact that the bridge holding the telescopes is V-shaped instead of straight across, thus placing the telescopes slightly forward of the steering axis and reducing trail. Fork rake I guess.

HOWEVER, all of this shimmy stuff has NOTHING to do with the front suspension being clearly under-damped and bouncing up and down during heavy braking. To the point of the front wheel lifting off the ground!?§^!!! That is what needs to be addressed IMMEDIATELY!!!

The shimmy problem needs more than just an explantion, it also requires action on behalf of your frame supplier Xinrongzhou Vehicle Business.

Mountain, you wished us a safe ride. But you also need to ensure that the products which leave your premises are safe in themselves. How Thunder with this bouncing issue could ever get an EC certificate is beyond me...

__________________

My (former...) ride: E-Sprit Fury (basis is the ZAP/Erider Thunder 5000) since May 03, 2011. Mods: Battery temp. gauge and battery heating (off the grid and off the battery), Kelly KEB72801X, reverse activated, luggage rack with topcase, HC Cycle Analyst, Emsiso BMS2405, 35mm² battery cables, now wrecked

Johnny J
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Howcome noone has taken this seriously before?
I mean the "Thunder" has been on the market for a couple of years already and such dangerous behavior must have been noticed, right?

Mountain, I find it very strange if you knew about this and didn´t take immediate action, a serious accident caused by a misconstructed frame/front fork can ruin your business.

LeftieBiker
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

I once had a Suzuki GT750 "Water Buffalo" that, on one high-speed run in particular, developed a front shimmy so severe (and at 100MPH) that if I had touched the front brake I'd be dead. I got it stopped by standing on the rear (drum) brake until the shimmy stopped at about 40MPH. This was near the end of the era when Japanese bikes were known to have weak, too-flexible forks and, especially, swingarms. It looks like the Chinese bikes may have similar problems...

Klas2k
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

IFIMotors wrote:

what system is your bike with?

If that question was for me, it is not the pdt system.

/k

Klas2k
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

MEroller wrote:

Klas, your BMS balancers appear to lean heavily to the cautious side, 3.3 ... 3.4V max voltage is a very early cut-off in the charging cycle. That would explain your lower voltage readings and bars. My balancers appear to be set at around 3.62V and thus allow the charger to eventually reach it's maxium of 87V at final shutoff. Your instrument cluster does not seem to be calbrated according to the balancers in your battery. But a voltage drop to 67 at full acceleration and 14°C does not sound like you have some damaged cells, that is normal with conventional NiFePO4 cells (i.e. not the CHL magic).
Phil, I reckon once your BMS arrives you will also begin to have some fun with the inner workings of your Lightning. At least the hardware of your bike appears to be up to the job :-)

Ok, maybe I wll just have to stop looking at the bar meter and use the voltage as indicator instead...
Wonder if you can reprogram, or rewire the bms to admit a bit more charge...on the other hand i suspect that that would only give me a bit ore extra range, and i dont really need it in my daiy commute.
A more powerful controller with more rapid takeoff would be nice though...

/k

JasonTaylor
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Oscillatory resonance can occur in many forms. Consider:

http://www.youtube.com/watch?v=mDSIfFhWau8

Or perhaps the most popular thing in college physics, the SHO:

http://en.wikipedia.org/wiki/Simple_Harmonic_Motion

Cheers
Jason
Daily rants @ http://twitter.com/jasontaylor7

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Jason Taylor. Fresh rant each day @ http://twitter.com/jasontaylor7

Mountain chen
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

Actually in china bad traffic,it is very difficulty to keep even only 2 minutes 100km/h on road,my engineer never report such problem during the very few times top speed testing,so that it is difficulty for us to find it out and study .

Nowaday all electric scooter are converted from cheat gas motorcycle in china,so that there are many defects can't be improved because of basic chassis.

Thunder have been export more than 10 thousands pcs on 125cc or 150cc gas version,but no one report this problem either.

Anyway,we will take serious and maybe change into a good front shock.

Klas2k
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

MEroller wrote:

My Thunder has a low-speed shimmy problem, somewhere in the region between 5 and maybe 20km/h. But it only occurs if I take one hand off the handle bar, and it is just about gone with the heavier IRC Urban Snow winter tires instead of the original Cheng Shin. That is the reason why I wrote that a reinforcement of the frame itself may be necessary to increase it's torsional stability. Thunder with the very high center console should have a far more sturdy connection between steering head and the rear end of the bike than a step-through scooter like the Lightning / VK2008...
One thing the Thunder surely does not have is too little trail. The head angle is considerably bigger than on most other scooters, more like a chopper motorcycle. What reduces trail a little is the fact that the bridge holding the telescopes is V-shaped instead of straight across, thus placing the telescopes slightly forward of the steering axis and reducing trail. Fork rake I guess.

HOWEVER, all of this shimmy stuff has NOTHING to do with the front suspension being clearly under-damped and bouncing up and down during heavy braking. To the point of the front wheel lifting off the ground!?§^!!! That is what needs to be addressed IMMEDIATELY!!!

The shimmy problem needs more than just an explantion, it also requires action on behalf of your frame supplier Xinrongzhou Vehicle Business.

Mountain, you wished us a safe ride. But you also need to ensure that the products which leave your premises are safe in themselves. How Thunder with this bouncing issue could ever get an EC certificate is beyond me...

You wrote before that the Thunders of 2011 has different rear shocks than the 2010 - have they changed the front ones as well ?
I only did one hard brake test, but did not notice any of the behaviour you described. However, it was not an "panic brake" which is of course even harder.

Or could it be a production quality problem - the bouncing you describe could potentially come from a worn or loose bearing, or a weak front end of the frame right ?
A damper that is too soft may produce bouncing as well of course, but then it it usually a matter of leaking oil or something like that (i.e. the spring is almost undamped). You'll have to report to us once you have chnaged oil in your shocks if the situation improved.
In the case of poor dampening, it should be fairly easy to correct in the factory, a better shock absorber or a better adjusted spring vs absorber could probably do the trick ?

/K

JasonTaylor
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Re: ERider 8000W scooter - Australia (similar to xm5000li)

"Actually in china bad traffic,it is very difficulty to keep even only 2 minutes 100km/h on road,my engineer never report such problem during the very few times top speed testing,so that it is difficulty for us to find it out and study ."

Mountain Chen, I really learned a lot reading your write up about shimmies. I think it is largely bunk, but that isn't your fault. More a state of the field. But you know, there is this new thing they used in America called a test track, used to reduce injuries to consumers. Perhaps you don't need them in China since bodies are cheaper? Waste of time? Why bother if it increases cost? I am only joking. I realize you are low budget and low volume. Not a big maker. And I agree: the idea of using the motored frame is a good one and a sufficient excuse.

pcarlson1979, I am wondering if the ERider's shimmy is at 106 km/hr. Hehe. Alternative explanation for the 110a governor. Hope it is not true.

Interestingly, I also looked for HD videos of shimmies that resulted in really bad crashes, but it seems they have been removed from youtube or never were taken. Who knows why. I guess to protect young kids from becoming violent or something. Does anyone know of a good hd video showing a motorcycle or scooter wheel actually hopping off of the ground? It sort of bothers me that politics gets in the way of safety engineering in this way, but it could be much worse. It is an interesting problem.

Jason
Blog @ http://twitter.com/jasontaylor7 . A new post every day!

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