Where is the problem located at?

[PCeBiker]

@Nvreloader

Lean your e-bike over on the kickstand to get your rear wheel in the air and slowly wind up the wheel with your throttle.

That's how I could tell my wheel was out of balance. The bike started to shake on the kickstand.

My first e-bike did that from new, but I couldn't feel anything while riding.

That's why I added the FlatOut (and Tannus inserts, and Mr. Tuffy tire liners) to my wheels because I figured "good enough".


It wasn't until I added the second battery a year later that the wobble started and would go out if control if I rode no-hands.

So now on my new e-bike, I'm not adding the FlatOut until I get my wheels balanced and wheels/tires true.
I carry the flat-out with me to add if I get a flat instead.

 

[Nvreloader]

PC & Guys
Look at Photo's 1/3/5 and tell me what you see, pay attention to the basket in relationship to the rear wheel center line TDC and then the CG of any load + the water bladder is at TDC or over when I am wearing it.

I just finished moving the basket 3" towards the front wheel,
I haven't moved the seat forward either.

I had a slight HB shimmy on the ride, with NO equipment added, baskets etc, had the OEM rack on the back.
Thoughts and suggestions..........
Tia

 

[PCeBiker]

I just finished moving the basket 3" towards the front wheel,
I haven't moved the seat forward either.
Thoughts and suggestions..........
Tia

Yes, I think that should help.

The best place to add any weight to a bike is between the wheels and as low as possible.

Getting your seat as far forward as possible should help as long as it doesn't affect your ability to pedal comfortably.

I had a problem with my seat hitting the battery when my seat post compressed so I had to mount the battery hanging off the end of the rack.

My new e-bike has enough rack clearance to mount a battery bag to my rack.

I put my dense and heavy tools in my frame bag to move weight as far forward as possible.


Keep in mind that if I had a perfectly balanced bike, I could weigh down the rack until the front wheel is barely touching the ground and I wouldn't get a shimmy or wobble.

Adding weight doesn't cause a shimmy, it just amplifies what's already there, until you can't let go of the handlebars.

 

[Nvreloader]

I don’t see in the discussion yet if this happens when the bike does not have 45 pounds of cargo.

As others have mentioned I’d be concerned about the headset, h various bearings, trueness of wheels, etc. post a picture of the bike?

I posted about the handle bar shimmy in posts 7&13,
loaded was the worst etc.

I am going over everything with a fine toothed comb, again,
I got my neck bowed now.....Lol
Thanks

 

[Nvreloader]

If the blasted winds will lay down for a couple hours,
I'll test the 25# bags option, by moving one at a time from the back to the front, to either confirm or delete that possible theory.
Tia

 

[keithj69]

Keith 69
My phone is a:
Samsung Galaxy S10e and I use Imgbb as the photo uploader
Before I allowed a upgrade? I could post a photo, took me over an hour, but I'd finally get a photo posted here.
I tried for over 2 hrs a couple days ago and got nothing. So I quit as I was getting cross eyed.
There has to be a better way, as this electronic stuff and I DON'T play well together. Thanks

Open up Gmail, start an email, attach the photos. Give it a moment to save, then open up Gmail on a computer and go to drafts. The photos should be there. Or on that email you can just send it to yourself.

 

[Nvreloader]

Thanks Keith
I'll try that method.......I have to find some thing that I can do reliably,
as me and the plastic electronic box don't play good together...
as I found out..... lol

 

[keithj69]

After looking at your setup, it reminded me of a time that I tried to carry 2 spare batteries that caused a perfectly fine ebike (himiway cruiser non step through) into a death wobble. It was then that I decided to start using panniers. There are probably physics and science involved. Once I switched to bringing the weight lower and closer to the bike I had no issues. Your bike may be ok. But being a step through can also be the issue. You may want to rethink how you carry things. The bike may be fine and you are just magnifying the whole step through frame flex thing. Also I just used my example of a draft email to get this picture off my phone to chromebook.

What I found was the rack platform I bolted onto the rack (like your basket) acted like an anti- anti- rollbar and just sent all the slightest vibrations/movements up through the frame in such a magnified way that the bike was unrideable. As soon as I took off that platform from the rack, added 2 panniers and carried the exact same stuff, I had no issues. Just carrying 1 pannier with a battery made the bike semi weight loopsided, which meant I needed to be aware of drifting to a side if going hands free. Getting on the bike meant I would lean the side down without the pannier if I rode with one spare battery pannier.

 

[Nvreloader]

Thank you, Keith
What would you estimate your total load was on the back?

When I first got this bike, within 1 day, I took it and rode a dirt road behind the house at my usual speed of 10-12mph and felt a slight handle bar shimmy and I felt/thought it was the road I was riding, now I am wondering IF was it the road?.

This bike was straight out of the shipping box and only had the OEM rear rack installed.

I have sent this info to Biktwix, about the HB shimming and waiting for a reply, from Roshan.

I really like this bike and hope I can find/cure this problem,
+ the better half like this bike also.
Tia,

 

[PCeBiker]

I have sent this info to Bikonit, about the HB shimming and waiting for a reply, from Roshan.

You mean Biktix right?
Do both your ebikes have a shimmy?

 

[Nvreloader]

PC
No, my Wart Hog has never had a problem of any kind,
except for the OEM battery recall, which went very smooth.
Tia,

 

[PCeBiker]

PC
No, my Wart Hog has never had a problem of any kind,
except for the OEM battery recall, which went very smooth.
Tia,

Can you swap the front wheels between the two e-bikes to see if the shimmy follows the wheel?

It could provide some proof for Roshan.

 

[keithj69]

Thank you, Keith
What would you estimate your total load was on the back?

When I first got this bike, within 1 day, I took it and rode a dirt road behind the house at my usual speed of 10-12mph and felt a slight handle bar shimmy and I felt/thought it was the road I was riding, now I am wondering IF was it the road?.

This bike was straight out of the shipping box and only had the OEM rear rack installed.

I have sent this info to Biktwix, about the HB shimming and waiting for a reply, from Roshan.

I really like this bike and hope I can find/cure this problem,
+ the better half like this bike also.
Tia,

I think I had around 22-25 lbs on the back in that setup. If you get someone to pickup the front end of the bike, Can you grab the front tire and shake it side to side to see if there is any play? On one of my ebikes, I think it was the Frey, they mentioned to make sure that when taking off the plastic protective ring they had on the tire to make sure to grab the spacer so that the front tire fit. I am thinking you may not have that issue with the 4" tires you have, but worth a look. Just because it is new doesn't mean something wasn't done correctly from the factory. I hope you can get pictures/videos to Biktrix.

 

[Nvreloader]

PC
I don't think, I can change to the WH front wheel,
2 different front wheel locking systems and 2 different sizes etc.
Tia

 

[Nvreloader]

Keith
I converted this lifting device to work on my E bikes,

Hoyer Lift - Health and Homecare

Elevating hydraulic lift. Base opens with an easy hand lever. 6-point cradle type.

healthandhomecareinc.com

(it lifts 500+ #'s), plus it will come in handy,
when I crash and burn, so the better half can lift me
in and out of bed......LOL

It was given to me, works very well and easy to use,
I can lift either end or the whole bike off the ground,
to work on whatever problem I have at the time.

I'll have to build a slightly longer straight arm,
(needs about 16/18" longer), so I can pick the whole bike
up and spin it around to work on either side, without moving etc.

I'll lift the front end and see if there is anything loose etc.
Thanks,

 

[Nvreloader]

Keith
As a follow up,
I lifted the front end off the floor, and shook, moved, turned the HB in every direction possible, pushed the front wheel forward and back + side to side using both the tire and handlebars, feels solid and smooth, and found NO excess movements/play etc.

I am still leaning towards the CG balance angle, only because the bike had a slight HB shimmy when Brand new and was in OEM configuration, and nothing was added to the bike.

In figuring the CG of this bike, using this diagram/spec's:

Juggernaut Ultra Duo 4 Step-Thru

Unlock the full potential of your biking adventures with the Bafang Ultra M620, the most powerful torque sensor electric bike on the market today. Designed for riders who demand the highest levels of performance, power, and versatility, the Bafang Ultra M620 is the ultimate choice for conquering...

www.biktrix.com

As a SWAG, would you use the # 14 or #15 length when figuring a CG point. I am thinking #15 length, or the edge to edge measurement of the basket lengths of 58"/59"?.

Note, I'll make a a long 2" pipe with a set of hooks that grab the front and rear baskets ends.

I have a small front and small rear baskets that are 12x12" F and
12"x 18" R, that are attached to each ends.
Right now the Front basket extends approx to the center line 90* of the front axle, and the rear basket extends approx 11" past the rear axle 90* centerline.
The total distance from front edge of basket to the rear edge of the rear basket is approx 58/59" length.

I can then slightly lift the bike off the ground via moving the lifting spot back or forth along the pipe length, to find the CG spot.

As a SWAG,
I am thinking that the CG spot will be between the seat and rear wheel 90* center line, given the location of the dual battery's,
BUT not including anything loaded in the baskets etc, which will change the CG if wrongly loaded.

Roshan has the photo's and info, awaiting his reply.

Thoughts or suggestions...
Tia.

 

[keithj69]

This video just came out in reference to ebikes with wobbles. Hopefully it will help give you some ideas.

 

[Nvreloader]

As a follow up to this handle bar shimmy/shaking problem,
here is some info on what I found via this test.

I had 125#'s of bagged lead shotgun pellets, 25#'s per bag. I loaded all the 125#'s in the back basket and I could NOT ride the bike, the handle bars were violently shimming/shaking so bad, I could just barely hold on, rode less than 20'.
Moved 1 bag to the front basket, still had violent HB shaking, Ride distance about 75'.
Moved a second bag of shot to the front basket, still had shaking, but did have a decrease in HB shaking,
Moved a 3rd bag to the front basket, decreased the shaking about 1/2 of what is was, able to ride smooth pavement/dirt/gravel roads, but still had to hold onto the HB, with a firm grip.
Moved the 4th bag to the front, reduced the HB shaking about 25+% more, I could lightly hold on the HB and ride everything ok.

Rode home, removed all the bags except 1, left it in the front basket, there was also the security cables/locks in the front basket also, about 5#'s (weighed). 30#'s total weight in the front basket.
Nothing else on the bike except me at 200#'s.

Upon riding/testing a the same road conditions as before, I had no HB shaking/shimmy that I could feel or see, I could ride hands free, not very good at it yet.

This bike is very sensitive to how much is loaded on the front/rear baskets.
I know now to load the front heaver than the rear.
I have had no problems with the WH bike.
ymmv

 

[PCeBiker]

This bike is very sensitive to how much is loaded on the front/rear baskets.
I know now to load the front heaver than the rear.
I have had no problems with the WH bike.
ymmv

It sounds like you might be able to deal with the problem by how you load your bike, but if your Juggernaut can't carry all your gear like your Warthog could, then that's a big problem.

I would seriously consider returning the ebike if it can't do what it is supposed to do.

The Warthog is rated for a 300# load and the Juggernaut is rated for 330#, so it should be able to carry more weight.

Any wobble carrying the maximum load shouldn't wobble with your hands on the handlebars.

 

[Tars Tarkas]

I had 125#'sb of bagged lead shotgun pellets,

No judgment, but why?

TT