Where is the problem located at?

[Nvreloader]

I just took a short ride on my new Juggs 4 bike, on a smooth paved bike trail.
I had the bike loaded with my 2 packs (Gear/tools/water, normal setup etc.)
the one pack weighs 25#'s and the other at 20#'s, the 3L water bladder
I am carrying on my back.

I have never encountered this problem on the WH bike with over 1900 miles xc trail riding.

I had a severe front end shake/wobble, bad enough I could not take my hand off one side of the bars, I had to ride with BOTH hands to control the shimmy.

The 20# pack was in the front basket and the 25# pack was in the rear basket.
I checked the bike several times and could NOT find any problems with the front end/tires etc.

I have my Wart Hog set up the same way and never a problem.

The only thing I notice between these 2 bikes, is the Juggs 4 has ALWAYS/seems to be very LITE/quick handling of the handle bars, compared to the WH.
Tire's pumped to - 5 #'s below the OEM rating spec's.

Could the HB stem need tightening up?

Your thoughts or suggestions on changing the load ratio Front/Back,
back to testing.....Tia

 

[Slaphappygamer]

Seems like it may be the Juggernaut. As a test, you could make the same, or similar, ride without the extra packs. Or remove only one and test again.

 

[Tars Tarkas]

Why do you carry 30 liters of water?

TT

 

[keithj69]

"I had a severe front end shake/wobble, bad enough I could not take my hand off one side of the bars, I had to ride with BOTH hands to control the shimmy."

Double check the headset. Sounds like the fork is not properly tightened down. Had this issue when I had a battery strapped to the rear rack and I stood up to take the load off the rear shock. Handlebars went into a death wobble.

Edit: the reason I caused this issue... I changed out the cap on the fork for one that has a Garmin mount. When I switched out, I did not loosen the stem bolts, make the proper adjustments and there was enough differences between the 2 caps that It caused this issue. It took me months to figure this out as I never really rode in the setup I had that day. Once I figured it out, It was night and day, and I could ride again without hands. Being a new bike, maybe QC missed it.

 

[Nvreloader]

Why do you carry 30 liters of water?

TT

TT
I made a Fat Fingered mistake, should have been 3.0l of H20...lol
(Corrected the problem.)

 

[Kayakguy]

Why do you carry 30 liters of water?

TT

The post said 3 liters of water, not 30.

 

[Nvreloader]

Seems like it may be the Juggernaut. As a test, you could make the same, or similar, ride without the extra packs. Or remove only one and test again.

SHG
When I first got the Juggs 4 bike, I took a quick test ride on a back dirt road, I felt a very slight HB shimmy and thought it was the dirt rode.
I'll test with the same packs/loading as the paved bike trail, I know where is this section is....
Tia,

 

[Nvreloader]

Keith
Thanks for the video, I'll pay close attention when viewing it.
Tia,

 

[Tars Tarkas]

TT
I made a Fat Fingered mistake, should have been 3.0l of H20...lol
(Corrected the problem.)

Ha! That's a lot more reasonable!

TT

 

[gromike]

The post said 3 liters of water, not 30.

He edited the post.
I saw the 30 liters in the original post, but didn't think about it too much. I thought he must like his water. But in retrospect, that 30 liters is 8 gallons, and that's 60+ pounds on the back. So, definitely an order of magnitude mistake, though I had no idea when I first read the post. I just thought he must live in the desert world.

 

[Tars Tarkas]

I just thought he must live in the desert world.

Or he's an e-bike firefighter.

TT

 

[Nvreloader]

You are both right, I live in the High Desert and I have been a fire fighter, you can NEVER have too much water here, don't have to worry about anything now, as I am RETIRED and I can do anything I want as long as it's legal.........Lol I think.
Tia, ymmv

 

[Nvreloader]

I took the loaded bike on the dirt road where I got the slight shimmy before, the bike did the same thing only worst, this time.
When I got home I checked the headset, I found that the headset setting was very loose, I tighten down the headset about a turn and a half on the locking bolt to the star washer (was very loose) and it seemed to feel quite a bit tighter in movement.
I take the same ride when it cools down this afternoon.
ymmv

 

[Nvreloader]

Guys
I don't know what to think, I have tried EVERY combination of loading the above packs on this bike, I have tightened the headset up to almost max tightness etc.

I still have the front end shimmy, bad enough I can't take my hands of the H Bar, loaded or Unloaded. There is something wrong, I just can't find it yet.

The only thing I have not changed, is the seat adjustment for/aft,
this seat has 4" adjustment on the seat rods, I am at DC (dead center), 2".

The question I have now is,
Could CG (center of gravity) be coming into play?
As this bike seems to be acting like this might be the problem,
after all the testing I have done..

Thoughts and suggestions...
Tia

 

[dodgeman]

I googled bicycle front end shimmy and what I found is a front suspension can cause it and large heavy tires can also. I’m not familiar with your bike, does it have a larger heavier tire and front suspension?

 

[PCeBiker]

I googled bicycle front end shimmy and what I found is a front suspension can cause it and large heavy tires can also.

The question I have now is,
Could CG (center of gravity) be coming into play?
As this bike seems to be acting like this might be the problem,
after all the testing I have

You might want to try balancing your wheel.
I've been trying to get rid of a front end shimmy for a couple months now.

I just finished balancing my new wheel.

I used a fishing weight as a weight.
I needed a pretty heavy weight to balance the wheel.

You set your forks sideways and make sure the fork tubes are level, then put a weight opposite the heavy spot.

I had to file the slot open more on the weight so it would fit over the spoke, then I pinched it on to the spoke.

I'm having a hard time trying to balance the rear wheel because of the motor and clutch drag.
The wheel won't settle at the heavy spot so it's been tons of trial and error.

 

[Nvreloader]

PC
Good Idea,
but it won't work for me, I have 8-10oz of Flat Out in each tire tube.
If I didn't have the Flat Out in the tubes, that should work OK. ymmv

 

[PCeBiker]

Yeah,.. it says right on the package that the tires need to be balanced before adding the FlatOut.

I'm going to try and get my wobble figured out before I add the FlatOut.
I carry ⅓ of a bag with me now that I'll use if I get a flat.
I carry the valve core tool too.

 

[Nvreloader]

D man
The tires on this Juggs 4 bike are 26x4.0" Choa Yangs,
with 8-10oz of Flat Out in each tube.
Yes, it has RST guide front suspension.
I don't know if you could call these tires heavy?

I am tempted to make a CG bar/4-5' long, that picks up the bike, then move the bike until I get a balance point, when fully loaded, then I would know.
I have a feeling that the CG point is ahead of the seat post, due to the battery's position along with my 200# weight sitting on the seat.
Thanks,

 

[gromike]

Have you taken the forks out of the frame and inspected the bearings and races of the headset. It would also be good to do teardown and rebuild the shocks. It could just be your front tire.

Bad geometry or weight balance can be a serious thing. I have had 3+ decades living with a broken collar bone due to bad frame geometry. I put drift bars on a cross bike and had them extended to the max so I could fit the shifters and brake levers. That was one comfortable ride, but at speed it would steer with a slight sinusoidal wave. The faster you went the worse it got, and when I got to a 30+ mph downhill run I found myself riding a road bike in a gravel ditch.