Panama jack failure!!!!!!

GoldenMotor.com

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,784
26
36
Indianapolis
I'm guessing it had a lot too do with the rack being welded on there.

Use a magnet to tell if it's aluminum or steel.
I was gonna say the same thing about that rack. I'm also kinda curious to find out if that PJ is steel or not.

On the one hand, I'm glad you saved the PJ. It is a cool bike. But I have to agree with the others too: that bike likely wasn't made to a standard that will long suffer the stresses of being motorized. Take it easy and ride safe.
 

RebelHellbilly

New Member
Apr 22, 2009
222
0
0
Salisbury,North Carolina
Yep, All coments are valid.
-Band aid on a terminal patient
-Get a real frame

I agree. Starting out the cheap way was fun, but it is obvious if I want something more durable and reliable, I will have to make that investmnet.

One of the members here says it best in his signature
"Cheap bikes are not good. Good bikes are not cheap"

The PJ is ready for pick up, and I know it just has a band aid on it.
Thanks for your interest and info.
2 of my builds have been older huffy frames never had a problem. just sold the 1 i used to ride yesterday
 

Mr.Gadget

New Member
Nov 9, 2010
96
0
0
South Carolina
The question has been asked several times about the frame being aluminum.
Yes the frame is aluminum. Not just because the tag on the bike said so.
I used a N45 1/8 x 1/4 disk magnet. (Neodymium 45 rare earth magnet,,,, very strong) It was not attracted to any portion of the frame, only parts that already known as steel.

Mabe as far as this Huffy, I just got the bad one??? Who knows, It does not bother me too much. It's not like I have tons of money invested, and, it is just a hobby.

Stay safe.
Mr.Gadget.
 
I KNOW THIS IS AN OLD THREAD but my Huffy Nel Lusso frame failed in the exact same way i have since welded the cracks an beat the crap out of it to see if it would crack again but it has not im in the process of finding a real frame an the Nel Lusso has a steel frame my guess if you get a PJ or Nel Lusso they will fail in the same spot so look out
 

donphantasmo

Member
Oct 3, 2010
372
11
18
Middleburg, FL
Off to the shop.
He called me today, and said it is ready for pickup!!!!!
All I have to do, is give it a good wipe down, and repaint the frame.
I have already found out that the flat black spray paint is a perfect match during the original build.
I'll ride it a little more gently from now on, and watch the bumps, AND give it a PRE and POST ride check. I like the MB tooooo much to give up on it.

I sure am glad I have a friend that would do it for me for next to nothing.

P.S. He actually only got a 10 pack!!!! LOL !!!!

Now the scary thing is that I have the same bike, in the same color. To make things worse, I have the same Harbor Freight trailer, and my neighbor has the same 1993 white honda accord. So, I thought you put an engine on my bike, and then tried to steel it, lol...
 

tinleyiltom

New Member
Aug 15, 2011
1
0
0
Chicago,IL
Group, I understand a few concerns with the welding, I looked at both bikes at walmart today, they look OK to me. Is the grubee gt2 the 'plug and play' kit for this bike ? The bikes were next to the cranbrooks and the frames look very similar. There is a guy selling these 'built' for $500..It could be a fun first time build too. Let me know pls....thanks guys....Tom
 

rustycase

Gutter Rider
May 26, 2011
2,746
5
0
Left coast
Glad to hear you discovered the failure in your driveway!
I would not have been so fortunate.

Sure are a nice looking bike, those PJ's... but like everything else chinamade, the metalurgy is always suspect.

As I noted elsewhere, aluminum suffers from fatigue which can result in spectacular failure. The airlines do their best to cover up this fact.
There is no external evidence of a problem until it occurs.

...and think abt all them homes built w/drywall that ate the piping in the structure! or the melamine enhanced cat food!
My guess is integrity is not to be found in the dictionary over there.

If I had the cccash I probably would have bought one of those spiffy looking cruisers. Just like the Kinks, I'm on a Low Budget...
http://www.youtube.com/watch?v=0HEW5bXqKbU

I'm running 20yr old steel boat anchors that have been salvaged.
Lol wish that were gonna save me! it won't.

Best
rc
 

happyvalley

New Member
Jul 24, 2008
784
1
0
upper Pioneer Valley
Kudos to the OP for the heads up and offering an even-handed assessment on this despite his loss, it's good no one got injured.

Folks should know what they're getting into putting a motor on a bike that is spec'd and made to be passably safe when pedaled at 10 mph.
 
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gooseneck

New Member
Nov 27, 2015
132
0
0
concord, ca. usa
think i'll start dippn' my frame in JB Weld (>:
well better to find out off the bike then head's up from pavement view.
thanx for sharing, somethn' to keep in mind at most times when riding.
 

scrollerguy

Member
Nov 8, 2008
67
1
6
80
Midcoast Maine
FWIW, I, Personaly will never buy an aluminum frame, or a bike with a welded rear rack.

All of my builds have been good old steel, the last one was , you guessed it, the dreaded Cranbrook. Well with over a 1000 miles on it, it has not let me down once.

I recently got one back that I sold a long time ago that was a Kahluna, I know thats got more than my Cranbrook, it has just been jack shafted, and with one of Dax's balanced motor it runs great.

Then there is the bike that I put a Honda GX160 electric start on. I had to stretch and reinforce the frame with 1/4" steel, never a problem.

The Panama Jack, I believe is the same as the Cranbrook, only with a higher price tag, and cheap metal.

Good Luck, glad you weren't hurt.
 

Cgk_iii

New Member
Sep 5, 2013
23
0
1
San mateo
I had a very similar frame to that one, also a huffy. Broke in same exact spot. I remember the distance was very short between the swing arms so I actually ended up bending the swing arms a tad bit outwards for them to fit the wheel, so I figured that's where things went wrong. Not sure if that was the issue or not, but I think the main problem with these frames is that the luggage rack is welded to the swing arm creating hot spots around the welds which makes the metal very weak. They're almost prone to failure with our motorized bicycles.
 

biker61

New Member
Mar 31, 2016
17
1
3
Siloam Springs, ar
I just got back from my beer run.
I had a blast. After exiting Waly World there were about 7 people round my MB taking pictures, and discusing how cool it was. I happily played 20 questions, and handed out my phone number to thouse interested in MB's and this website.
I road home, and looked at my MB with admeration. I decided to start wipping id down, and that is when the words " OH F#%K!!!" came out of my mouth, out loud, in english!!!

I found a full break in the frame, and a 3/4 crack on the otherside. I was one bump away from total failure, and a full blown crash!!!!

If you own a Panama Jack,,, PLEASE look these areas over for signs of stress.My Jack failed in a similar way,mine completely broke through on the other side,I welded it,cut off the rack ,repainted those areas and it's been holding for a while,it is a steel frame on mine
 

rustycase

Gutter Rider
May 26, 2011
2,746
5
0
Left coast
Always disturbing to hear of catastrophic structural failure. It frequently makes the headlines, as we all know...
I am frequently quick to put blame on the integrity of those manufacturers, yet that is not entirely appropriate, considering the nature of the beast.
We expect a people-powered contraption to be lite-weight, yet afford the greatest utility, and of course, style ! :) They, have delivered.
Here, at motorbicyclingDOTcom, have gone the extra mile and modified the engineering marvel of the cantilever frame, with Power Assist ! And this allows us to go farther, faster, and perhaps carry more.
All beyond design specifications.
There is really no fix other than purchase of a proper frame, (perhaps a Worksman?), up to the task.
:) Dip the frame in JB Weld ! Well, that actually might help dampen vibration, if it were applied uniformly and Very thickly... yet not for long.
Some time back I reviewed bamboo bicycles, built by young fellows, probably engineering students, looking for DIY projects. They wrapped just about everything with fiberglass cloth and resin, and it apparently worked well enough.
The same application over one of these frames might actually lend a bit more longevity, yet there would be an end to it, also.
Mild steel, of heavy wall construction will be the best option, in the end.
Never-the-less, I have seen mc frame failure on products from almost every continent, including the heavy-weight American twins.
IMO, detailing a cycle, on a weekly basis, brings personal attention to all elements of the machine, and also affords an element of safety.
Best, rc
 

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,784
26
36
Indianapolis
Yep, Rustycase is right, it's pretty hard to top a quality steel frame. I've owned aluminum alloy bikes (back before I was motorizing) and it's good with the right temper, but it is a totally different metal from steel. Most kinds of aluminum don't well tolerate much flexing, vibration, or shock for long periods of time. There are some higher-end aluminum frames which seem to have tolerated being motorized, but I can't recall which ones; maybe their owners will chime in here.
And don't get me started about carbon-fiber frames. Major temperature variances can cause expansion/contraction-related size differences between the carbon-fiber and metal parts. On a chilly day, you have a real rattle trap. What a motor would do to that, I have no clue. They are designed for, and best left to, pedal power I think.
Modern high-quality steel is a technological marvel. It's been done and proved good for the application. Most of us here already know which steel frames we can trust the most. And although the cheap-steel Panama Jack frames have caused documented breakage failures, even many other inexpensive steel frames have proved usable. Ask around the forum. There are guys here who jump at the chance to brag on their bike frames.
 

Greg58

Well-Known Member
May 1, 2011
5,363
2,590
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66
Newnan,Georgia
My o.p. cruiser is over 5 years old and has a couple thousand miles on it, its a aluminum frame. The 48cc engines have little to no vibration, that may be why I've not had problems. Or it could be that running only 25 to 26 puts less strain on the frame.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
My o.p. cruiser is over 5 years old and has a couple thousand miles on it, its a aluminum frame. The 48cc engines have little to no vibration, that may be why I've not had problems. Or it could be that running only 25 to 26 puts less strain on the frame.

It's the 49cc lack of vibration that makes your story not only possible, but typical. The 49cc motors are MUCH easier on frames and parts due entirely to better overall crank balance and smaller rotating mass.
The 66cc has a high frequency vibration cycle that is BRUTAL on anything flexible and it will bring out the weak spots in any assembly.
Work hardening is the cause of 99% of chinadoll induced failures in fenders, frames, whatever, and it's due almost entirely to the poor crank balance of the generic chinadoll.
The newer 40mm stroke crank pk80's also have much better balanced cranks with markedly less vibration.
Flex almost ANY metal back and forth 200 times a minute and things WILL break.