Author Topic: JFab frame rails breaking  (Read 30863 times)

0 Members and 1 Guest are viewing this topic.

Offline Extreem

  • Jr. Member
  • **
  • Posts: 29
Re: JFab frame rails breaking
« Reply #30 on: September 01, 2012, 03:25:31 AM »
I wonder if JFab is going the way of Stewart......
This post has been active over a month with no reply from him ???

Offline jBernard

  • Sr. Member
  • ****
  • Posts: 299
Re: JFab frame rails breaking
« Reply #31 on: September 04, 2012, 11:44:44 AM »
as noted before, guy is super busy and i doubt he is ignoring this thread if he has seen it by any chance.

there are to many other factors to put blame on jfabs rails. yoke design, welding expertise, swingarm thru bolt squareness, head bracket design to frame, ect.
people bend aluminum tubing every day and put structural loads on it. jfab's rails arent bent with any crazy angle, so i'd be looking to other stresses as the culprit as of now.
'09 KX500AF - never ending project
'14 KTM 300SX

Offline sandblaster

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8,271
    • OEM-CYCLE QUALITY USED PARTS
Re: JFab frame rails breaking
« Reply #32 on: September 04, 2012, 02:12:30 PM »
I'm with you jBernard.
As a business owner I know that responding to every potential complaint can be tedious and time consuming.
I'm certain that this thread has been on his mind but think about it this way.
What can he say that will prove or disprove the concerns raised here?
Have you ever heard of any of his frame conversions failing?
I haven't, but like many others I chose to try it myself because I was too cheap to pay for a first class job and I wanted to see if someone as inept as me could do it.
Remember he does not make the basic material.
All he does is cut it and bend it.
It is up to you to know what you are doing and do your own engineering (Not WAG engineering).
If you run a stress analysis on the material you will see that it is more then enough material to handle the load providing that the load is correctly divided on it's mounting points and providing the head stay is properly engineered.
From the pics I saw there are problems with that design.
I'm not sure that comparing this situation to that of Stewart is really relevant.
I'd like Stewart to sign up under a different name so he can provide his technical expertise but, I would not buy from him :-)
I will be doing another conversion after I get my current one done and I will buy another set from Jfab  :-o
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline Starky307

  • Jr. Member
  • **
  • Posts: 21
Re: JFab frame rails breaking
« Reply #33 on: September 04, 2012, 07:44:26 PM »
I'm with Sandblaster, there was/is nothing wrong with the frame rails. It was the design of the headstay that caused that failure.

I don't know jfab nor have I ever had contact with him. I can't stand seeing an internet flaming or lynch mob in action when there is absolutely no need for it.

Can someone put this thread to bed, I think it is terrible that there are people trying to put blame towards the person who bent the rails and not that of the person who didn't know what they were doing when they made the head stay.

Rant over.

Offline don46

  • Hero Member
  • *****
  • Posts: 1,140
Re: JFab frame rails breaking
« Reply #34 on: September 05, 2012, 07:30:38 AM »
I wasn't going to post on this topic but in the end I see a good person being slammed. there was nothing wrong with the frame rails, there are many people on this site using them. What does that mean, it means that the installer failed to make a proper installation. What is it that those of you keep saying where is Jfab want him to say? he bent rails and the consumer installed them, so figure out what your problem is and fix it.  It is so easy to right away blame somebody else for our mistakes. I think that it is a matter of time and you will see more break, not because they are weak but improperly installed. I had a set fail (not Jfab's) and upon reflection I re-designed my installation and haven't had one problem (I did a 250 and a 500). Remember the 500 vibrates alot, how many have broken mounts on their steel framed bikes, so the AL will probably break as well unless you have a well balanced motor.

So lets stop asking where Jfab is and fix the underlying problem, and when you do let the rest of us know how you did it so we can re-enforce our designs.

have a good day!
Live today, for tomorrow may never come

Offline Dutch-K5 Fan

  • Hero Member
  • *****
  • Posts: 759
Re: JFab frame rails breaking
« Reply #35 on: September 06, 2012, 03:47:22 AM »
I wasn't going to post on this topic but in the end I see a good person being slammed. there was nothing wrong with the frame rails, there are many people on this site using them. What does that mean, it means that the installer failed to make a proper installation. What is it that those of you keep saying where is Jfab want him to say? he bent rails and the consumer installed them, so figure out what your problem is and fix it.  It is so easy to right away blame somebody else for our mistakes. I think that it is a matter of time and you will see more break, not because they are weak but improperly installed. I had a set fail (not Jfab's) and upon reflection I re-designed my installation and haven't had one problem (I did a 250 and a 500). Remember the 500 vibrates alot, how many have broken mounts on their steel framed bikes, so the AL will probably break as well unless you have a well balanced motor.

So lets stop asking where Jfab is and fix the underlying problem, and when you do let the rest of us know how you did it so we can re-enforce our designs.

have a good day!

I have made a AF my self with some advice from Jfab and AJ Wagner from service Honda. Frame braking is always on my mind (especially now) but if it does. It's my problem. This these is like the prox, wossner, wiseco piston topics. Give the product you used the fauld, not who installed it. Jerry Jfab has been "away" for a wile like me, maybe even longer because of to much work and others.
I trunned my crank with zero tollorance when I rebuild my engine this summer.
Helped allot with vibrations. And also remember that we do things that wasn't ment to be. Kawasaki R&D for months, we once and than race it!!!!

Dutchie
Proud owner of a KX500AF

Motorrad

  • Guest
Re: JFab frame rails breaking
« Reply #36 on: September 06, 2012, 04:16:01 AM »
Like everyone said... the rails arnt to fault.


Jerry even told us he would be away for a while.    as his shop had #1 priority.  Not like he slithered off into the bushes, he told us!!     

I debated removing him from the vendors at that time, but my conclusion was..

why ?

you can call him on the phone, and he answers, and provides his product that way...        if I removed him, then no one would know of these products, that make their AF conversions that much easyer..   

I know if I was doing one, Id want to know about some guy like Jerry providing parts.   even if I had to pick up a phone to get them, not just send a PM.

have any of you actually called him and asked him about them breaking?

Offline maddoggy

  • Hero Member
  • *****
  • Posts: 711
  • K5 @ ST. ANTHONY DUNES
Re: JFab frame rails breaking
« Reply #37 on: September 13, 2012, 04:50:55 AM »
i don't blame jfab one bit for the rail failure, i would just like to see his input and what his advice would be. does he already have measurements and proven angles in mind? just a quick, hey this is what i think happened and here is what i would do differently on the design.

Offline SS109

  • Full Member
  • ***
  • Posts: 92
  • KDX fanatic!
Re: JFab frame rails breaking
« Reply #38 on: September 15, 2012, 02:31:24 PM »
FWIW, I know I won't hesitate to buy and use his rails when I start my conversion.
'90 KDX 200 (rebuild - DONE!) - '94 KDX 250 (soon to be a KDX250af)

Offline Extreem

  • Jr. Member
  • **
  • Posts: 29
Re: JFab frame rails breaking
« Reply #39 on: September 16, 2012, 12:07:47 PM »
i don't blame jfab one bit for the rail failure, i would just like to see his input and what his advice would be. does he already have measurements and proven angles in mind? just a quick, hey this is what i think happened and here is what i would do differently on the design.

Exactly...I don't care how "busy" he is.  He is on this site almost daily.  I'm not saying his rails are bad, i'm sure it was a bad install. ....but based on the lack of any response why would any one feel comfortable doing business with him? 
« Last Edit: September 16, 2012, 12:11:42 PM by Extreem »

Offline jBernard

  • Sr. Member
  • ****
  • Posts: 299
Re: JFab frame rails breaking
« Reply #40 on: September 17, 2012, 01:26:31 AM »
daily?
just for clarification last time he was on this site was over 2 wks ago and it was at 1AM.

i think you may be putting to much emphasis on JFabs rails for this guys complete build. Jfab just bends the aluminum rails. and from what i know about bending square tube, he has a pretty nice machine to have the radii looking like that, so its definitely not a hack job.
jfab doesnt make the motor mounts, he doesnt make the headstay, he doesnt make the yoke, he doesnt weld, he doesnt fit, he doesnt give instructions on the fab work. we havent singled out what the issue was that caused the problem, so calling out 1 particular thing is jumping the gun a bit i think.
« Last Edit: September 17, 2012, 01:46:27 AM by jBernard »
'09 KX500AF - never ending project
'14 KTM 300SX