Straightening a bent chassis......

20K_RPM's

New member
is there any way I can straighten a bent chassis at home without any fancy tools? Like any methods you guys tried that worked? I know if you're doing this way it won't be 'perfect' but I just want something good enough than it is currently.
 

JPMKarting

Premium User
is there any way I can straighten a bent chassis at home without any fancy tools? Like any methods you guys tried that worked? I know if you're doing this way it won't be 'perfect' but I just want something good enough than it is currently.

It depends on where it is bent
 

royberg

New member
We always placed a bucket or a wheel under the front tire we wanted to move up and held down the rear tire on the same side and had someone jump on the the other front tire just be carefully you dont twist it too much.
 

GoFast

Member
I tried that with a Margay Expert-III.
Put one front wheel and the opposite rear on 8" blocks, wedged the other front wheel under the frame of my truck.
That put one rear wheel way up in the air.
Jumped on the air born rear wheel, trying to get the twist out of the frame.
I could bring the rear wheel all the way down to the pavement, and that sucker would just spring back.
Margay made one hell of a chassis back then, maybe still do.

Sold it off cheap. Probably is sitting in someone's garage with an old lawn mower engine on it.
 
Grand daughter bounced left side of champ cart off wall at speedrome bending gage out of square. Chained cart to leg of engine hoist and used bottle jack to streighten, took several tyres but got it close enough to run well
 

Gab507

Member
As stated I use a chain and a jack. You have more control I feel than jumping on a corner, although I have done that. If you are only slightly "tweaked" I would adjust the front with washers first to see if it helps.
 

harrym

Member
It's the front end, it's tweaked. When laying the kart on flat ground and moving steering from side to side.... one side lifts higher than the other. I have a sprint chassis, btw.

This doesn't necessarily mean the chassis is bent. Check rear track and check front end adjustments. Set it up neutral and check again
 

20K_RPM's

New member
This doesn't necessarily mean the chassis is bent. Check rear track and check front end adjustments. Set it up neutral and check again

Trust me, it is bent. There's a pretty sizable difference in height when turning full lock on opposite ends...... just hope I can get it to where it's at least not too bad, I know it won't get back to being squared but any improvement is better than it's current state!
 

Brettm57

Member
I've straightened them by clamping the rear of the chassis to a heavy workbench (It's gotta be really be really heavy!) with the front of the chassis out over the edge of the bench, then put a piece of pipe through the front bumper and with a man on each end twist it back into shape. It's crude but it works. I'd try the "jumping on opposite corners" method first though. You might have to call on a couple of your biggest friends to help with that one!
 

paulkish

old fart
We always placed a bucket or a wheel under the front tire we wanted to move up and held down the rear tire on the same side and had someone jump on the the other front tire just be carefully you dont twist it too much.

ditto
 

XXX#40

2A supporter
Trust me, it is bent. There's a pretty sizable difference in height when turning full lock on opposite ends...... just hope I can get it to where it's at least not too bad, I know it won't get back to being squared but any improvement is better than it's current state!

is the chassis bent or is it the spindle?
 

01ron

Member
Just a thought. It sounds like you are saying the spindles are at an even height when the steering is centered but raise/lower at different rates when the steering is turned. Sounds like a caster issue. Did you check that you do not have a bent king pin. If not, you must have a twist in your "C" clip on one side.

You don't have a caster/camber pill that is set different on one side than the other?
 

XXX#40

2A supporter
We never straightened a chassis, once bent and bent back you change the flex properties, the area it bent and bent back becomes work hardened,
old chassis are cheap, youll always wonder about it, might be better just to find another bare chassis and swap parts over
 

Menace61

Member
I used a hydraulic porta power to straighten mine. Won six out of nine starts after straightening it. The guy that has the kart now loves it. Doesn't hurt to try it. Better than throwing it away.
 

Jimbo

You can fool some of the people some of the time
I'm dealing with a sprint chassis right now.
With all the spindle washers pushing the left spindle down as far as possible and the right spindle up as far as possible it's still 30 pounds light on the left front wheel. It's way off on the rear also.
 

harrym

Member
We never straightened a chassis, once bent and bent back you change the flex properties, the area it bent and bent back becomes work hardened,
old chassis are cheap, youll always wonder about it, might be better just to find another bare chassis and swap parts over

One bend doesn't work harden 4130 material. So what you're saying is when I bend a piece of 4130 tubing in my bender that that piece is now work hardened and won't flex? I straighten 3-4 chassis sometimes in a week. I have a few customers who have an arrive and drive business. After I straighten then , they are as good as new. I built a special fixture to do just kart chassis. Some European chassis I don't mess with, they are soft material and have no flex. That's why Tony Kart and several other Euro builders race them 3 races and throw them away. The tubing has to be bent slow and steady, That's why I tell everyone....do not jump on them. I've saved a lot of people money by straightening their chassis. Not everybody is Big Daddy Bucks as yourself and can buy new chassis.
 

BMB

Member
I agree harrym, I straighten 3-4 chassis a week euro or American they all bend. They can all be straightened. I have a 2500#steel plate table can do anything I want with a chassis.
 

XXX#40

2A supporter
One bend doesn't work harden 4130 material. So what you're saying is when I bend a piece of 4130 tubing in my bender that that piece is now work hardened and won't flex? I straighten 3-4 chassis sometimes in a week. I have a few customers who have an arrive and drive business. After I straighten then , they are as good as new. I built a special fixture to do just kart chassis. Some European chassis I don't mess with, they are soft material and have no flex. That's why Tony Kart and several other Euro builders race them 3 races ?and throw them away. The tubing has to be bent slow and steady, That's why I tell everyone....do not jump on them. I've saved a lot of people money by straightening their chassis. Not everybody is Big Daddy Bucks as yourself and can buy new chassis.

so when you bend steel you dont change the molecular structure?
um we are talking about bending it 3 times not once, not including all the flexing it had done before it was bent
 
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