Forks bent, how bad is it?

Time will not make any difference... You will have to plastically deform the material past its "elastic" yield point to correct its deformation... Permanent deformation will not occur until you take the materiial past its yield point, with that being time independant...

Yeah, one second, one hour, one day, one week, one month, one year, one decade, one lifetime, it's all the same.

Scott
 
Following. Use magic marker to keep track of which way the bend "was". Like others said you have to go past to "deform again" the bend is not in "one place" your straightening shouldn't be either. Better to work down about 6" of the tube in say 2" increments bending back back a bit at each station. Generally the bend will start just below the lower triple, extending down a bit. Tubes don't just bend they go oval. Bending back the other way tends to increase the oval. chucking between centers is a good way to see and mark the bend.
 
The forks set at an angle as you ride down the road. As the bike rides over bumps the forks flex upwards. This flexing actually bends the forks. A little bit at a time.
Maybe it's back the flex goes not up, but you get the idea.
Find a dirt bike shop, they fix bent forks all the time.
Leo
 
It's tough enuff to straighten fork tubes in a press with jigs and fixtures. When you view forktube assemblies on the bike, you see dual support from the trees at top, and tubular reinforcing from the sliders at the bottom.

So, when fork tubes get bent, they tend to bend in a 'V', in that short unsupported zone between the bottom triple and slider top.

Setups for straightening in the press normally confine all forces between those two endpoints, the bottom triple and the slider top, about 5"-8" worth of fork tube between the supports. Hence the need for a stout press, and focusing the press forces to the peak of that 'V', leaving the normally-still-straight ends out of the picture.

Trying to press out that 'V' with the fork tube supported at the ends usually results in a squashed 'W' shape, and the tube may bind in the lowers...
 
But the thing is, where is the bend..............If its 1/3 rd of the way down the tube then the supports have to be an equal portion in distance away from the center where the bend is, not at each end of the tube

It's tough enuff to straighten fork tubes in a press with jigs and fixtures. When you view forktube assemblies on the bike, you see dual support from the trees at top, and tubular reinforcing from the sliders at the bottom.

So, when fork tubes get bent, they tend to bend in a 'V', in that short unsupported zone between the bottom triple and slider top.

Setups for straightening in the press normally confine all forces between those two endpoints, the bottom triple and the slider top, about 5"-8" worth of fork tube between the supports. Hence the need for a stout press, and focusing the press forces to the peak of that 'V', leaving the normally-still-straight ends out of the picture.

Trying to press out that 'V' with the fork tube supported at the ends usually results in a squashed 'W' shape, and the tube may bind in the lowers...

It is about a 1/3 the way,

attached a photo of my prototype! I was able to tighten it just by hand to slightly past true in the opposite direction, it will most likely just spring back to bent... but i'll leave it in over night and see it its any straighter...

Pic in post #18 goes against what was suggested and what you said.
 
I have not corrected any of the bend yet, photo was just to show how it works and if I could get enough tension with this system. I will work out where the bend starts/ends and where the middle is, high point etc. Thanks for all the info so far guys, I will probably try the bend, and if it doesn't work out ill get new tubes or take them somewhere.

And actually it is closer to the center, maybe 2 inches or so off center.
 
Usually in my experience when I bend something back to straight, you have to go beyond the point of straightness. If that makes sense. The object tends to wonder back. There is a very fine line here. You can go too far and be in different situation.
 
that's what scares me about using the jack technique, I totally see myself turning my tube into a kinked garden hose haha.
 
Usually in my experience when I bend something back to straight, you have to go beyond the point of straightness. If that makes sense. The object tends to wonder back. There is a very fine line here. You can go too far and be in different situation.

Yes, can be tricky. You have to press quite a distance, to get past the metal's elastic stage, into the yield zone, and then past that by the amount of correction. Finding that yield zone can be maddening...
 
finally found a shop in Calgary "old motorcycle shop" great guys. Brought it in and they straightened to less then 6 thou, for $60! I called about 10 places before that said they don't do it.
 
Back
Top