Is my fork Bent?

Fings369

Fings369

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How can I go about checking for any kind of bends in the front end?

It has an odd lean~ish stance when I'm rolling it
I've heard of pulling the fork tubes out and rolling them on a pool table or something of sorts

any tips? tricks? :shrug:
 
The best way to check for tube straightness is to remove the forks, disassemble the tubes from the forks then roll them on a flat surface while watching to see how much the middle and ends lift off the surface.
This might be hard to see on a pool table, the knap of the felt will hide small bends.
A thick sheet of glass or a steel table top would be better.
It may b e the forks or the trees. The lower tree can get bent in a crash.
To check remove the forks and trees. set the lower tree on a flat surface. Are both sides where the tubes go through setting flat on the surface?
Leo
 
35 year old bikes, a crash in the bike's history is quite common. Many repairs are of the "fix it good enough to sell the bike" variety.

First off check that the rear axle is straight in the swing arm are both sides the same number of hash marks from the front?

Then bent tubes.
bike on the center stand or blocking under the engine.
remove front wheel and fender. Place just the front axle in the tubes, don't tighten it. Loosen the three bolts that connect the ONE tube to the triples. Hit the triples with a bit of rust buster. You can grasp and rotate the tube in the triple. the lower should not move about on the axle. if it wobbles you have a bent tube. Retighten those bolts, loosen the other side, repeat. Now remove the axle. drop the loose tube out of the top triple a bit , slide it back up into the triple, it should line up with the hole no twisting or forcing should be required. If you have to force a tube to line up, the lower triple is bent. they can be straightened if the bend is not severe. Finally if the collision was hard enough the frame neck may be bent. about all you can do with the bike together is eyeball the front wheel against the engine see if it appears centered. Good luck and please tell us your findings.
 
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If you have both tubes disassembled, try rolling one against the other on a table turning the right one counter clockwise and the left one clockwise.

Very important. ha ha

That will show the bends.
 
What's the significance of the direction of roll? would a bend be easy to see sorry just don't get the clockwise reference
 
No no Fings, just joking. ha ha

Rolling one against the other, if they are slightly bent, will show double the error when both bends get aligned up making it easier to see small bends.

Play with them and you'll see what I mean.
 
so I came home for lunch pretty sure its bent all to hell can't get the forks parallel in the bottom tree to the wheel
 
Now I need to figure out what's safer, rebuilding what I have if it's not entirely shot, or taking a chance on a few sets they have on fleabay that could be bunk as well....


Guess? Offers? Beer?
 
Start checking, see what parts are fubar. The triple really is pretty easy to straighten. Yeah used triples are a crap shoot.

:cheers:
 
The triple is good and flat, but the tubes are squirrely, do I need to replace the lower halfs or should the bend be limited to the fork tubes themselves??
 
I'm thinking its the lower triple tree that is bent. My bike had been in a front end collision, and the lower triple was bent. Set the triple on a plate of glass,and you may see that its bent.

The lower triple is steel, so it can be bent back straight again. Forks were clamped to the tree, and I used a 2 x 4 to twist the forks. Re-test on the glass to know when its corrected.
 
Haven't tried these but much less than forking by franks tubes....

MikesXS

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Standard length 35mm. Fork Tubes fit All 1977-84 650's. 23" long

#27-3002 Replaces OEM #'s : 2F0-23110-00, 1T3-23124-50, 1G3-23124-50

OEM Reference #
• 1G3-23124-5-00
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So got into it some more and I think the triple tree is fubar something like a little less than a mm off of glass and if I rock it the other bracket doesn't stay flush, also had to gently persuaded it to come off and my front wheel is running shmarley tires ??
 
Does anyone have a reference for how much bend is acceptable? when i roll mine on the table saw top (flattest thing I have) i get maybe 1/16 inch daylight in one spot. Also, what type of shop can straighten them? thanks in advance.
 
The bend will only affect the alignment if it is for or aft. Turn the fork tube so the bend is to the inside or outside and it will not be noticeable. Inside is better as the result squeezes the axle.
 
Sorry Pete but I beg to differ. IMHO forward is preferred. If it's to the side the distance between the tubes will be either more or less at the axle than it is at the triples. This results in (possibly severe) fork binding.
 

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