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Straightening a bent fork using a table saw!!??!

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Hastings

I live for the CABE
I did this early this morning.. worked really well. Not sure if this method was posted before. I felt it was really safe and forces were easily controlled.

Need: 2pieces of 1” thick soft wood, 1 piece hard wood, couple shims, table saw with cast iron top, c clamp or pony clamp. All things most people have laying around.

Unplug saw. Drop table saw blade below flush, remove the safety cover, Bridge fork over the saw hole using the 1”soft wood, place fork with arching side of fork facing up. Put hard wood on top side of fork. Place clamp between bottom of cast iron top of hard wood. I cranked it 1/8th turn every ten minutes just to be safe and not anger the sleeping old fork. Going with 1/8 turns and creep up to the fork being roughly straight. Take it off. Look to see if one of the legs is a little behind where it should be. Clamp down again but shim that side. Repeat till twist is gone. Reclamp it again but now with no shims. Go slightly past where you want it. Leave it clamped>go clean some hubs! Half hour or so later remove. Here’s some action pics. I’ll post the “before & after” pics tonight or tomorrow once I get the bike back together. Comments and suggestions always welcomed.

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With a set up like this, you have to be careful not to flatten the steerer tube or fork blade tubes where they press against the wood blocks. A heavily built fork with thick walls against blocks of soft wood (pine maybe) might certainly work, and it's a nicely simple set up if you can do it that way.

But on some forks, unless you cradle the rounded parts of the fork with contoured wood, you risk putting a flat spot in the metal tubes where they push against the flat blocks. I'd hesitate to put something like a 1970s Raleigh fork, or anything with thin-wall 531 alloy on flat blocks like that, but an old timer fork that is heavily walled may certainly respond better to the flat blocks. Parktool's old fork jig uses a diamond-type cradle for the steerer tube to avoid this problem, though the old timers also had a tool called a "pipe vise" that similarly could cradle a round piece.
 
I use Park Tools FCG-1 fork alignment tool, then just tug on the fork legs to bend them up or down as needed. Can take a good bit of force, but seems to work pretty well. If its the steer tube thats bent near the crown, I just clamp the tube ahead of the bend and give it some force.

There's a newer version that has a squared off clamping die and is lighter duty... forget that one, try to get the good older one if you can.


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I use Park Tools FCG-1 fork alignment tool, then just tug on the fork legs to bend them up or down as needed. Can take a good bit of force, but seems to work pretty well. If its the steer tube thats bent near the crown, I just clamp the tube ahead of the bend and give it some force.

There's a newer version that has a squared off clamping die and is lighter duty... forget that one, try to get the good older one if you can.


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That's what I use - it's an excellent tool. I wish they still made stuff like this, but it's secondary market now because many shops just don't straighten forks anymore.
 
That’s great. I didn’t even know that existed. I saw something on here about using a car jack with the bike upside down and I didn’t like the looks of that. I just went with what I had on hand. Worked pretty good but that tool is definitely on my list. Thanks
 
Those look like good frame blocks. I may pick up a couple sets and see what they can do. They are aluminum, but maybe they will still compress the steel tubing fine. Two things that I have seen come up more than once are slightly bulged steerer tubes (probably due to over tightening the stem) and slightly oval-ed seat stays due to over tightening generator or tail light clamps. I've never done much to either, so long as the deformity is not extensive. But it's nice to be able to press them out and get back to correct shape.
 
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