# So I made a fork jack...



## bikemonkey (Mar 31, 2017)

Most of the shops I worked in back in the 70s and 80s had a fork jack to straighten forks damaged in T-bone collisions. Now I am back on the bench again, I knew that sooner or later I would need one.

When this '59 Jaguar came in for restoration, the owner related how he nailed a ditch at the bottom of a hill and his bike rode funny afterwards....ya think?

I could not do this resto without repairing or replacing the fork. Repair was my first direction as I knew paint matching this faded fork with a replacement would be difficult. Also, the long pinstripes on the fork blade are terrific and I don't even want think about replacing them.

I realize that bending forks is not optimal and I informed the customer about the risks of the fork separating at the crown, either during the repair or under stress later. I was told the risk was acceptable to them and try repair first.

Called a couple of shops about 30 miles away but nobody 'round these parts has a fork jack, so I made this one with a $17 jack from Harbor freight and a spare 2x4. I wanted my own for the shop anyway. The construction design was something I did after thought experiments when driving back and forth to Raleigh last week.

Finally, something I made out wood actually came out ok and worked the first time (you should see the crappy bookcases I have made in the past).

So, if you need a fork jack, just go make your own!

Construction notes:

I drilled holes in the metal base plate of the jack and attached it with screws to the wood base plate. The two 2x4's are spaced in the center with a few 1.25" wood block spacers so the supports just fits around the down tube at the bottom bracket. I also made slight semi-circular cuts in the supports at that junction so they would not slip off the bb shell under pressure.

The wood supports are nailed together with large nails that pass through drilled holes in the spacers.

I used a dummy axle up front with a cut off handlebar end as a spacer to distribute pressure all along the axle. I flattened the bar spacer on a small section on one side in the middle so it would rest squarely on the metal jack tip.


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## catfish (Mar 31, 2017)

Good idea.


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## bikecrazy (Mar 31, 2017)

I'l bet it didn't take much pressure to bend that fork back into shape.


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## Andrew Gorman (Mar 31, 2017)

And no welding required!  Makes it easy for us city folk.


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## bikemonkey (Mar 31, 2017)

bikecrazy said:


> I'l bet it didn't take much pressure to bend that fork back into shape.



Nope...it was very smooth. Back in the day it seems my stress would ratchet up with each click of the 'ol car jack.


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## PCHiggin (Mar 31, 2017)

Great idea


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## ricobike (Apr 5, 2017)

Great minds think alike 

http://thecabe.com/forum/threads/fork-bending-tool-mystery.84362/


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## bikemonkey (Apr 9, 2017)

ricobike said:


> Great minds think alike
> 
> http://thecabe.com/forum/threads/fork-bending-tool-mystery.84362/



A friend of mine showed me this pic during my discussion with him about my thought experiments and I am like "Have I seen this pic before?"...still don't know....I am certainly not claiming to reinvent the wheel...lol

I stuck with my design which I think is a bit cleaner but it shows the need of bike mechanics everywhere to have occasional access to this type of tool.

I had previously searched for an old ratchet jack a few months ago when I was at a salvage yard. I was going to try and make one of the old school type fork jacks - glad now they did not have the old jack.

The hydraulic jack gives you much better control over the alignment process. I am going to screw metal T braces on each side of the wood base plate/long struts so it will strengthen it in that area.


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## ricobike (Apr 9, 2017)

I did something similar last month making a Schwinn kickstand removal tool.  Had to get it done and was real proud of my solution (c-clamp and cut piece of seat post) only to google and find that everybody and their mother has thought of it at some point .  It's all been done before, but kudos to you in thinking of hydraulic jack for a fork jack.  It is an elegant solution.


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## Thonyv1974_ (Apr 14, 2017)

I straightend one by using a beater wheel and turning fork backwards and ran into a wooden phone pole til it was straight. Crude but it worked well. .. really like your way better.


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