# Cutting down forks



## the tinker (Oct 9, 2015)

Buy a girls fork for your bike......and it's too long 
Here's how to shorten it and re-thread.
The fork being shortened is a 1930's girls shockmaster to fit in the Hawthorne 5 bar I bought last Sat.

I removed the girls steering tube and placed it next to a boys.  you can see how much has to be removed.
 The first step is to figure how much you need to remove. the best way is to measure a boys fork that fits or taking your girls fork and placing it into the frame you are going to use and mark it in place where you will make the cut. Allow for the all the hardware that goes on your particular fork.   Don't be caught short! Make sure the cups and bearings are in place when doing this. 

If you are cutting down a Monark,Shelby, Columbia or post war cleaveland welding take a headset nut and thread it down to the point that it will be cut off at.  Using the nut as a guide use a hacksaw to evenly cut off the excess.[see photo] and remove nut. There will be some threads left on these type forks to start your die on.

In the case of the pre war shockmaster it is much longer so I placed it in a pipe vise and used a pipe cutter to insure an even cut. 

Then place the steering tube in a vice and firmly start your die cutting into the fork tube.
Use plenty of oil. liberally oil on each complete turn. Notice the oil that dripped into the rag on the floor.  Not enough oil and you may ruin your die.

when you are down far enough ,back off continuing to oil as you unscrew the die.

Next use a dremel to cut the keyway.

If your springer has truss rods as this one has the bottom of them will have to be shortened.
Basically the same process as the steering tube X 2.

On Monark forks the front fork that supports the springs will have to be shortened and re threaded. just discard the two chrome spacers afterwards.

Monark and shelby will use their existing yoke.  Columbia 's yoke will need to be replaced with a boys.
 On The 53 54 monark  and huffman springers  the fork arms and truss rods are too long so cutting them down is not an option.

The pre war single upright hawthorne and postwar rollfast springers have a different size spring for boys and girls forks. 

Last resort is to cut off {see arrow on photo] the fork tube and replace with one from another fork as shown. Notice the weld bead about an inch from the bottom. If the fork tube is too badly damaged this may be the way to go. The two pieces must be exactly aligned. 
something[pipe... bolt... whatever] must be inserted into the fork tube at the joint.This will hold it straight and give some backup for the weld. Has to be no more the an inch from the bottom of the fork tube or your stem will not go all the way into the tube at handlebar time.
 Be sure to have bottom stationary cone on before you weld together.




 
I have these photos a bit out of order here but I think you get the idea]  Have fun!


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## bricycle (Oct 9, 2015)

A very well done tip.


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## the tinker (Oct 9, 2015)

After posting the photos of cutting the fork down I went inside, read today's paper [nothing good there] and ate a nice lunch. 
Afterwards put the springer together and everything fits nice. The hunk of pipe I cut off is on the top right of photo.
Went down to the hidden parts bunker beneath Colson Command Post and found two New old stock springs!! 
Now I want to put it on the bike and the wife just came out to Colson Command and wants ME to clean the BATHROOMS!!!!! ......RIGHT NOW!!!!!!!

"Bathrooms? we aint got no bathrooms"

I aint cleaning no STINKIN BATHROOMS!!!!


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## bricycle (Oct 9, 2015)

that and yard work are my primary jobs... oh, and repairing things....


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## WES PINCHOT (Oct 9, 2015)

Thanks for sharing Tinker!


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## mikecuda (Nov 18, 2015)

Outstanding DIY tutorial.   I'm dealing with a 28" prewar frame and several fork tubes that are all different.  I will select one based on your guidance and make the move.   Thanks!!!


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## rusty.kirkpatrick (Dec 5, 2015)

what size dye is that exactly?


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## the tinker (Dec 6, 2015)

rusty.kirkpatrick said:


> what size dye is that exactly?




I inch- 24 threads per inch .  they are available on some of the tool sites, also have seen them on Ebay.
Will need a Die handle .  The smaller dies for the truss rods are available from Vermont tool. Ace Hdw. will have them. Don't need a die handle for the newer ones as a wrench will fit them. Use plenty of oil when using.


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## ram.1950 (May 31, 2016)

I've converted two girls shockmaster forks to boys - I take mine to my LBS and he threads the fork tubes down for $5.00. If I did a lot more of them it might be worth buying the tools to thread the fork tube myself.


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## bairdco (Jun 1, 2016)

Old thread, but...

I have a steertube die, so I thread it down as far as I need, put the fork on the bike with cups, bearings, etc, except for the top nut. 

Eyeball the length of the top nut, mark it, then thread an old cone nut down for a guide, and chop it off while on the bike with a portable band saw.

File it a little, use a washer that doesnt have the tab in it so I don't need the slot, and put the nut on and ride it.

For welding a new steer tube on, I chop it off near the bottom, drill a small hole thru the tube, and thru the new steer tube, get a solid rod an inch long that fits snug in the old steer tube, sticking out a half inch, put the new steer tube over that, leaving a 1/16" gap, then weld the gap and the holes up.

Grind everything flush, so you can still get the race on and off.


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## 1938airflow (Oct 15, 2016)

Has anyone ever cut a girls fork steer tube off and weldEd another tube back on.

I have a girls shock ease steer tube and need to cut down to make a men's but the steer tube has a lump where it need to be threaded. If I try to cut the treads down will the die brake or push the lump back down?? Or should I just cut the tube off in the middle and then cut a men's fork threads off and weld it back together where it needs to be???? Someone help me out if they ever had this problem.
The only reason I'm going though this much work is because I can't find a men's shock ease steer tube!!!!!!


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## the tinker (Oct 15, 2016)

I bought a J.c. Higgins springer that someone before me had slipped a pipe over the end it to use as leverage to straighten out a bent steering tube. they sorta got it straight but they ruined the threaded end . Looked like and oval. I heated it up with a torch and beat it back into round. Did not look perfect. I re- threaded it. It took the fork nut with no problems.
After you heat the bump, hammer it back in. Do not "cool" it off with cold water as that will temper the steel .Re thread with your die with plenty of oil and should be ok.
As far as welding a new tube on I have never messed with the shock ease fork. Usually the fork is cut about an inch off the bearing race and welded as not to have any weld slag or bead that may be on the inside of the tube interfere with the installation of the stem.


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## ricobike (May 24, 2018)

Special thanks to @the tinker for this excellent How-To.  I've had the tools to do this for a while now, but never needed to do it.  Well, Ann Arbor this year gave me a girls bike that was a perfect match for my Westfield Paratrooper so it was time to get the hands dirty.  I was challenged by the fact that the fender didn't want to come off so I was going to have to do it with the fender on.  I came up with a mod to my workbench where I could temporarily bolt my pipe vice horizontally on the bench which solved that problem.  I could have done it either way that tink described but I was worried that if I cut off the headtube first, I would have trouble getting it to thread straight when trying to thread from scratch.  I did a test on a junk head tube and turns out I was exactly right, it was skewed horribly.  So I decided to go the long route and use the threads that were there to help me thread it down straight.  Worked awesome, here's a few in progress pictures and a final result.  Thanks tink for an excellent writeup, I referred to it a lot while I was working on this.


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## the tinker (Dec 22, 2020)

A question was asked to me recently about re-threading and cutting down forks, so I will clarify it in this post.  The easiest and cleanest way to cut your fork after threading it, is to screw the bearing nut down to where you will make your cut. Use the "flat" of the nut as a guide for your hacksaw blade. Don't be in a hurry, always cut it by hand.  After it's cut to length, don't take the nut off.  Screw the cap nut down a bit. Take a fine flat mill file and slightly , [ very slightly] bevel off any burrs left from cutting,  and knock off the sharp edge on the start of the threads. Back off the nut, it'll clear the threads. You're done.  You don't need to buy any special tools to cut it off. Always re-check your measurement before cutting. It's a good idea to store unused forks with a nut on the end. I've bought lots of forks at swaps with dented ends from careless storage. They have to be re-threaded. I was cutting down a Monark fork today and thought I'd add this info and photos to my old thread.


Thread it.


Mark the length.


Thread the nut down to where you want. Secure in your vise and cut, using the nut as a blade guide. As always, have fun and remember: This is only a hobby and they're only bikes. Make it fun my friends. On double forks, like the twin spring Monark, or forks that have truss rods, cut a like amount off them.


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## RustySprockets (Dec 22, 2020)

I've been known to collect hardware from the co-op's scrap pile for this express purpose.  A nut with pitted races does this job just as well.


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## frankster41 (Dec 23, 2020)

Great tutorial Dave as I have done the same fixes many times!!!!


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