Need help using a VAR Fork threading tool

[alainbriot]

I bought a VAR Headset fork threading tool on ebay. I got a good deal on it, problem is I can't find out how it works. This is an older, vintage tool, however VAR is a reputable brand so it should be designed to do its job.

The tool should have an expanding screw to make the tap die wider or narrower but the screw that's in it right now has no effect. It does not widen or narrows down the die. I tried on an unthreaded fork, 1-1/8" diameter head tube, and it does not go over the tube even though it is marked 1-1/8 and 26 pitch which should be for 1 1/8 steerer tubes.

The main problem is I can't get the thread started. The tool won't go over the the steerer tube. I am getting ready to return it but it may be that I just don't know how to use it. I attached photographs. I suspect this may be rookie error. I have never used a fork threading tool so this is my first time trying to thread a fork steerer tube.

 

[Midlife]

It's been a long time since I tapped a fork thread but the one we had in the bike shop had a taper on the die leading into the threads, take the die out and see if it seats over your steerer. ?

There are quite a few frame builders that post on lfgss if nobody crops up here.

 

[alainbriot]

Thank you. I tried taking the die out and it is smaller than the steerer tube.

Maybe that's the way it is designed to work?

 

[My_Teenage_Self]

there's no way it should slip over the steerer, but getting threads started is hard (And a steerer is a BIG thread). A chromoly steerer is a tough material to start too.

Have you ground/filed a chamfer in to the steerer to help it start? You'll need to make sure it starts square to the steerer which is also a challenge. Finally, are you 100% you have a cutting die and not a chasing die?

 

[mdvineng]

Re:

Pic 2 shows the part that goes over the steerer first, which guides it centrally and square to the tube.
Pic 3 shows that the die is upside down, the detail info should face the cutting to be done and there is a split in it that needs positioning with a grub screw that has a 90 deg point to it, as that is how the adjustment is done to obtain the correct size.

 

[mdvineng]

https://youtu.be/9lI9-wyrubE

 

[Peachy!]

Re: Re:

Pic 2 shows the part that goes over the steerer first, which guides it centrally and square to the tube.
Pic 3 shows that the die is upside down, the detail info should face the cutting to be done and there is a split in it that needs positioning with a grub screw that has a 90 deg point to it, as that is how the adjustment is done to obtain the correct size.

Looks like it’s been sold to you with a replacement grub screw, even so, as per advice above try flipping the die over and chamfer the top of the tube, a good cutting compound should help as well.

 

[The History Man]

Have you got an aheadset type threadless stem you could slip over the steerer to use to start it square to it. Then use it as a guide as you go?

 

[alainbriot]

Re:

Thank you for all the suggestions. I'll flip the die over, cut a chamfer (I have not so far) and try the other tips. The grub screw looks like it serves no purpose as it is now. Shouldn't it be fluted, meanting larger at one end than the other? Pointed at 90 degrees as you say. Mine is straight, same diameter throughout.

How can I tell if I have a cutting die or a chasing die?

 

[Midlife]

Does picture 2 show the chamfer on the inside of the die to help guide the die in the tube? BITD we used a lot of oil, we also used to cut a quarter turn at a time and back out, just out of curiosity has it changed ?