Internal fork stop kit

[Turbodog1000]

How the fudge do u install this thing. I got this neck cup kit for my chop but it came with no instructions...

[MOTher]

Depends on what you're putting it on. Whatever it is, you need a flat spot on the lower triple tree around the stem big enough for the slotted piece to sit. I'm putting one of those kits on an older 35 mm tree that does not have a flat spot, so I'm having one machined.

If your lower tree has a removable stem, like on 39 mm trees, then you should press the stem out. Leave the snap ring on and press it the long way, otherwise the snap ring groove will gouge the aluminum in the stem's bore. Find a socket with a 1" diameter and use that to locate the slotted piece, clamp it in place and mark, drill and tap 1 screw location. It may be more accurate to mark the location with the slotted piece clamped in place upside down. It's also suggested that you use a transfer punch to locate the holes, just tapping lightly to leave a mark, which you then deepen with a center punch. After that, fasten it down with the screw and mark, drill and tap the other three holes.

Be careful tapping. Use lots of tapping fluid. Turn the tap 1/2 a turn or less, then back it up to break the chip. Clean the chips out a couple times during the process. You are strong enough to easily break a 10-32 tap (I think that's the size) and you don't want the headache that happens if you do.

If you have a non-removable stem, you can use the stem to locate the slotted piece while you clamp is and mark one hole. They make drill bits in extended lengths long enough to drill the lower tree with the stem in. It's best if you do this in a drill press to make sure the holes are straight. The also make tap extensions. This stuff is available through McMaster-Carr and others. I have more tools than money so I used a piece of rod, drilled for a tight, straight fit in the lathe, to extend both my tap and drill bit. I JB welded the bit (after roughing it up a bit) and the tap into the rod. Use the better holding 24 hour stuff, and buy some fresh.

Piece of cake.

[TriNortchopz]

Like MOTher said,"Piece of cake. " Great direct experience info that you don't get from online suppliers.
Now here is what a distributor says;

Here is a pdf from Pro1:
#103423 INTERNAL FORK STOP KIT
STEP 1: See FIG. 1:
If necessary, drill and tap 4 holes in the Lower Triple Tree (10-32 x 1/2”deep) using the
Fork Stop Ring (#4) as a template.
Note:
All Pro-One Triple Trees, and several other brands, are supplied
with these holes pre-drilled.
STEP 2: See FIG. 2:
Install the Fork Stop Ring (#4) to the
Lower Triple Tree as shown using the 4 supplied screws
(#5).
Note:
Use Red Loctite or equivalent on the screws.
Warning: There is a short and long travel slot in the
Fork Stop Ring. The short travel slot is used for the
majority of applications. Use extreme caution if using the
long travel slot as the triple trees could hit the gas tank.
STEP 3: See FIG. 3:
Install your neck stem, then drop the Bearing Dust
Cover (#3) over your neck stem on the upper Triple tree as shown.
STEP 4: See FIG. 4:
Drive in the Top and Bottom Fork Neck Cups (#1 & #2).
Then drive in the fork neck bearing races into the Top and Bottom Fork Neck
Cups.
Note:
Your frame must have a pilot hole drilled (or notch) at the
6 o’clock position to accept the pin in the Bottom Fork Neck Cup (#2).
All Pro-One frames and several other brands have this hole pre-drilled.
Need to go here to see photos:

https://www.pro-one.com/v/vspfiles/assets/images/103423ForkStop.pdf

[MOTher]

Part 2

On the fork cup that presses into the frame, with the tab in the back, there is a small hole. They expect you to drill through that hole into the frame parallel with the stem, and make it a tight or light press fir for the provided pin. Only after that do you install the bearing race. I've always thought that the provided pin is pretty lightweight, and if you forget once in a while and let the forks slam against the stop you'll shear it. Then the cup could turn in the frame.

I believe a better way is to drill and tap into the frame perpendicular to the stem and put a grade 8 button head, maybe 5/16" or 3/8" in there. Much stronger Besides, I bought my kit from someone who had already pressed the bearing race into the cup, so I'd have to get pretty lucky locating the pin hole.

Here's a pic of when I did this. In this instance it was for a pair of raked cups, but it's the same principle and the only pic I have that illustrates my point. The bolt will come through into the neck stem bore a little, but you can clean that up with a die grinder or a dremmel or even a file. I shouldn't have to mention it, but use Loctite.

[MOTher]

OK, one more thing after having read the PDF from Pro One. I never drive fork cups into the frame with a hammer and drift. I use a piece of 1/2" allthread, some washers, nuts, and an old fork cup that was filed in the lathe to be a slip fit into the frame. For the bottom cup put the slip fit cup in the top position use heavy washers that center the allthread in both cups and tighten the nuts. It gives you a nice even pull so it's easy to get the tab for the fork stops where you want it. (use grease too.) Then for the top cup, all you need is the allthread the washers and nuts. If you really feel the need, once the cups are all the way in, you can give them a smack with a hammer and drift to make sure they're bottomed. For the races you need a washer just smaller than the bore the races fit into, but big enough to catch the top edge of the race. I had to make one.