Hello everyone.
Today is part 3 of maintaining the antlion ride height adjustment kit for the Honda XR series.
Last time (part 2, in Japanese), I showed how I got hold of the rod-end (spherical) bearings.
This time I show how I pumped grease into the grease nipple on the rod end.
Grease nipples are usually greased with a grease gun.
Instead of a full-size grease gun, I used the mini grease gun shown above.
I bought the nozzles thinking the standard nozzle (far right in the photo) might work.
Incidentally, I bought this grease gun for greasing bearings.
I also looked for a nozzle that would fit the nipple.
First, remove the tip of the mini grease gun.
It comes off with a 12 mm socket.
Here's the mini grease gun with the tip removed. On the right is the tip, on the left the gun body. There was a spring in the body.
Now let's take another look at the standard nozzle and the grease nipple.
From the shape, it looks as if it might work.
First I try greasing with the standard nozzle.
Pressing the nozzle onto the nipple quite hard while pumping...
As in the photo above, I managed to get grease in.
Dark grease was squeezing out around the ball of the rod end, so I think the red grease I pumped in had spread through the inside.
...However, it needs a lot of pressure to get the grease in.
And after taking the nozzle off, residual pressure pushes quite a lot of grease out of the nozzle tip, which is wasted.
(I put the excess grease back into the tin afterwards.)
Next I try the narrow-access straight nozzle.
As the photo above shows, it can't be used as it is.
So I decided to cut off the tip and fit this nozzle made for grease nipples.
The dedicated nozzle I used is THK's N-type nozzle (part number MG70-N), an optional nozzle for THK's grease gun unit that fits rod ends such as the POS series.
I clamp it in a vice and cut it with a hacksaw.
The cut is done.
I plan to enlarge this hole and fit the dedicated nozzle I'm holding.
The cut scratched the surface, so I tidy it up with a file.
The file is a Tsubosan. It doesn't clog easily and it cuts well.
The thread on the dedicated nozzle measures 4.8 mm in diameter. M5, I guess.
The thread pitch is 0.5.
I enlarge the hole so that the dedicated nozzle will go in.
And here's my mistake.
I used a 4.5 mm drill bit. That is the usual tap drill size for M5 x P0.5, so I think the hole size was fine. I believe the real problem was that the metal I drilled was very thin, so only a few threads could be cut (or perhaps the nozzle went in slightly crooked).
With the hole drilled, I offer up the nozzle for now.
This is an M5 x P0.5 tap.
I didn't have one, so I bought a fairly cheap one.
Now I tap the hole.
The tap has cut a thread, so I wrap sealing tape around the dedicated nozzle and screw it in.
It's a little crooked, but I managed to screw it in.
I fit it to the mini grease gun.
Obviously, since this nozzle is made for this grease nipple, it sits nicely.
It still takes a little force to press the nozzle onto the nipple, but it seals against the nipple with much less force than the standard nozzle.
Grease is in.
Here too you can see grease seeping out around the ball.
There also seems to be less residual pressure than with the standard nozzle, so less grease squeezed out.
That's how I greased the rod ends.
It worked, but it took quite a bit of effort.
Here's a quick table comparing the standard nozzle and the dedicated nozzle.
| Standard nozzle | Modified narrow-access nozzle with dedicated nozzle |
|---|---|
| Standard nozzle (432 yen) Total: 432 yen | Narrow-access nozzle (728 yen) Dedicated nozzle (1098 yen) Total: 1826 yen |
| You have to press the nozzle firmly onto the nipple while pumping. After greasing, residual pressure pushes out quite a lot of grease. | Only light pressure on the nozzle against the nipple is needed while pumping. Less grease comes out from residual pressure after greasing than with the standard nozzle. The parts need modifying to use the dedicated nozzle. *With the matching grease gun, the dedicated nozzle fits without modification, but that grease gun costs 7,000 to 8,000 yen. |
Besides this, I think you could also remove the parts containing the rod ends from the bike and grease them off the bike.
Greasing the rear linkage affects the ride directly, I think, so I hope this post helps someone.
Added 31 December 2025
I found a way to protect the rod ends, so here it is (in Japanese).