
Today I went to the dentist this morning, but
my appointment turned out to be for tomorrow—total strike out!
I trudged back to the shop, and the customer I’d scheduled was waiting outside.
Phew—we made it! Plus I’d left my phone at the shop.
So everything worked out? I guess?
This mystery ailment—the fuses were blowing recently but now they’re not? That sort of thing, more or less.

We’re upgrading the rear disc to a fancy Works Exponent (220φ).
Change the outer diameter and you have to change the support too. Hmm, tricky.

Each one is so cool, I have to say.
These days the parts lineup is so rich you can customize almost everything with bolt-ons.
It’s really become convenient. (‘ω’)ノ

This time I decided to use a different support (on my own initiative).
Normally I’d use the 69720-27A01 up through the GSX-R1100J, but it has bushings and oil seals inside—a floating structure.
We’re using it rigid, and since we’re mounting the wheel speed sensor on the caliper support, we want something thick-walled, affordable, and with excellent bare metal finish.
So we’re using the 69721-35F00 from around the GSX-R1000K1.
The shaft diameter is 28φ and the overall width is thin, so I’ll machine a convex spacer, press it in, and finish it.


Pop it in the oven and press it in smoothly. The aluminum expansion is incredible—I’m genuinely impressed.
The offset dimensions are almost identical (I measured a tiny difference, but close enough), so you gotta love Suzuki—I was quietly moved.
I’m using this one from now on.

Next, we’re installing aluminum pistons (69100-40811 from around the GSX-R1000K1-2) into the GS1200SS rear caliper (Nissin).
I wonder if these are going to be discontinued too. Everyone, the GSX-R1000 is already 20 years old.
( ;∀;) No wonder we’re all getting older.


Parts from this era have internal treatment, so corrosion is almost nonexistent—a real lifesaver.


Still, I wash everything thoroughly and dry it completely in the oven before assembling the parts.


Always inspect the seals—it gives you peace of mind. It’s a good idea to replace the bleeder nipples too.

Caliper OH might be getting easier—or maybe it’s just the magic of Metal Rubber MR20, that wonder lubricant that makes you feel like you’ve improved.
The piston really does slide in smooth as silk.

Caliper OH assembly complete.

I was going to center-adjust on the support side, but it turned out fine.
Maybe the world isn’t all bad things after all.
Next time I’ll install the wheel speed sensor. (I’ll skip welding to save time!)
