“Flavor Change with Do-Re-Mi? ZEPHYR750 Becomes Z2” ZEPHYR750RS Front Fork OH

The air conditioning in the shop is working well, but the temperature difference is getting to me in a weird way.
If it’s hot, it’s hot—maybe that actually makes the work easier? I’m not sure.
Too hot is definitely no good though…

So let’s disassemble this beautiful ZEPHYR750 RS front fork. (*´ω｀*)

Let’s quickly disassemble the front.

The ZEPHYR750 is apparently using an SR 400 front fender, but…
The fender is narrow and fixed with bolts, so it looks quite odd.
It doesn’t look great, so we’ll adjust it at the end.

After all, a proper upright fork! Non-cartridge is the way to go.

The fork oil was surprisingly clean.

Before assembly, we’ll do various preparations.

The cylinder’s threaded section has thread locker residue stuck on it.
By cleaning it thoroughly with a tap and getting it to the point where bolts slide in smoothly by hand, you can’t go wrong.
ZEPHYR750RS Cylinder M14-P1.00

The stroking section of the inner tube wears down and loses its smooth feel.
It often becomes dark and shadowy or develops vertical scratches.

If you polish the inner tube carefully on a lathe and with scotch pads to avoid scratching it,
the scratches become smooth and the oil seal is less likely to tear.

The inner tube showed no bending.

Hoping to add an initial adjuster to the ZEPHYR750RS

Here it is—unfortunately M 38-P1.00.
In other words, it’s the same size as the ZEPHYR400/550.
The customer wanted an OEM-looking initial adjuster, but I suspect it doesn’t exist.

Hyperprо Preload Adjuster Fitment Info M38-P1.00 22635301 *Previous Post

Everything is assembled, so let’s vacuum and bleed the air.

Since it’s a non-cartridge upright fork, we could bleed it by stroking, but
we’re doing a thorough vacuum bleed just to be safe.

Next is assembly and we’re done!—or so we thought, but

The original bolts were rusty, so we replaced them.
I prefer iron bolts—they’re reliable.

The axle shaft showed no bending.
The ZEPHYR750 has a 17mm axle shaft.

It’s frustrating—it looks like it could be adapted but the shape doesn’t quite work.

Make sure the axle shaft inserts smoothly when free.

Let’s fix the SR 400 fender mounting.
I really want the front fork to move smoothly.
If the front fender has just a little resistance when initially fitted, it won’t put strain on the fork.

This time, we made four 8.00mm spacers, which allows the fender to be mounted without stress.
Since it’s already slightly deformed, we need to adjust case by case.
Of course, the bolts need to be longer by the thickness of the spacers.

Just when we thought we were done…

When we installed the wheel,
the ribs on the front fender contacted the tire, so we smoothly ground them away.
Bias tires require special attention, asthey grow significantly in diameter at high speeds.
When adapting a front fender on a motorcycle with bias tires, you should be very careful.

Surprisingly Popular? ZEPHYR750 SR400 FenderIt’s quite a common adaptation…
Now we just need a test ride to finish.