Yesterday, I am back to fine tune the front axle again.
First I took out the entire front wheel assembly out:
This is the left side where the speedometer drive supposed to be, but not able to fit it since the 5mm brake rotor spacer cause the brake rotor bolts to hit/rub the speedometer drive:
Took out the brake rotor and this is the 5mm black spacer still there:
Took out the 5mm black spacer out:
I bought this assortment of brake rotor spacer of 2mm, 2.5mm, and 3mm from UK to test fit:
I decided to start with the thinnest 2mm hoping it will give the most clearance for the brake disk bolts to clear the speedometer drive while still enough space out to fit the brake pads (center as much as possible for the brake caliper):
Turn out, even with 2mm, the speedometer drive barely clear (but just enough to clear) the low profile ProTi Titanium brake rotor bolts, which means, I need to use the 2mm spacer no matter what:
This is the right side (non speedometer side) now with 2mm spacer, the good thing is this 2mm spacer also allow the Brembo T-Drive Brake Disk Rotor to still hubcentric to the hubcentric lips of the Marchesini wheel:
Next, I need to test fit the right front axle spacer, and I bought an assortment of size of 3.2mm, 3.4mm, and 4.75mm (this last size is 316 Stainless Steel, while the first 2 thinner is aluminum):
First test, with 3.2mm aluminum axle spacer, and the result, the axle nut on the left side of the axle still have space (gap), so I need thicker axle:
Second test, with 3.4mm aluminum axle spacer, and the result, the axle nut on the left side of the axle still have space (gap), so I need an even thicker axle:
Third test, with 4.75mm 316 Stainless Steel axle spacer, and the result, the axle nut on the left side of the axle now FLUSH, so this is the right spacer thickness:
Once I found the right axle spacer thickness, I now need to review how the brake pad is located against the surface of the disk brake. It doesn't have to be trully center, but it need to have clearance so it won't drag:
Left Caliper could use a bit thicker brake rotor spacer, but that mean it will not clear the speedometer drive, so I have to be happy with this not so centered position.. well, I am thinking of adding 0.5mm shims between the speedometer drive and the Ohlins Motocorse fork leg (need to do more research):
The right side caliper is almost perfect:
This is how the speedometer drive, now successfully installed and still clear the brake rotor bolts. I had done research and so far no one had been able to make the 998 original speedometer drive work with a radial caliper conversion unless they use the 998R 15mm offset brake rotor (which I don't like the looks).
Because they usually need the 5mm spacer which make the speedometer drive not clearing the brake rotor bolts.
This is the only combination and it require specific Motocorse for Panigale V4 fork leg in 108mm brake caliper bolt spacing (not the original Panigale 100mm caliper bolt spacing). This make it has a very unique offset that a 2mm brake rotor spacer can be use.
(In fact the 5mm spacer does not really work in this setup). I am lucky that I was not tempted to purchase the 15mm brake rotor offset of the 998R, because I really want to use Brembo T-Drive rotor. I am lucky that I decided to do it the hard way with spacer and tune the spacing.
Because normally the 998R with 15mm offset rotor is the simplest solution that still allow the speedometer drive to be used for a radial caliper conversion (using the 100mm caliper spacing stock Ohlins fork bottom).
Since now I have found the right brake rotor spacer thickness of 2mm, I decided to custom order a 7075-T6 aluminum brake rotor spacer that have a nice cutout following the shape of the Marchesini wheel mating surface.
The 2mm aluminum spacer I bought from UK above is too crude with cheap aluminum material, so I don't like it. Plus the inner diameter at 65mm is too loose, it need to be around 64.15mm ID.
This custom 7075-T6 machined aluminum spacer should arrive in a month or so.
I also ordered several combination of Titanium Axle Spacer so I can choose which I like the most (should arrive in a week or 2 week).
I still need to do some research on the 0.3mm to 0.5mm shim to make the left side brake pads more centered with the brake rotor... will do it now...