Fitting RC8 R forks to the 390….. Works Great !!

[psych0hans]

Sorry for the major delay, but as promised, my notes on the RC8/RC390 fork conversion. I'm no machinist or engineer so excuse my amateur attempt at drawing the measurements…. This is what I have…..
Keep in mind, I'm also using a single (320mm) front rotor from a Yamaha FZR1000 mounted backwards !

Better late than never! Thank you for the help, my spacers were made very differently, so now I know where I went wrong. The spacer with the collar, I'm assuming the collar goes on the inside of the fork? Also, you reused the stock spacers on the wheels, I'm assuming?

 

[Old3]

No room for the abs ring.... Hmmmmmm. I think I will stick with my hybrid set up then as I have the brakes pretty much awesome/ excellent and my damping and spring rate are spot on too.

Not willing to lose the speedo regardless.

Good info guys, thanks for keeping it updated.

 

[jokerio]

Better late than never! Thank you for the help, my spacers were made very differently, so now I know where I went wrong. The spacer with the collar, I'm assuming the collar goes on the inside of the fork? Also, you reused the stock spacers on the wheels, I'm assuming?

Yes, the second picture is of the the spacer/adaptor that fits the left fork leg (as sitting on the bike) also known as "drivers-side" (joke)
And yes, stock size wheel spacers are also retained. Also, don't forget and this is very important,… this spacer/adaptor sits in the fork-leg and the stock axle slides thru this so you need to gut a "relief" (length-wise) so it can clamp the axle when the bottom pinch-bolts are tighten

No room for the abs ring.... Hmmmmmm. I think I will stick with my hybrid set up then as I have the brakes pretty much awesome/ excellent and my damping and spring rate are spot on too.

Not willing to lose the speedo regardless.

Good info guys, thanks for keeping it updated.

I removed all my ABS related stuff so I have no speedo, (which I don't care about) But, I believe if you really need (or want) a speedo you could probably use the rear wheel by connecting the front wheel sensor wires (from harness) to the rear wheel pick-up sensor…. It might read slightly off due to the different rolling diameter..

 

[jokerio]

9400111899297886 !

 

[psych0hans]

Hi guys, just sharing some pics of my setup for reference.

1) the spacers I made with the cut that Jokerio mentioned. This cut is very important as this is what will clamp your axle in place. Please note that the cut must line up with the one on the forks for this to work properly.


2) forks mounted



3) end result


4) the reason I couldn't install the ABS ring is because of the clearance between the rotor bolts and this section of the forks.


Good luck and let me know if I can be of further assistance. If I were to do this again, I'd probably try replicating Jokerios spacers and try it that way. I still might in the near future, just to see the difference it makes.