Resuming the aftermarket brake rotor Arashi wawy.
I just wanted to try the rear brake rotor first, not the most demanding in case of emergency braking need.
Wawy design/shape like or dislike is personal opinion, not subject to discussion.
5mm thickness and 4.5mm mini stated instead of Honda 4mm mini.
Nice smooth fine grinded surfaces, definitely flat.
Mounting...
First, removed the stock rear disc... spent time to clean the surface underneath the stock disc due to dirty and weel aluminium oxydes. Sand paper smooth to flat aluminium surface.
The Arashi inner diameter could be tighter to match the wheel recess diameter. Not too much play of centering but not tig ht adjusted like engine mechanical parts.
Each bolt hole on the rotor has a recessment diameter for the bolt head to sit done to the remaining disc thicness.
On the Arashi, the recessment is not as deep as original disc (missing perhaps 0.7-1.0mm,) as a result, the bolts heads sit higher once tighten. No danger, tights the disc well to the wheel.
The little problem of the bolts head higher, when I placed the wheel back to the swing arm, the bolts heads touch a specific area of the caliper.
Each bolt does touch, by analysing the consequences, I decided to "grind" the aluminium area of the caliper by turning the wheel, each bolt head slicing a fraction of metal. The bolt head are so strong, aluminium just been machined well.
Removed maybe 0.8mm, the heads don't touch anymore.
I repeat, I analysed the situation before taking this decision.
Look on this picture of a spare caliper, show you where the heads ripped out a little alu.
0.8mm not far enough to erase the 1/2 circle of aluminium.
View attachment 130287
This was the only little issue during the mount.
3500 kms after, how they are?
Well, rear brake on CBR XX with Dual CBS... not the best system to check how the rear brake slow down the bike by pressing foot pedal... as you know, press strong, even one piston each front caliper linked activation vs 2 pistons activation on rear caliper, front taking advantage on back braking.
I would say, they are doing their job, not more not less than stock rear disc.
My normal usage of the BB (no race track, no open road race, no mountain demanding conditions) it make no difference for my opinion. When I needed stronger braking, I can feel the rear disc is doing his job too but front again is the main stopper.
Finally this is a huge success because this Arashi front and rear set costs the price of one a stock rear disk (if I could afford a full set of stock rotos... I would do it but I can't, you saw my list of parts for the rebuilt...).
If some more experimented driver tried same Arashi discs with EBC 261HH (same disc with different pads would drive to different results I suppose), please comment as I don't want to be the one when write they are good but they are not finally.
Below 3500 kms after. Like new (normal for such low millage). You see the surface trace of aluminium deposite on the bolts heads, superficial deposited.
I will post the same test when comes the need to change the front rotors... More critical than the rear.
View attachment 130288