Heard a rattle from the front end the other day while manoeuvring the bike over some bumps as I pushed it into my garage. After grabbing & shaking anything I could get my hands on I located the source. I found the left side disc rotor had a massive amount of wear on the bobins with way to much side and up and down movement. These Grimeca rotors that several of us have fitted are Aprilia RSV parts and have only been on the bike for about 5000 km. I immediately refitted the standard GRiSO parts as the level of wear was excessive an to my mind potentially dangerous. Strangely the right side was ok only showing minimal wear and the brake performance was fine and there is no logical reason why it should have this much wear. This may be just a one off defective part but I would suggest those that have fitted them, should check them to see if yours are ok. I won't be fitting them again as the cost of replacing the defective item is not justified as I believe the performance gain from my perspective is marginal. Excessive wear on carrier . [You must be registered and logged in to see this image.] Side deflection of rotor in relation to carrier in both directions. [You must be registered and logged in to see this image.]
odder GRiSO Capo
Posts : 160 Join date : 2014-10-14
Subject: Re: ### WARNING ### Grimeca Disc Rotors Sat Jul 07, 2018 12:18 am
I’ve seen some folks replace the bobbins with aerospace bolts converting to full floaters. Work well but make a racket.
Have yet to do this mod to my GRiSO.
beetle GRiSO Capo
Posts : 10198 Join date : 2013-09-30
Subject: Re: ### WARNING ### Grimeca Disc Rotors Sat Jul 07, 2018 12:51 am
. [You must be registered and logged in to see this image.] . In GRiSO we trust! .
Guest Guest
Subject: Re: ### WARNING ### Grimeca Disc Rotors Sat Jul 07, 2018 1:54 am
If only one disc has the problem, then I would suggest that it may be faulty.
I've got BrakeTech Axis Iron rotors on Bella, rattled from the day I bought them. They are full floaters but have a different attachment design that doesn't impart any of the braking loads thru the bobbins. Slightly heavier than Grimeca, and much costlier, about USD$700 a pair. AUD$1000 landed here 5 years ago.
Yeah, it is logical to assume that I had a dud one. Unfortunately unless I can buy another one, I have spare unit which is of no use to me and based on the obvious quality questions and cost, I don't think I will bother.
The purpose of the post was to warn others, as I had not noticed the wear prior to hearing the rattle as the brakes were performing correctly.
I recently purchased a pair of front rotors, but I actually bought 2xright side ones. The rotors have an arrow showing direction of travel.
I asked the bike shop to install them as they were putting new tyres on. They picked up that the discs were both right side and refused to install them.
Maybe your left rotor is actually a right side.
It could explain why they have different part numbers, when they look identical.
I haven't fitted mine at all and am trying to source a specific left hand side rotor, but haven't had any luck. Grimeca haven't replied to my emails, neither has the place I purchased the rotors from.
Anyone need a couple of right side Front rotors, going cheap!!
No, yours look the same because you do have two the same. Mrgpz, look a bit better, the hole pattern in the disks is the other way around. So if mounted like they should, it looks good. Grimeca sells these only to Piaggio. They won't answer you. And they were declared bankrupt after they made yours.
What partnumber do yours have? I might be interested
But anyway, This week a friend with a 2009 stelvio, had same problem with the floaters, but with OEM brembo disks. After 80.000km. massive play.
I know a lot of people using these disks, without this problem, also racing with them.
Pad buildup Ron? This was a problem with the Sport/Breva/Norge disks early on, and resulted in many a disk being replaced under warranty due to being "warped". Turns out the bobbins were way too tight for a floating disk. In fact they didn't float at all. Cleaning the bobbins cured the problem.
Pad buildup Ron? This was a problem with the Sport/Breva/Norge disks early on, and resulted in many a disk being replaced under warranty due to being "warped". Turns out the bobbins were way too tight for a floating disk. In fact they didn't float at all. Cleaning the bobbins cured the problem.
Could be Tony. I seem to have developed a more cautious approach to my bike maintenance for some reason I’ll check it out soonish. One is struggling to wipe one’s bottom as yet
Subject: ### WARNING ### Grimeca Disc Rotors 
Fri Jul 06, 2018 11:51 pm
I’ll check it out soonish. One is struggling to wipe one’s bottom as yet 