I dunno, it just seems like the holes are going against the direction of travel to me, though I can't imagine EBC fitting the rotors the wrong way around.

Very impressed by the quality of these discs though.

There are left- and right-side hole patterns in EBC discs. That's a left-side pattern. According to others who have installed discs like that, it makes no difference in performance, and has the bonus of putting your personal stamp on your moto.

They're supposed to aid water dispersal. As the brakes go on, rather than wait for all the water to be compressed and flung out at the rim which delays braking, the holes provide a 'temporary storage' area. That's the theory anyway; doesn't matter a blind cuss what the pattern looks like. In practice they have a habit of getting clogged up with brake dust

It reminds me of a scene in Life of Brian. The mob are chasing Brian and as he runs away, he loses a sandal. Someone in the crowd sees the errant thong flop, stops and grabs it, holding it aloft and crying out, "It's a sign, we must remove a shoe," and she takes off her left sandal. Many agree and take off their left sandal. While another person in the crowd, removes the right sandal. Upon seeing their difference they go at it, arguing over whether it's meant to be taken as left or right, up or down, east or west, north or south. A rumble ensues, since time immemorial.

My argument, by chance only, suggests it's the wrong way round. Here's Big Block sporting an EBC-brand rear disc. The bloke fitting your disc to its carrier was perhaps dreaming of a Friday on a Monday or Saturday night on a Friday arvo. 

I too reckon it'll make little difference to the water being flung away, but those bloody little chunks of brake dust might have a bit of a disagreement with it, and so will the rider, who has to attempt to forget about this tiny little slice of mechanical minutae before each ride.

TWB; Always look at the bright side of life  

Never had a rear disk with holes, guess I don't need the holes.
Did a testride on a '83 K100, after 20km I noticed the red triangle in the dash.
Holy bugger of god, what did I miss before start riding?
Ow dear, forgot to hit the rearbrake.... 1 tap and the light goes to sleep

Holes go the other way on my new EBC disc (same as 2 wheels). The disc centre has tapered holes for the 2 retaining screws so it should only go on one way round.
I'd complain to EBC if they've assembled it wrongly.

Update: The plot thickens ... I've just looked at the pictures on Motorworks site, and the holes on non-ABS go the "right" way, the ABS one goes the "wrong" way.

non-ABS
https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=BRA00611

ABS
https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=BRA00661

Good spot stanthomas 

I've done about 50 miles and have to say, they're great discs (well disc - I only changed the rear). I just can't stop seeing it as out of flow, as TWB suggested  

Well seeing as we're still in lockdown (are we still in lockdown in the UK, does anyone know?) this merits further thought (i.e the application of an underemployed brain)
The centripetal forces on the water/brake dust/whatever, will drive the stuff radially across the disc, so my completely unscientific postulation is that the application of the brake, and the consequent presence of the pad tight onto the disc will sweep the water/brake dust/whatever into Hole A, being the closest hole to the centre - or Mercury, if you want to use a planetary analogy. As the disc continues to rotate, Hole A (Mercury, remember) will become exposed as it passes past the brake pad, and its contents: the water etc. will emerge and pass radially, further outward. The arrival of the brake pad on the next rotation will sweep the water etc. into Hole B (Venus) and so on. The net effect being that the holes assist in the migration of water etc to the perimeter of the disc where they will be expelled from the disc (solar system) completely. like the Voyager space probe, if you like. This principle, if it exists at all, works best if the holes are arranged to flare outwards with the rotation of the disc.

However, by this time the bike will be a pale blue dot, one third of a pixel in size. All the journeys ever travelled, all the side panels that ever fell off...all the fuel level lights that flickered pointlessly.....

Aaaaaargh

Try that in the southern hemisphere, when flushing a dunny, or watching a whirlpool spin, and observe the opposite rotation from 'up north'.
Reckon it maybe could might be an equatorial thing? Bonzo's rear disc got put into a box meant for Stralya or zud Africa.

Two Wheels Better wrote:Reckon it maybe could might be an equatorial thing?

I think you've nailed it.

Yes of course, the Coriolis effect.
- Invented in 1841 by celebrated Irish scientist Cormac O'Coriolis, who discovered that inducing a whirlpool effect in an inverted bottle of Guinness improved the efficiency with which it could be emptied into a glass!
Cheers!


Will lockdown end soon, please?

The disc I fitted appears to work in both Australia and here, the hole pattern is reversible.

I have not yet tried driving past the Guinness factory (less than 10km away) in case I get drawn into a vortex.

Just get a solid disc.

chris846 wrote:Yes of course, the Coriolis effect.
- Invented in 1841 by celebrated Irish scientist Cormac O'Coriolis, who discovered that inducing a whirlpool effect in an inverted bottle of Guinness improved the efficiency with which it could be emptied into a glass!
Cheers!


Will lockdown end soon, please?

Are you absolutely sure that's not Spike Milligan?

Feckin hell, I'm not even sure I'm not Spike Milligan!

chris846 wrote:Feckin hell, I'm not even sure I'm not Spike Milligan!

Any sign of walking backwards?? Then YOU ARE

Looks like EBC agree it's not right and you'll be able to exchange the disc for one with the correct rotation.

This is the reply from Gareth Preston, EBC Motorcycle Technical Advisor:

As my previous email advises, I believe Bonzo has the incorrect directional disc. This is a production error and I have checked the remaining stock and no other discs we have here in the factory are affected.


I shall sign up to the forum and place a comment on the forum thread asking anyone affected to get in contact.

Ringfad wrote:The disc I fitted appears to work in both Australia and here, the hole pattern is reversible.

I have not yet tried driving past the Guinness factory (less than 10km away) in case I get drawn into a vortex.

No Ringfad???? But I see an Aussie in there and he doesn't look inverted.

stanthomas wrote:Looks like EBC agree it's not right and you'll be able to exchange the disc for one with the correct rotation.

This is the reply from Gareth Preston, EBC Motorcycle Technical Advisor:

As my previous email advises, I believe Bonzo has the incorrect directional disc. This is a production error and I have checked the remaining stock and no other discs we have here in the factory are affected.


I shall sign up to the forum and place a comment on the forum thread asking anyone affected to get in contact.

Thanks for that Stan. I'm definately struggling to 'unsee' this 

Spike Milligan made sure that his words were put on his grave stone. "I told you I was sick."

Normal service has been resumed.

With many thanks to stanthomas who reached out to EBC behind the scenes, Gareth Preston contacted me and confirmed that there was no safety issue with running the discs out of swing, however they looked 'wrong' and so we arranged a swap for a new 'right' disc which arrived this afternoon. Pretty good customer service there from EBC I'd say.

So, all is well and massive thanks again to Stan & Gareth 


EDIT* Blimey my bike is minging dirty. Current hose pipe ban is my excuse 

Ain't it sweet when a corporation actually care what their customers think of a product, even if it's just wrong to look at?! Kudos to StanThomas, and to EBC. I continue to use EBC brake pads, brake discs and clutch discs/plates on my own bikes and have successfully used their product on many customers' bikes over the years.

Two Wheels Better wrote:Ain't it sweet when a corporation actually care what their customers think of a product, even if it's just wrong to look at?! Kudos to StanThomas, and to EBC. I continue to use EBC brake pads, brake discs and clutch discs/plates on my own bikes and have successfully used their product on many customers' bikes over the years.

Well said TWB, couldn't agree more.

I'll be replacing the fronts at a later date and EBC's will be a no brainer.

(Gareth mentioned he is awaiting acceptance to the forum or he would have posted earlier. One of the good guys )

Bonzo wrote:EDIT* Blimey my bike is minging dirty. Current hose pipe ban is my excuse 

You've never seen one of mine then...