Disc drilling pattern, thoughts.

[Oddjob]

Found someone who can skim a pair of the 500/550 discs, not that easy to find anyone to do it TBH, most runaway when they hear stainless.

So the person I asked says they have to remove the rotor inner and then they grind the discs flat, they send the inner part off to be resprayed and then reattach using bolts rather than rivets, cost is £75 per disc including the painting, so not cheap but pics of others he's done look like it's a very good job.

He can also drill them, although he doesn't drill the holes but uses a laser cutter to do it, I suppose so long as the pattern is symmetric it's a better job than drilling. He's also offered to design a completely new design, I could for instance have them cut with the word HONDA cut into them, some of the pics he's send me look really unusual, I am however rather taken with an odd design that may look really stunning on the 500, it's not drilled but it has what are essentially large slots cut out of the disc, a bit like modern wavey discs.

Cost to do skimming, repainting and the cutting/drilling depending on your choice is £145 a disc, not so bad if you still only have a single disc fitted but getting a little expensive when you have twin discs like mine. I was going to have the centres powder or ceramic coated after the drilling I was planning before so if you factor in the cost of that and the postage to and from Scotland it's getting closer to the cost. The new place isn't that far from me. The difference is the new design would be totally unique on such an old bike, not a big fan of the standard look, it's fine don't get me wrong, I just like mine to be a little different to everyone elses. The plus side to this is I have 2 spare discs, both have surface damage due to rust and bad storage so I'll use those which are sort of scrap and if the result isn't to my liking I'll just fit the standard discs which were on it before and sell on the altered ones.

Here's what I'm thinking of, I'd just go for the outer part, the internal small blocks might be a bit OTT. I'm also thinking of doing the cuts in the outer part as well, that will really alter the look of a standard disc.



Just for a laugh, here's one he did for another customer. Really impressive job.

[Multiman]

Wow they look spectacular.
Would they not cheese grate your brake pads at an accelerated rate?
I've no idea, just askin.

[McCabe-Thiele (Ted)]

Reminds of when I took my Yamaha to a Honda Dealer for its first Mot - the tester was going to fail it as the rear disc was cracked.

I said to the tester are you sure they are cracked - yes he said in three places! I then said well that's odd as the cracks are symmetrically spaced on either side with an offset between the inside & outside I think they are made that way.  They had a sort of spring steel arrangement in a sandwich not a solid single disc.

He ended up ringing the Yamaha Dealer in Ilkeston before he would issue a certificate.

[Oddjob]

Wow they look spectacular.
Would they not cheese grate your brake pads at an accelerated rate?
I've no idea, just askin.

Modern discs seem to be very similar in design these days, so I'd imagine they'd wear about the same, maybe a little faster, I'm going with SBS ceramic pads this time around and I find them almost dust free and very good grip with prolonged life.

These are my new Galfer wavey discs as fitted to my 1300, not that dissimilar.

[Multiman]

 Fair enough!

[K2-K6]

Running many different hole configuration, albeit on a smaller scale with mtb disc, the geometry is relative though I believe.

You can get away with far more adventurous design with longer pads, 4 pot for example, than single piston type circular pad contact.
They are just more stable when transiting the gap in the design. The good calipers have pad lengths extended quite a way to facilitate this on these design, running a some six pots that you can keep pad stable over most disc type, the pistons are smaller on leading edge to keep wear even though in relation to the largest trailing piston. They are roughly 3 to 4 times longer than width for pads though.

Too much gap with smaller round pads starts to give indication with noise, referenced as "turkey gobble" as it does make that sound especially when squeezing hard and with the pad/disc up to temperature. 

We use Galfer too in a similar arrangement particularly for high mud environments as they tend to wipe the pads with wavy edge and slots etc. Some type are much more cut away which id not use in high heat applications.

For durability, and especially with small round pads, I'd stick to circular holes in pattern of choice. They don't present aggressive edges to the pad in rotation, keep the pad stable with these Honda swing/singoe type caliper, and won't likely change pad wear .

[Oddjob]

Might just be a case of you never know until you try Nigel, I've still got the standard discs to fall back on if they make too much noise or chew the pads up quickly.

[K2-K6]

I like the adventurous patterns etc, it's more with smaller pads it ultimately tries to pull the leading edge of the pad into the disc and I don't like the feel of that aspect in how they operate.

Its a bit like the leading edge of a drum shoe that effectively gives it a servo type mechanical pull, also tries to pull the piston skew in the bore, especially as that comes out further when pad wears.

I've never worried about pad wear in use, that's if the brake does what I want it to do. Or the noise (just that some are obsessed with brake noise and complaining of that ) you'd usually get a sizzling as light contact but that goes away with more pressure, gobble seems to be present when higher pressure meets low supporting structure and gives indication of just how much the pad material is dropping into these gaps.

Be interesting to see wherever you end up, and if in use experience follows any of this.

[Oddjob]

The Brembo calipers I'm fitting to the 1300 next week have 4 tiny pads Nigel, far smaller than the surface area of the 500 pads, you'd think they'd be a bigger problem with such slots.

I'm thinking of altering the way the back pad fits into the carrier as well, was never a big fan of such a small split pin holding in the pad, especially as the holding ridge of the carrier is so small, I was thinking of changing the split pin for a screw, drilling the pad where the split pin goes through and threading a 5mm thread into there, seem to recall there's another Honda which uses that type of arrangement.