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  Wavy discs

I have liked Wavy discs ever since I had one fitted to my WR400. I can't say it made the bike stop any better, but it did have that cosmetic look and certainly enhanced a supermoto.

When it comes to sports bikes, Kawasaki started to fit the 'Petal' disc to the ZX10R back in 2004 but it wasn't what I would have called Wavy. Anyway, I've been looking for a set of wavy front discs for my Blade for some time now on E-Bay and have always been outbid, mainly because I refuse to pay the sort of money the likes of Galfer and Braking etc. ask for their discs, it just doesn't seem value for money to me, and seeing as E-bay stuff was all 2nd hand you'd expect to pay a lot less. But oh no, people were still prepared to pay well over 200 quid for 'used' ones.

Therefore I had admitted defeat and resigned myself to the fact that I wouldn't buy any. Until, that is, I saw another ad on E-Bay Motors, this time for a set of 2 front and one rear wavy discs for 99 quid??!! As always there is a catch, these discs come from China. But the 99 quid for 3 seemed value for money nonetheless. I perused their site and had a good old look at the specs and I couldn't see where I could go wrong, except that perhaps one day I may not stop; but the structure, materials, machining etc. that goes into these looked good enough for 99 of anyone's pounds.

Whilst bearing in mind that my current Golf Clubs are Taylormades and they come from China, well the factory next to the Taylormade Factory, obviously being Jekylls, I thought why not, those clubs are excellent and a fraction of the price. So, admittedly, with a certain amount of trepidation I took the plunge and bought some. They turned up in the next 5-7 working days (as advertised), and were even delivered through TNT. I opened them and quite expected the holes not to line up or something obvious that you would notice with a copy of an original, but what are these copies of exactly? They are not advertised as copies of Galfer or Braking items, they are their own, but a less expensive option made by a company called Villamotor.

I aligned them to the stock discs of mine that were off the bike anyway and I couldn't fault them, all the holes lined up, the offset of the carrier was perfect, the leading edges of the discs were machine hardened, (I don't know the technical engineering name for it), in black. Both the front discs weighed exactly the same as each other and exactly 162 grammes (each) lighter than the originals, and that's after 3 years of wear on the OEs.

Needless to say they are now on and have been bedded in with new pads. At first they seemed completely rubbish as all new disc and brake combinations do, but after putting 30 miles on them they feel as good as the originals. But I think they look better and they should equate to a gyroscopic saving of 324 grammes, so less unsprung weight too. Multiply that lot by 4 to allow for some mathematical mysteries and I have lost approximately 1.2 kilos of unsprung rolling mass and should have improved the steering reaction in the deal too, i.e. quickened it.

I haven't tried the rear one yet, that is on my spare rear wheel, but I guess this isn't quite as important as the front ones, they will be taking all the stress and have quite a tough job ahead of them.

If I find these things start to warp when used in anger I will of course ensure there is a message on this site to ensure people are aware and advise you not to do the same as me.

You have to realise that we do not do this site as a guide of what one should do, we do it purely for fun and to tell anyone that is interested of our exploits and what we think, and what we try etc. I could be completely insane for doing what I have done with these brake discs, but you will find out. If an update is required, hopefully it will be written by me, if it's written by the Ed, then you know what's happened to me and my wavy discs from China ...

Until the next time, insh'allah.

Tet

  A bit of friction

4-pots, 6-pots? Radial? AP, Brembo, Billet, Alcon, PFM? Nissin, Tokico? Braided hoses? Race pads? What makes a good brake setup?

Basically, it's all down to the coefficient of friction between the pads and the disc, the rest is just the medium used to squash the two together.

6-pot calipers were supposed to be the ultimate solution for sport bikes, but then Yamaha produced stunning brakes on the R1 with 4-pots and Honda came up with possibly the best road bike brakes ever with the 4-pot Nissins on the SP1. Compare this with the relatively weedy 6-pot Tokicos on the GSXR.

AP and PFM calipers and ultra-thin discs certainly look good, and may save a tadge of unsprung weight, but there's no real reason why they should be better than a standard setup. The hardware determines the working brake surface area and the pressure applied, but it's friction that stops the bike, and the level of friction depends on the pad and disc materials and their interraction at different temperatures.

Racers can produce the best setup for a limited temperature range, but road bikes have to have effective braking when cold and wet as well as red hot, and the pads have to last for a reasonable mileage. So ultimate stopping power will always be a bit compromised.

If you want to look the part, both AP and PFM do conversion kits which give you the thin lighter weight discs, 6 pot calipers, and braided hoses, but they're not cheap ... between £1000 and £1200, and that doesn't include a posh lever assembly - and you've gotta have an AP lever to really cut it!

If you just need to replace your shagged standard discs then EBC, Brembo and PFM offer straight swaps, prices starting at a couple of hundred quid. These are marketed as high carbon steel, which is supposed to give you higher friction, but not all are stainless, so expect rusty discs after a wet night if your bike lives outside.

'Course, radial brakes are all the rage at the moment. The theory is that a radial two point mount, as opposed to the bendy fork arm extension, means no flex so better feel. And they look trick, which helps. They don't help poor brakes, though. The best non-radial road bike brakes still outperform many of the new radial designs.

Best current production brakes? Gotta be the Fireblade and SP2. Loads of bite and feel without being grabby. R1/R6 come next, equally strong brakes but can grab initially if you give them too much of a handful. Suzuki are as Suzuki always are, a bit feeble - plenty of stopping power eventually but no bite.

  Third party pads

Winter salt has rusted the linings a bit and the swept area of the SBS pads is clearly visible as the darker area in the centre of the disc.

I was prompted to write this drivel on account of my recent experience with brakes, more particularly the linings therein affixed.

Being the proud owner of a GSXR750WX, I reckon the brakes are pretty good as standard, giving loads of initial bite and good progressive stopping. Anyway, the day dawned when they were looking a bit thin and a trip to the 'Ring was due that weekend. I hot-footed to the local Suzuki dealer for a new set of pads.

"Don't stock Suzuki's pads, we do SBS which are just as good" quoth said dealer. Oooer. Now I've always been minded that the OE pads are best, as presumably the major manufacturers do yurgons of testing the ensure an ideal match between pad and disc, allowing for half reasonable wear rates. However, time was pressing so I purchased the SBS pads in a nice soft racer mixture. However, getting home and comparing them with the originals and it was obvious that the lining material area was significantly smaller on the SBS. OK as far as it goes, but the pad will only wipe a limited part of the disc, which will wear a slight groove. Then, if you go back to larger pads the disc will develop a horrible uneven surface as the new pads firstly rub only on the unworn part and then slowly deform and start to blend the area between ther wear levels, producing a slightly dished shape and uneven ridges. Then the disc is scrap. This happened to the OWO1 and I never twigged why ....


Reduced lining height means only centre of brake disc is used - compare with correct size lining on right

Anyway, time was short so I fitted the SBS pads and went to the 'Ring. Braking was good, especially when they were hot, so well pleased with the performance. Getting home, I checked around for replacements before the discs became worn, and found some Nissin pads which had lining material the right size. Bingo! But they were crap, which is odd as Nissins were always considered top pads. Not to worry, to the rescue came KRJ with some groovy race spec Dunlopads, which he uses for racing and considers to be jolly good. But blow me, they were the same as the SBS, with undersized linings.

So, biting the bullet, I ordered a set of genuine Suzuki pads .... at £80!! Fitted 'em and immedately I've got my full-on brakes back, loads of initial bite and progressive stopping from high speeds. I was lucky that the SBSs hadn't buggered the discs.

So what I want to know is, why do some third party manufacturers use the wrong size linings? Reason? My guess is that they are used on a range of other pads and it's cheaper to just use what you've got rather than make new ones. As in all things, you get what you pay for.

So, if you've been using third-party pads and you decide on a change, check that the new pads have the same size (or smaller) lining otherwise you'll have to replace your discs in the not too distant future.