Clubsport S discs

[exodus_ste]

So i recently treated the Eddy to a full brake upgrade. Having been using the R32 setup for a while i fancied something a little different so i opted for the AKS Aston Martin Brembo caliper setup with the Clubsport S disc. Threw in some Mintex pads and off i went 

Having done about 500 miles or so now and taking extra care with these expensive discs i seem to have developed what feels like disc warping! Very surprised considering the care i was taking.

Symptons are obviously wobble and vibration felt through the steering wheel and brake pedal. Braking from higher speed with gentle brake pressure is the worst. Heavier pedal doesn't make it much worse, and once below 30/40mph it goes away.

From day one these brakes have 'hummed'. Not immediately but say slowing gently from 75 to a roundabout, after 3/4 seconds of braking the humm/buzz appeared.

So, would that humming be typical of a 4 pot caliper on these semi-two-piece discs? Can discs warp without abuse? Could it be a pad incompatibility?

[bobby_fodge]

Did you clean the hub before fitting the discs and is the centre bore exactly the same between hub and disc?

I chased similar symptoms for ages until I measured the center bore of hub and disc and realised i needed a really tiny spigot ring to stop the vibration.

[pudding]

Are you sure it's the brakes?  Did you change or fit anything else at the same time?  Might be worth getting a cheap dial gauge off Amazon to confirm.

I have the same discs and been using them daily for 9 months. The humming noise went after the pads bedded in and they haven't warped.  It's not unheard of for VAG discs to warp easily though, so you might be able to get replacements if they were fitted correctly.

If yours were also not L&R handed when you bought them, that is also a case for a refund/swap because it means one disc runs a lot hotter than the other.  I think I got a pair of Rights.  I did ask the dealer about it but VW only list one part number for both sides.

[exodus_ste]

Did you clean the hub before fitting the discs and is the centre bore exactly the same between hub and disc?

I chased similar symptoms for ages until I measured the center bore of hub and disc and realised i needed a really tiny spigot ring to stop the vibration.

The front hub and bearing unit are all brand new and i made extra sure there was no debris there. Used an aerosol copper grease on the mating surface to prevent seizing.

Pretty sure the discs located perfectly on the hub, in theory they are the same bore as any of the 312/340/345mm discs. I'll measure eveything accurately when i investigate over the next fortnight.

Are you sure it's the brakes?  Did you change or fit anything else at the same time?  Might be worth getting a cheap dial gauge off Amazon to confirm.

I have the same discs and been using them daily for 9 months. The humming noise went after the pads bedded in and they haven't warped.  It's not unheard of for VAG discs to warp easily though, so you might be able to get replacements if they were fitted correctly.

If yours were also not L&R handed when you bought them, that is also a case for a refund/swap because it means one disc runs a lot hotter than the other.  I think I got a pair of Rights.  I did ask the dealer about it but VW only list one part number for both sides.

I fitted lots of stuff at the same time to be honest. Alloy hubs, bearings, lower arms, lower ball joint, track rod end, ARB. I have a decent dial guage at work so i'll have a play with that maybe. Do you think it would show up?

Mine aren't handed that's for sure, both drivers side in effect. Perhaps i should approach AKS for some advice 

Thanks for the advice chaps.

[pudding]

OK, quite a few variables there then.  Sure it's not just tyre imbalance?  A weight or two fallen off a wheel?

Yeah a badly warped disc would show up as some pretty funky run out on the gauge.  Can be sorted with a brake disc lathe though.

Pretty poor of VW selling 2 driver's side discs!  You can clearly see the vanes are directional by the drilling pattern!

[colesey]

I think the CS discs come from the same supplier as the TT/RS 370mm ones and overheating on track from the wrong sided cooling vane is an issue on those cars.

[exodus_ste]

Funnily enough, i think there is a wheel balance issue also. Only at 80-85 (on the Autobahn) does that show up as slight wheel wobble/vibration. Or perhaps that is also a warped disc causing some funny issues when at a higher speed?

For sure, for the price of the discs you'd expect a right and left! I'll ask AKS and see if they have had any other probems with this kit.

Thanks again guys

[pudding]

Yeah, ~85mph is where I notice poor tyre balancing the most.

It could still be a warped disc, but wheel balancing is a cheap potential cause to eliminate in the meantime.

The disc handing thing is very weird.  I can't remember if there is an R or L stamped into mine, I'll have a look next time the wheels are off.  I can't believe the company who made them for VAG only make one side, so it must be an admin cock up at VAG somewhere.