Mad Hammer

iTrader: (55)

I have black diamond cross drilled and grooved front discs. Should I notice a fair amount of judder with these?

Cheers

Clive

greasemonkey

Not if they're not warped. Sounds like they are.

ozzy

From what I've been told warped discs are a bit of a tall tale. Usually the judders from excess deposits on the disc surface or if the discs have cracked it can cause a raised points on the surface.

Also, if the discs are new the coating can take a long time to scrub off causing excess judder.

Not an expert, but just picking up what mechanics have told me when I've been trying to diagnose some judder on my own Godspeed kit.

Stefan

Blue_Boy

How much is a fair amount?

Does the wheel feel like a vibrating pad from a games console or is it more like a Go-Kart going over small speed bumps in the road at about 60mph???

If it's the Go-Kart one then they probably are.

Mad Hammer

iTrader: (55)

Just vibrating through the wheel under harder braking. They have only done about 2000 miles since I fitted them. It certainly stops ok!!!

stockcar

what pads are you using some makes will cause this........

Mad Hammer

iTrader: (55)

Pagid pads

Blue_Boy

Well, don't sound properly warped then.

Check out your wheel alignment and you may want to change the pads at some point (now were's that thread I was looking at with recommended pads), I'll have a search and forward on if I find it.

Monitor it though - if it's getting noticeably worse over 3-4 weeks, then it is warping.

Mad Hammer

iTrader: (55)

Since comments on here I have realy been taking notice more. The vibration only happens with light to medium braking or extemely heavy! By light to medium I mean say slowing down from 60 to a T-junction (normal braking), the vibration is very, very slight. I may be making more of it than I should. Does anyone else get this with grooved/cross drilled discs?
On Heavy braking I expected it from when I fitted them, pads digging in to the grooves? Before anyone says, yes I did bed them in - 200 miles before even attempting to hit them hard.

ozzy

Yes, I get a very very slight vibration (well more like the steering wheel wobbling from side-to-slide ever so slightly). The mechanic who drove my car on Saturday said it was to be expected.

He also said that he's never seen a 'warped' disc in over 15 years and 99% of the time, the warped disc turns out to be uneven pad deposits. The other 1% was cracks near the grooves or drilled holes causing the disc to split and lift - giving the vibration as if they are warped.

Stefan

Mad Hammer

iTrader: (55)

Thanks for that Ozzy, sounds just the same.

Clive