advice on discs

going to change me discs all round on me n/a whats the best oem ones or grooved and where is the best place to buy either.

G3 gooved are nice Traders on here sell them

we can fit them and buy them for you mate

OEM are absolutely fine for the job, grooved/drilled discs are inferior to OEM in terms of braking capability. Steve Manley at Inchscape Oxford is the cheapest supplier of these.

OEM are absolutely fine for the job, grooved/drilled discs are inferior to OEM in terms of braking capability. Steve Manley at Inchscape Oxford is the cheapest supplier of these.

grooved/drilled discs are inferior to OEM in terms of braking capability.

Why is this homer? I keep reading that OEM disk's are better but how/why?

Why is this homer? I keep reading that OEM disk's are better but how/why?

The grooves in discs are to aid cooling, however, they also decrease the amount of contact area between the pad and the disc, effectively reducing the braking power.

This of course is the most important aspect on the road as there is almost no point during day to day driving where the disc is overheating. The time when you *really* need to use them hard (i.e. unexpected hard stop) you want the maximum braking force available from the brake system.

On the 'small' OEM discs with Chris Wilson fast road pads I've done a hard stop from 180mph to 30mph without experiencing any fade, therefore in this circumstance grooved discs would have only served to increase the braking distance.

On race applications it's obviously a completely different scenario.

Thank's for that

The grooves in discs are to aid cooling, however, they also decrease the amount of contact area between the pad and the disc, effectively reducing the braking power.

 

This of course is the most important aspect on the road as there is almost no point during day to day driving where the disc is overheating. The time when you *really* need to use them hard (i.e. unexpected hard stop) you want the maximum braking force available from the brake system.

 

On the 'small' OEM discs with Chris Wilson fast road pads I've done a hard stop from 180mph to 30mph without experiencing any fade, therefore in this circumstance grooved discs would have only served to increase the braking distance.

 

On race applications it's obviously a completely different scenario.

I've got to be honest here mate, i find that hard to believe, yeah ok there is a marginal difference in surface area in contact with the pad, but surely a groove will offer more fricton when passing the pad than what a smooth surface will?

I've got to be honest here mate, i find that hard to believe, yeah ok there is a marginal difference in surface area in contact with the pad, but surely a groove will offer more fricton when passing the pad than what a smooth surface will?

How would that work? Less surface contact = less contact to the disc = less braking force. The groove is there to allow heat to be released from the disc surface, nothing more.

surely a groove will offer more fricton when passing the pad than what a smooth surface will?

As Homer has said, the groove isn't there to provide more friction.

How would that work? Less surface contact = less contact to the disc = less braking force. The groove is there to allow heat to be released from the disc surface, nothing more.

come on, we are talking about such a small difference here, yes you are right the groove is there to allow the hot gasses to escape without pushing the pad away from the disc, the groove also helps to remove any glazing of the pad.

As Homer has said, the groove isn't there to provide more friction.

no its not, but its a handy side effect wouldn't you say?