Apex1.0

As long as you dont have melted pad build up on the rotors when you swap pads you will be fine. When you bed in the new pads, it will eliminate the old pad transfer layer.

If your brakes pulsate, shudder, judder, vibrate or whatever with the old pads, they will with the new pads too. Replace the rotors when changing pads.

B serious

Beefystud is correct that a fresh rotor surface is the MOST CORRECT way to bed in a new pad.

But...pulsating is from pad deposits and martensite on the surface of the rotor.

He's right that brakes are more likely to develop a pulsation if the pads are attempted to be bedded on top of another pad's layer. Because pads most effectively bed on a new surface. I've seen this on other cars....never a S2000, but it is more likely to occur.

Brake pad deposits will cause pulsation that may or may not go away. Once you got that concentration of carbon on the rotor, though....the pulsations will likely stay even after pad re-bedding or rotor surfacing.

In any case....I don't think I'd ever re-surface a rotor in 2017. But....if his rotors are not pulsating...and he gets a new set of pads...and he doesn't mind the time and cost involved in resurfacing...then, yes...he's correct to resurface the rotors rather than just raw dog the new pads on top of a used rotor surface.

RedCelica

Not entirely true, but depends on the condition of the rotor. I switched from carbotech to hawk on the same rotor (no resurfacing done) and did not experience any shudder. Carbotechs do need to fresh surface, so if I were to go back to Carbos I'd use new rotors.

You said you did bed them. What was your bedding process?

starchland

This is highly pad dependent I think. Remember the op is asking about a track car an agrressive pad will clean up a less aggressive pads mess from what I've seen

s2000Junky

I always use slotted rotors, they self clean. Its just not an issue. Quicker bed in, self resurfacing and better more consistent performance allowing a channel for gasses and debris to evacuate rather then build up. I dont see any benefit to using stock rotors when you can get a set of slotted for under $150 for 4. I just replaced my rear slotted rotors for $64 shipped to my door from ebay. The only downside is more dust on the street if its a shared duty street/track car.

Car Analogy

If rotors are still good, and you don't want to repace them, you can clean up old pad material and create a good surface for new pads to bed to by using a brake disk hone. Just chucks into your drill. Got mine from Amazon.

You don't have to drive to machine shop in the middle of your brake job, no waiting around, no lost rotor material. Just a couple min on each rotor and you're good to go.

B serious

I buy gangs of centrics or whatever is on sale at rockauto.

I usually dedicate a set of rotors to my Carbotechs.

Once they are wrecked, I throw them away, install new ones, and continue living my life.

For my street pad set...I require MASSIVELY good brake feel. So I just generally put on new rotors with new pads. But...at a rate of like 5K street miles a year in my S2000...I don't remember having to do this. I do it for my daily, though.

lovegroova

My experience with slotted discs was that the pads wore significantly faster, so I returned to using non-slotted items.

A good tip is to clean the discs with some brake cleaner, a light sanding and wire brushing when switching between pad compounds. Result, no shudder and good braking from the off.

mikefifth

Hi gents. Just revisiting this for confirmation.

input much appreciated.

plan is to run until they crack and will wet and dry the discs before the new pads are mated up.

Mugen_is_best

I bedded a new set of pads (PMU HC800+) on a set of old rotors. I changed pads front and back. The rotors had maybe 10k on them before I changed pads. They are oem as well. I haven't experienced any issues; worked perfectly.