Brake disk thickness

It depends what they are made of, I would say it was something a bit better than standard road cars. With brakes I wouldn't mess around, if they need doing then have them done!

They might just be very hard. The discs on Mazda MX-5s, for instance, barely wear at all. There's no lip on mine after more than 61,000 miles.

| | They might just be very hard. The discs on Mazda MX-5s, for instance, | barely wear at all. There's no lip on mine after more than 61,000 miles.

Thats good news then I have an MX-5 and it's just done 16,000 miles so still good for a while longer :-D The ones on the Ka tend to wear quicker but then maybe thats the way my wife drives it, the clutch is up for replacement after 44,000 miles, she is always running late and tends to drive a little hard.

Stu

Depends which Elsie you have.

Have a look at:

FFS - you can run an Elise, stop being a stingy bastard. Do what they say, I'm sure it's for your own safety, assuming you actually use the car up to spec.

-- Stuart

Avoiding spending £600 before it's really necessary is very sensible. So is learning all you can about brake disks. Something I won't do from you. Maybe you should stay in bed? It's for your own safety, I'm sure.

Avoiding spending £600 before it's really necessary is very sensible. So is learning all you can about brake disks. Something I won't do from you. Maybe you should stay in bed? It's for your own safety, I'm sure.

Stevie ( snipped-for-privacy@spam.com) gurgled happily, sounding much like they were saying :

Don't forget they'll be vented, unlike your Fester disks.

They may have allowed a couple of mm of wear, over a disk maybe 10mm thick.

The actual wear surfaces on the vented disks may well be actually thinner than the Fester ones, but the disk overall is thicker, because of the vents down the middle.

(Mk2 Fester -> Elise... Chalk -> Cheese...)

The normal recommended wear limit on vented disks is 2mm and that's well on the safe side anyway. 4mm isn't normally a problem. If it was a racing car they'd be that thin to start with to keep weight down.

I see no reason why resurfacing a worn disk can't be done. There's nothing particularly special about the car compared to any other.

-- Dave Baker

Good point. Each side of the disk is only about 5.8mm (worn). That puts it a little more in perspective. But if I'm looking one side at a time, I'm now only 'allowed' 0.55mm wear! Crazy! Especially if Daves figure of 2mm 'usual' and 4mm 'acceptable' are correct. (Thanks for your post Dave, that's exactly the knowledge I was looking for.)

Steve

Stevie ( snipped-for-privacy@spam.com) gurgled happily, sounding much like they were saying :

A Fester and an Elise are rather diffferent kettles of fish, and there's a big difference in the amount of heat that is likely to be assumed to be going into the disks. An Elise is going to be used harder than a Fester.

You're also looking at a disk with the heat now trying to dissipate over only 6mm of thickness - that could easily cause buildup - I know I used to get fade something rotten on badly worn vented disks on the front of a CX.

I've also seen vented disks worn so thin that they'd broken through into the venting.

How early is your Elise?

It's a 2002 S2 with the original cross drilled iron disks. It's done 35k miles of standard abuse and 3 track days.

They have lost between 1.36-1.56mm each. So over the 1.1mm service 'minimum', but well less than a more standard 2mm.

Thats one hell of a step up MkII Fiesta to Lotus Elise!

I assume that they are vented discs by the measurements given. Therefore the thickness of metal between the vent and the braking surface is critical. I have seen them crack if worn thin enough, allowing the pads to lock up on the vents, locking the wheel. On the other hand. Lotus give these specs for a car which is designed to be raced on a racetrack. I doubt you are working the brakes nearlly as hard as this. However I would like to see at least 6mm of metal either side of the vents if I were driving the car. Skimming is all well and good on a scored disc, providing it leaves enough material for a reliable disc. (The caliper exerts immense pressure on the vents). Obviousy skimming a disc will make it thinner.