Would you accept these discs?

'Baught' strange spelling (not typo as done twice)

Being concerned about ventilated discs with different thickness sides, and on the thinner sides looking "like they've been turned by a ham fisted blind man" can hardly be described as "being overly fussy about the cosmetic appearance"

Those are not cosmetic faults, they are machining and design faults, which will affect their service life if nothing else. Personally I don't think they were originally made for an E38 740i. Delphi is a reputable Co. I'm sure their pattern discs would look identical to the originals. They would know as well as anyone else with any sense, that the two flanges should be the same thickness. IMO somebody has modified discs designed for a different vehicle. Turning one side so the disc is the right thickness, and runs in the correct place relative to the caliper. It's the only logical explaination of why one side is thinner than the other.

One thing I can say for certain. I'd never put similar discs on a car of mine, even if I were given them for nothing, and to charge £40 pounds for them, when equally as good quality new discs can be baught for £35 is just adding insult to injury IMO.

Personally I'd send them back, telling the supplier exactly what I thaught of them, and demand my money back, including the return carriage cost. Mike.

One of Mike's endearing little foibles. ;-)

Perhaps it's an old english past tense spelling?

You're right it's not a typo. If I think about it I spell it right. If I don't, I always get it wrong. I just don't seem to be able to cure myself of the habit. I suppose it's because phonetically an 'a' seems more appropriate than an 'o'. That's my excuse anyway. At least I don't refer to a cars breaks. :-) Mike.

Something like this has come up on another group with an E39 540. Seems there are two types early and late. Fit the late ones to an early car and the disc rubs on the caliper...

Thank you Dave, but it's not really my fault you know. :-) Problem is that baught looks more right to me than bought, so I don't notice it in the way I normally notice spelling mistakes. If I were picked up on it more frequently maybe I could get out of the habit. Come to think about it I make the same mistake with brought, but it's not a word I use as much.

Or maybe it's a long forgotten alternative spelling which might allow me to continue using it. Must check. :-) Mike.

LOL - you're right - 'breaks' is positively cringe bringing!

You can't try that one unless you're 96 or older! (and then I'd hope you weren't messing with brake discs - or for that matter even driving!). If you're going for the phonetics, surely it should be bawt or bort? But then we'd be getting into SMS language and that's destroying our illogical old English as each day passes. Just you see the state of the Oxford dictionary in 10 years.

Actually - on the OP subject of discs, I note many responses are going on about the fact the inside and outside sections of the disc are not equal thickness. As far as I know - this is not necessarily wrong. I haven't played much on BMW's yet as up to recently I was a VW man - but some Gold models have this and when this is the case, the inner brake pad is smaller implying that the inner calliper applies less pressure than the outer - meaning less wear and therefore thinner disc section. Are your brake pads the same size? If not and the smaller one works on the thinner section - that seems OK to me. Best David

To me I see "au" as either "oh" as in french, or "ow" as in german.

Naught for example up north is pronounced "nowt" and you'll find that southern England words have more in leeping with French pronounciation while northern words are more in keeping with German and Scandinavian.

To go back slightly OT, the pads are the same size.

Yup, due to the influence of the Vikings in central and northern england, and the Normans in the south. We're really just a motley bunch of mongrels. :-) Not that I know much about english history.

Just a thaught, spelled with an 'a' you'll notice. As is fraught and caught, so why bought with an 'o'? The pronunciation is similar Mike.

You seem to be the minority here Jack.

It's not cosmetic. They are either manufactured (or remanufactured) WRONG. The two plates that make up the ventilated disk are supposed to be pf the same thickness. The brakes will not operate correctly when the get hot otherwise.

Brakes are not a bling-bling cosmetic part. They are probably the greatest single safety feature effecting how the car will be operated.

I would never put crap brake parts like the rotors in those pictures on any car (even yours).

Oh, and I don't see how accepting garbage parts at full price somehow lowers the price of parts for others. It just encourages crappy part sellers to continue to sell crappy parts.

Huh? Care to explain the physics of that feat? The caliper squeezes the disk (rotor) between the two pads.

Also, if the pad is of a smaller size, given the equal pressure applied on either side of the disk, the pressure per square inch would actually be higher causing friction and heat generated to be more concentrated.

But to get back to the OPs BMW brake design, I am 100% certain that the two halves are intended to be the same thickness. That way the will expand and contract equally.

Just to be clear Fred

I did say that I would return these parts if they were warped or if the thickness asymmetry was not per spec.

I also said that I would not return them for cosmetic reasons such as greasy fingerprints, crumpled boxes, or evidence of being previously installed.

Have a nice day.

Because one or more of us motley bunch who thought maybe they could write wrote it down wrong and it's stuck ever since. Some words are spread by the written word so they look the same but sound different and others are spread by speach so they sound the same but look different.

OK, gotcha. Same here.

U2

Ok, I got some new new discs from brakeparts.co.uk today (they should have arrived yesterday). They look new with cellophane over them although the packaging in general is a bit battered. The faces are perfectly flat with the usual small lines on and they make the delphi ones look like they were made in backstreet turkish shed.

However, there's still the difference in thickness between the inner and outer face. I think I'm happy to fit them but I guess if they warp I'll know to go to BMW next time. I usually go to the dealer for discs and this is the first time I've skimped.

Incidentally buypartsby.co.uk said they'll take their Delphi discs back but so far I haven't been refunded so that'll be another thing I have to keep an eye on.

I always get ATE discs from Eurocarparts. They are OEM makers and the replacements seem identical to BMW ones (as you'd expect), but much cheaper. I've fitted many sets across the years without problems. Except that they don't last any longer than BMW ones. ;-(

Must say it's the first time I've ever heard of discs with different thickness faces. I still can't see how they can adequately cope with the difference in heat absorbtion and dissipation.

I think I'm happy to fit them but I guess if they warp

I don't think you'll have any problems with them. I've baught 3 pairs of discs from Brakeparts for different cars. They seem at least as good as OEM ones. Mike.

Just to hopefully add a final note to this thread, buypartsby (or autospares group or sutton motor factors) picked up the first set of discs and refunded my money with no questions asked but no apology either.

I got a confirmation email from brakeparts from their whizzy website in which it said if I had any questions to email them back. Well I did email them but heard nothing at all so it seems yet another company that claims to have wonderful customer service but fails to back it up.