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Comment by rconti | Hacker News Reader

Labor costs are just insane. I've gotten quoted $500-$1000 per axle (yeah, $1000-$2000 all-in) for brakes on my BMW. And it takes me maybe 2 hours in my driveway (at beer-pace) to slap on the couple hundred dollars in parts.

Brake pads easily last 60k miles and cost maybe $50 per corner, and the rotors are about the same but last twice as long (though it's recommended you replace at the same time, not always necessary).

Of course, once you get into drilled factory rotors on an STi or M3 or something, you're gonna hit the $200-$300+ per corner for rotors pretty quickly.

I dunno, I've just always find the margins on brake work seem insane compared to anything else.

OTOH, I also find the German marques' brakes last far longer between changes than the Japanese.

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If you replace brake pads and you are going to keep your rotors have them turned down a tiny bit to ensure roughly double the wear life on your brake pads. If they are too thin to be turned down safely then you'll have to replace them anyway.

I don't know of many places that still turn rotors, many of the big shops stopped and so did some smaller, unless they're specialty I always buy new, partially the reason I do it myself.

That's mostly a decision to increase turnaround speed on their bridges, it is faster to swap a rotor for a new one than it is to turn one down. But if you're cost conscious enough to replace your own brake pads and you don't want your new shiny pads to be just as bad as the old ones after a couple of weeks (as in: grooved, they will likely still be thicker) then turning the discs is a good option. Where I live this is still pretty easy, it might be harder in other places to find shops that will do this. Cost me about 10,- / disc.

I'm still not really clear on why it matters. If anything, grooved rotor/pad combos have more friction surface :)

I just swapped pads last weekend for a track day, my rotors are grooved and should be replaced next time I have to replace my street pads, but once the pads are bedded in, they still grip amazingly well.

It essentially cuts life from the pads, it does not change your braking distance.

Just as bad in a few weeks seems like a bit of an overstatement then, unless you're replacing your pads based on their wear rate instead of how worn they are

Depending on how bad your disks are that can really add up.

> That's mostly a decision to increase turnaround speed on their bridges, it is faster to swap a rotor for a new one than it is to turn one down.

I used to turn the rotors on my European cars, but about 10-15 years ago the alloys started warp after being turned just once or twice. Easier to just pay to replace than take the risk of doing the labor twice.

Nobody turns brake rotors in the US anymore. If your price sensitive, you'll just buy a Chinese-made rotor for about what turning would cost. If you're not so price sensitive, chances are good that your brake rotors use an alloy that the old brake lathes can't cut anyway.

I used to get rotors turned. Then I stopped because it was a pain. Unless a rotor has been grooved by a completely worn brake pad (i.e. the backing plate and rivets made contact), I haven't seen any difference in performance or longevity.

My old STI had cheap brakes. Brembo rotors are like $50-70ea. Pads are about $60 a pair.

Yeah, that was normal for even higher-performance cars until, I think, 2008ish where Subaru went to the Brembos on the STI.. and around then (2006 competition package maybe?) BMW went to drilled rotors on the M3.. everyone wants to sell the bling now :)

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