Are calipers manufactured to set sizes or did I just get lucky!

[Al Weyman]

On my old yellow tank (Camaro) the rear calipers were sticking and as they had been on a few years and were originally purchased from a scrap yard and came off an old 7 series BMW I thought I had better change them.

I bought a bair of Bremsport lightweight aluminuim calipers with competition pads for a fair price off eBay and set about at the weekend changing them full expecting to have to do much modification or even fabricate some new brackets as these were off the front of an Astra (they are going on the back of my car). Anyhow to my surprise and delight apart from a couple of spacer washers these things just bolted straight up to the original brackets that I fabricated 12 or 13 years ago and even sit perfectly on the disc.

Too much for coincidence? Which got me wondering, do manufactures make calipers to a standard set of parameters or did I just get very lucky?

Incidently once I have made sure everything is OK the Astra mounting brackets that came with the calipers can go to a good home if anyone wants them.

[graham bahr]

Originally Posted by Al Weyman

Too much for coincidence? Which got me wondering, do manufactures make calipers to a standard set of parameters or did I just get very lucky?

.

i dont think there are STD sizes as such, more likely just serveral sizes that are common just like wheel PCD's

[Dave Brand]

Originally Posted by Al Weyman

Too much for coincidence? Which got me wondering, do manufactures make calipers to a standard set of parameters or did I just get very lucky?

There are no standards that I'm aware of for caliper dimensions, but the brake manufacturers will tend to stick with their own set of parameters. In the interest of interchangeability, mounting dimensions tend to be standardised; the base model of a car may use a different caliper to the performance model, but with the same upright, & in some cases calipers from different manufacturers are used on the same vehicle, which requires standardisation between brake manufacturers (e.g. Peugeot 405 used both Teves & Bendix calipers). For the aftermarket manufacturer it makes sense to use the standard mounting points if possible rather than having to supply mounting adaptors.

I wish there had been a standard for calipers &, more importantly, pads....it would have made my working life a lot easier!

[Ericd]

I was an engineer with Brembo for a few years and I can agree that there is no industry standard. There are general standards that each manufacturer holds to for a given set of vehicle parameters (weight, heat capacity, worst case etc).
Then if it is a clean sheet design or based on existing tooling will make a big difference.
The actuation side, hydraulic specs and boost, pedal ratios will also dictate the end development of rotor and piston sizing. Its a bit of chicken and the egg with brake calipers.

-Eric

[Al Weyman]

Well I finished the conversion today and the pedal feels good and the brakes dont stick so all ready for next season with that car. Also saved a fair bit of unsprung weight.