Trailer brake drum sizes?

[Mike B]

Hi All,
I have read different post on the site talking about the different size brakes that some trailers have.
Is the difference the size of trailer or build date? What trailers have 10" drums and what have 12" drums. Does anyone know what size disc the new Classics will have?
I know that both my 1976 31' and 1977 23' have 12" drums on them.
Thanks
Mike B

[Inland RV Center, In]

Mike.

The disc's that the factory is using are 12 inch.

Andy

[Mike B]

Thanks Andy,
I thought that the factory might be using 12's instead of 10's but didn't know.
Was there any particular sizes or years when the factory started using the 12" drums instead of 10's.
Thanks again
Mike

[Inland RV Center, In]

Mike B.

Airstream went to 10 brakes during a severe lean time.

Other than that Airstream trailers use 12 inch brakes and the Argosy trailers used 10 inch brakes on some models and 12 inch on the others.

What size is easily determined by looking at the backing plate mounting flange thats welded to the axle.

If the flange is square, it has four bolts, making it 10 inch.

If the flange is round, it has five bolts, making it 12 inch.

This is true for electric or disc brakes.

Andy