Rocky Mountain brake drums

Dan/Kzo

Dan/Kzo

Member
Today we had our spring safety check and a couple of the 1931 A's had the Rocky Mountain cast drums in the front. The question among us today was if Ford ever put this type of cast drum on the rear or were they only put on the front.
 
fordgarage said:
Yes, there are original Ford cast iron drums, both front and rear. I really don't understand where this common terminology of "Rocky Mountain" came from. They were just a step in Ford's evolution to cast iron. By 1932, all Ford drums were cast iron, and (thankfully) stamped steel was over.

The 1931 cast rear drums were not spoked like the fronts. They were solid.
1931 and 1932 Ford cast drums were virtually identical in format and appearance, only Model A were 11 inch and 1932 and beyond were 12 inch diameter.

1931 and 1932 Ford cast Iron Front Brake Drums
Click to expand...

Did any A's come with the spoked cast drums from the factory? Did any Cast drums come from the factory on A's" Why two different styles (spoked and non spoked)?

I always thought the name came from the after market rear brakes that were sold to be installed for better "mountain" braking then the "transmission" brake normally on T's.
 
Mike, I'm gonna try to answer part of your questions by what I do know. Yes the drums (both front & rear) were cast. Yes the fronts were spoked but the rears weren't. I can only speculate that the fronts were spoked to aid in cooling but for the rears, due to the design of the emergency brake probably did not lend to being able to use the spoke design on those. The original-style rear cast drums are similar in aesthetics to what the repro cast drums look like however the location of the strengthening rib and it's shape are a little off on the brand of repro drums I use. I have not studied all the other brands in that regard but if you want to get a basic idea, look in the J/S to see a sectional crossview of the original cast rear drum.

I, like Vince don't know where that name came from on those. I suppose it is possible that Rocky Mtn's business had fallen off after Model T sales had dwindled and so they became a vendor to Ford on manufacturing these drums no different than Zenith, Sparton, etc.? I do know that I have looked at several spoked drums looking for a name cast into it and have never found anything. Maybe others have??
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The cast iron drums weigh more. If you tap on the stamped steel ones, they will sound "tinny" whereas the cast iron ones will sound more solid or make a "thumping" sound.
 
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