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Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sat Jun 01, 2019 4:57 pm
by 1925TT
Have a set of Rocky mountain brakes for a TT, but no rods. We can build rods, but we are playing with the idea of using cable instead. Not sure if anyone has given this a shot before and if they ran into any issues.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sat Jun 01, 2019 7:04 pm
by Susanne
The rods give you an option of a POSITIVE release... with cables, you're relying on a spring, and if you need to get that pedal up to stop a single wheel lockup, and you're hoping a spring will save you...

Thats why they used rods. They knew you may need to pull up that pedal to unlock a sliding wheel, and springs and cables, while fine on modern juice brakes, wouldn't provide a negative "pull" to maybe save your butt.

You're talking 100 year old technology... please remember they also had safety in mind, but it was for the technology your car had. My car's run fine with rods AS LONG AS I inspected it and serviced it.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sat Jun 01, 2019 7:10 pm
by CudaMan
I'm using a home-built hybrid equalizer / cable setup on my period (not reproduction) AC brakes. I plan to use the same setup with my early reproduction Rocky Mountain brakes (whenever I install them). :)

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sat Jun 01, 2019 7:33 pm
by JvanMaanen
I tried this on my 22 coupe with original AC's and hassle shocks, found it easier to use rods and guides, the routing of cables was somewhat difficult, you could just bend the rods. Also the rods allowed me to put a little pressure away from the wheel on the brake shoes, giving me some much needed space.

Jim

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sat Jun 01, 2019 9:47 pm
by RajoRacer
Original Rocky Mtn. Brakes used cables.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sat Jun 01, 2019 10:31 pm
by Pops
Hello Steve: Are you saying cables are better or just as good as rods?? What is prefurded ??? Thanks

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sat Jun 01, 2019 11:01 pm
by RajoRacer
I've run both and they're both pretty equal - cable actuation relies heavily on the equalizer assembly design - rods & the currently available equalizer are pretty straight forward in the Engineering Dept.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sun Jun 02, 2019 11:18 am
by Mark Gregush
I am thinking that if X amount of force is being applied the rods will more directly apply that force. That being said, I would use ether. If I was using an original set of real Rocky Mt brakes I would use cable as they were made to use, modern I would use rods. A friend has the modern small drum AC's on his car, he did set them up with cables and have been working fine. I have big drum repo AC/Rockies on my 21 that I made my own equalizer and run rods, they work fine. This is a bad photo but is the only one I have right now. While it hangs off the parking brake cross shaft it goes under it and is independent of the shaft.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sun Jun 02, 2019 4:41 pm
by Scott_Conger
As stated before, wire rope was the original standard.

That said, a modern mechanic, not versed in the use and termination of wire rope could easily get into real trouble compared to using solid threaded rods and clevis'.

This is NOT a recommendation or perjoritive on either method. Just know what you're doing and understand the system that you choose.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sun Jun 02, 2019 10:05 pm
by Original Smith
Rocky Mountains use a 3/16 cable. The problem is most people assume, incorrectly, that Rocky Mountains used rods. Do your home work! Rocky Mountains were never designed to use a rod, nor did they have an extension on the lower portion of the brake pedal. The current edition of Rocky Mountains is a combination of 1926 style AC brakes, and Bennett brakes.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Mon Jun 03, 2019 9:01 am
by Dallas Landers
I have been following this thread because I have an original set of RM for my TT. Larry, how was the peddle set up without the extended peddle to hook to? I have instruction sheet from modern RM's. I have just the brake parts and no equalizer. Not to hijack OP but just gathering info.
Thanks Dallas

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Mon Jun 03, 2019 10:48 am
by Tiger Tim
Dallas Landers wrote:
Mon Jun 03, 2019 9:01 am
how was the peddle set up without the extended peddle to hook to?
IIRC it’s a metal sleeve that clamps to the pedal just below the floor, then I believe a short rod that terminates in a pulley near the U-joint. The rod has a turnbuckle in it and a bracket that keeps everything from flopping around. There’s a single cable to both brakes that runs in a “V” through that pulley.

Come to think of it, aren’t there similar rigs designed to make the rear drums into service brakes on late Ts?

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Mon Jun 03, 2019 11:17 am
by RajoRacer
I'll get a photo of my original R.M pedal linkage later today & post it.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Mon Jun 03, 2019 8:57 pm
by RajoRacer
Here's what an original R.M. brake pedal clamp & linkage looks like.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Mon Jun 03, 2019 9:20 pm
by Dallas Landers
Thank you Steve. I think even I could make that.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sun Jun 09, 2019 12:58 am
by Original Smith
Steve: I sure wish I had those parts you just posted. Those kind of parts probably got scrapped by the 100's because no one knew what they were for!

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sun Jun 09, 2019 9:51 am
by Tiger Tim
Original Smith wrote:
Sun Jun 09, 2019 12:58 am
Steve: I sure wish I had those parts you just posted. Those kind of parts probably got scrapped by the 100's because no one knew what they were for!
Not to commit someone else to a job but I’m sure a bunch of folks around here could whip up copies of those in their sleep.

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Sun Jun 09, 2019 10:04 am
by TWrenn
On this subject..and I'll also post in the classifieds if anyone has an RM set for sale or even A/C brakes please PM me. I plan on putting one or the other on my '25 Fordor. Thanks

Re: Rocky mountain brakes, has anyone used cable instead of rods?

Posted: Mon Jun 10, 2019 12:53 am
by Original Smith
I had the pleasure of seeing an original Rocky Mountain brake assembly on a TT rear end this weekend. What a pleasure1