Cutting brakes

[Snoopy]

Well, I'm looking to put in some cutting brakes and was wondering what you all have done to do it.

I'm looking at one of two systems. Below you'll find pictures of 2 different setups. Think of them like a double-barrel shotgun, one is over-under, the other is side-side.

How they work (for those who don't know ~ and I didn't know until yesterday)
The single brake line that usually goes to the rear axle is fed into the cutting brake assembly. This allows you to have normal operation of the brakes until the cutting brakes are used. There are two outlets from the assembly, one to each wheel (think of it like a big t-junction)

Then, when you use the cutting brakes, the side you are operating isolates itself from the system and a built-in master-cylinder (located in the cutting brake mechanism) supplies hydraulic preassure to the side you've designated ~ locking the brake on that side.

These systems cannot be locked 'on' ~ they are strictly momentary unless modified. There are 3 different sizes. 5/8" bore (for drum brakes), 3/4" bore (for disc brakes), and 7/8" bore (for really big disc brakes).

Version 1:

The side-by-side version has two sticks, one next to the other. To engage the right brake, simply pull the right lever ~ for the left brake, pull the left lever.


Version 2:

The over-under system has one stick. Pulling back engages the driver-side brake. Obviously, pushing forward engages the passenger-side brake.

Here's the trouble. The side-by-side version seems to be the one most would go for ~ but the biggest size bore it is available in is 3/4". The over-under version comes in all sizes including the 7/8" bore, which I'm more interested in.

I'd rather have the side-by-side version since its intuitive AND allows me to pull both levers at the same time (kinda a make-shift, momentary e-brake ~ cops). But my question is weather or not the 3/4" bore unit would work on a Buggy w/ a Ford 9" and TSM disk brakes.

These units are built for sand rails & Dune Buggies, and I'm have no experience with what size the brakes are on those. Will need more capacity than the 3/4"?

 

[I Lean]

The 3/4" bore ones seem to work fine with most brake setups.

If you want a more intuitive feel with the single lever style, mount it sideways. It's not as easy to move, but pushing it to one side locks that wheel.....

 

[harkinoff]

I use version 1 , 3/4, Got it from Andy here on this sight... they work fine on the Scout so far, I'll try them out alot more this weekend

 

[Caleb]

I have a Version 1-3/4" in my buggy...dual handle (one for each rear wheel)...I have yet to drive my buggy but it does seem to lock them up pretty good...

and BTW, where are you finding the 7/8 bore ones? on all the sites I have found they only list a 5/8 and 3/4 bore...

 

[Snoopy]

and BTW, where are you finding the 7/8 bore ones? on all the sites I have found they only list a 5/8 and 3/4 bore...

http://www.chirco.com

Do a search for "cutting brakes"

 

[rockdog]

I don't have cutting brakes, but wheel with someone who does. On a lot of occasions (sp) he has to use both rears locked to turn. Like when your in loose rock or dirt. Anyway , thats something you might want to consider.

 

[J Kimmel]

www.cncbrakes.com

FWIW, I spot in the ProRock mod stock class, right now we have arbs and cutting brakes. Two levers that you pull up, each controls one wheel, and we have 4 wheel dics. Outside handle controls the drivers rear tire, etc. In theory with the rear axle disengaged and the locker off, lock one side and you should be able to pivot right around. Well it hasn't worked very well at all, and we're changing the whole system over, but the main change is we are going to a "staging brake," from CNC, it locks the whole rear axle. We are installing two, they are 3.4 bore and one for the rear axle, and one for the front to help rear digs.
Locking both rear brakes up really lets the whole vehicle pivot much tighter to make the turns needed to be competitive.

HTH

Jeremy

Oh also the staging brakes are a push lever, as opposed to a pull, much easier. You can mount them so at full lock your arm is locked out instead of trying to pull on them as hard as you can, the added leverage helps

 

[Snoopy]

www.cncbrakes.com
We are installing two, they are 3.4 bore and one for the rear axle, and one for the front to help rear digs.
Locking both rear brakes up really lets the whole vehicle pivot much tighter to make the turns needed to be competitive.

Two eh? So the front one won't be used at full lock-up, just enough to give more bite to the rear tires?

I saw a couple a couple buggies at CalROCS that would lock-up the whole rear axle and it didn't seem that they could pivot as easy

Hum.

 

[J Kimmel]

One lever to lock the front axle, one to lock the rear axle. Not sure about the Calrocks rigs, but from my experience this season, and believe me we've struggled with it, the guys in our class at least that can pivot the best lock up both rear brakes.
The front lever is to lock the front axle, disengage the front axle, and dig the rear axle over where you want it. Weather to pivot better or line up better for cones that works well too.

 

[josho]

snoop,
i just got mine from CNC, and i have the 2-lever design. i talked to CNC directly and they told me the 3/4 were for disk brakes, and the 5/8 were for drums. i am running mine to a 14b rear with the toy disco, i'll PM you when i get her moving.

el josho

 

[EZRhino]

I assume that it is pointless to install cutting brakes if you have a spool. So would open/ARB'ed diff's be the only real candidate? What about Detroit Lockers, Lockrite, etc?

EZ

 

[I Lean]

I assume that it is pointless to install cutting brakes if you have a spool. So would open/ARB'ed diff's be the only real candidate? What about Detroit Lockers, Lockrite, etc?

EZ

Auto-lockers work fine with cutting brakes, as long as that axle is not powered.

 

[Caleb]

I assume that it is pointless to install cutting brakes if you have a spool. So would open/ARB'ed diff's be the only real candidate? What about Detroit Lockers, Lockrite, etc?

EZ

cutting brakes will still work with a spool, obviously just not nearly as well as with a selectable locker...