Tailshaft mounted handbrake

[andrew_mx83]

So for various reasons i am moving away from the drum under disc handbrake setup in my mx83 track car. the handbrake will only be used for holding the car still while parked, no dorifto shit.... braking performance as such is not really an issue.

Best option so far seems to be a tailshaft mounted rotor and cable operated caliper.
Hydro wont be great for the caliper seals if kept under pressure for long periods, and the only calipers i can find with an integral cable handbrake are single piston.

Plan will be to mount the rotor on the diff flange, and a tiny caliper mounted to the subframe or diff housing. someone please correct me if i am wrong, but being mounted right in front of a 3.9:1 torque multiplier i only need about 1/4 the clamping force.

Looking at motorbike or possibly pocketbike rotors, with a gokart caliper....


Any thoughts/suggestions/things to watch out for?

[CrUZida]

Make sure its 100000% balanced, or you'll destroy your drivetrain.

[Duk]

Alfa Romeo did this in the late 60's and 70's before they went to their transaxle rear wheel drives. They used a drum brake, tho. Also, you better make sure your diff can't move around on its mounting bushes if you plan to mount the caliper on the subframe.

[thechuckster]

can't mount a second smaller caliper on the rear disks?

I take it that this is for rego purposes only? and has to be cable-driven or can the handbrake be a separate hydraulic system?

[andrew_mx83]

na not for rego, just to stop the car rolling away!! i figure if the hydraulic calipers are held under pressure for months at a time the seals will suffer.

first i looked at hyd calipers, with cable/lever operated handbrake but they seem to be only available in single piston. then i was gonna mount a small caliper on each disc as you say, but then figured the tailshaft would be easier, only 1 caliper needed, plus it would make the hubs simpler and lighter. also that way when i do a brake upgrade i dont have to remake the bracket.


im about to head off the the bike wreckers, will see what they have to offer.

[xa-mont]

if it is just to hold the car still... put it in gear... problem solvered.

[andrew_mx83]

not at the rate i blow gearboxes.....


damn bike wreckers are closed on mondays, ill mission it out there again tomorrow.

[xa-mont]

i'll have a rear brake rotor off my SV650 that might work for you tonight or tomorrow night (replacing it with fancy pants one)

[andrew_mx83]

sweet! do you know roughly what the OD is?
i have about 200mm max to the trans tunnel unless i massage it or turn the rotor down.

[xa-mont]

i believe it is ~220mm but if you run a small calliper on it i'm sure you would be fine with ripping some off the edge of the rotor.

You could probably get a smaller motorbike rotor, but you can have this for free and it will get it out of my shed

[andrew_mx83]

sweet as mate, sounds good. pm me where and what beer you drink

[xa-mont]

i'll let ya know when i have ripped it off.

[Hurricane]

alot of 4x4s have/had there handbrake setup on the back of the gearbox or transfer case. its common on 4x4 hiluxs to convert from the handbrake in the drum at the wheels to a cable and disc setup on the back of the transfer case between the tailshaft.

i think its some sort of bike caliper thats cable operated.

they do it so you dont have to run long cable to the wheels with lifted cars, big flex setup or brake upgrades with out a handbrake in them.

note that most/all transfercases have a flange (like the diff end) not a slip join into the back of the box. so mounting this type of setup is alot easyer.

if its on the tailshaft u want it, i would thikn it would be better to have it off the back of the gear box if it was possible (would have to be floating?)

ether way for a 2wd car i think its not a great idea.

why not run a 3rd caliper off one wheel disc, as a cable handbrake?
to me that seems a better way of doin it (apart from converting to a caliper with a cable handbrake on it)


dan..