View Full Version : dual calipers

09-11-2007, 12:33 PM
i bought a 15 inch slotted rotor, about 1/8 thick or so. also bought two matching dual piston calipers. i plan on mounting both calipers on the single disc. so it will be like a 4 piston setup. the calipers would be mounted together. both are the same type, came from the same bike, from dual front disc setup. but i have seen post saying this is not ok.. *why not? * also a question on banjo bolts. *i dont think i can afford custom length brake hoses, so is there a way to connect stock moto brake lines together with those banjo bolts of what? *im nieve about this.. * or can i use like auto steel brake line and connect the flexible moto lines to it somehow? * help, and explanations needed severly.. hahha *thanks alot guys.. *-Matt

09-11-2007, 06:12 PM
I would be concerned that the rotor was designed to handle the heat produced by one caliper and will warp or have other issues. 1/8" is pretty thin.

I am not advising it, but you probably could connect two lines at the banjos. There are banjo bolts that accept two banjos. Drakart Formula Crosses use them. You would have to have something to thread it into that blocks the flow.

09-11-2007, 07:04 PM
Dual calipers on a single rotor can work, but it can tend to overheat the rotor, as Livewire's stated. *Once the rotor's temp gets up there, it will glaze and you can loose braking ability. *A glazed rotor's wasted. *They can be brought back to life, but they don't last long at all.

Also, as Live said - beware of warping the rotor.

15"??? *Where do you plan on mounting this? *That's one big unit. *It tends to take away ground clearance. *Not saying it won't work, though. *A large rotor like that, slotted, as you mentioned, should be able to handle the heat - or so I would tend to think.

Two calipers on one master cylinder (m/c) - just like the front of a street bike. *If you can find a setup off of the front of a motocross bike - fairly long lines - maybe a couple of them will work. *That would only require one dual banjo bolt. *You can also run a single line from the m/c to one caliper and then use the dual banjo bolt on that and have the second line go from the input of the first caliper to the second. *Just make sure that the banjo bolt and the bleeder screws are at the top of the caliper or you'll catch air and won't be able to bleed them.

You can pick up things like banjo bolts and the ends from places like Summit Racing, Pegasus Racing and other racing warehouses. *Also look at Russell's and Earl's products. *They would be where I'd start.

a * lot... alot * a lot

09-11-2007, 07:16 PM
On a small mini i would think one caliper would be sufficient.How heavy a machine are you building?A rotor that large will take up a lot of space.I don't know the design your working on , but is it possible to go with 2 smaller rotors with a caliper on each?

09-11-2007, 07:19 PM
Ditto what has been said about heat and warpage etc.

You could run 3/16" PTFE brake lines (the same stuff that's inside the stainless braided lines) which is only cents per foot. It's rated at around 3,000 PSI (the average brake systems seldom sees much more than 1,000 PSI). It won't swell like cheap rubber flexible lines can (over a certain length) and it's the easiest thing to plumb around tight spaces.

Use conventional/braided stainless flexible lines to the front wheels though, as a rock could damage the unprotected PTFE lines.

Ordinary compression fittings are used with PTFE lines, but just make sure you get the correct olives for it; they're different to the olives used with the same fittings for metal hard lines (they have an internal tube to prevent the olive colapsing the line when the nuts are tightened).

You can also use 3/16" Nylon line. It's normally rated at around 1,200 PSI and will still do the job OK for what you need it for.

09-11-2007, 07:31 PM
I Have nylon brake lines on my car, they work well and easy, with a stainless to the wheels, I use one rotor on the jackshaft wich intern dbls the braking power thru gearing....and a dynalite single 2 piston caliper. It has no problem locking the tires and stalling the engine.... [smilie=biggrin.gif] *Thats with a 9" diam *3/8 thick mild steel rotor...Not once has it been to hot either...

09-12-2007, 12:07 AM
Correct me if i'm wrong but *with a massave rotor like a 15" you wouldn't be using it very hard to get the same braking as a smaller rotor like maybe a 9or10" after all, the buggy still weighs the same and it still takes the same entergy to stop, i know with a larger rotor there is more leverage plus more surface area to dissipate the heat. The larger rotor will not produce as much heat as a smaller rotor doing the same job!!!!! Probably wouldn't need another caliper. The brakes can only work as well as the tires/traction allow anyhow. The bike that came off of was way over braked if a street bike and if a race bike, i doubt you would work your brakes that hard or that often unless you race too and if so then you would have big brakes on the front also .

09-12-2007, 02:30 AM
that rotor is from some type of bike.. i can always take back the stuff i got and exchange it no hassle.. *this was my reasoning for getting what i got.. remember i am nieve about this stuff yet. *i picked out the big rotor, thinking like on cars, bigger rotors are better, for stopping power.. also i figured with a bigger rotor i would need a simulated 4 piston caliper.. hence the dual dueces...lol * but it doesnt matter..i can get a two smaller rotors and just put a caliper on each, i have plenty of room. *also, if im using a master cylinder from the dront of a street bike. mid 90's. *can i mount it sideways, upside down and all that? or do i have to mount it like on the bike? * thanks for all the help, and advice. *so final verdict, what should i go with?

09-12-2007, 06:38 PM
also, if im using a master cylinder from the dront of a street bike. mid 90's. *can i mount it sideways, upside down and all that? or do i have to mount it like on the bike? * thanks for all the help, and advice. *so final verdict, what should i go with?

The big problem i see there is trying to fill it [smilie=biggrin.gif]

09-12-2007, 07:23 PM
You have to keep the res above the piston - so you need to mount it more or less with the fill plate flat. Otherwise you'll end up getting air in the system.

09-13-2007, 02:23 AM
oh duh.. i cant believe that went over my head.. * *hahaha... * thanks

09-13-2007, 06:44 AM
oh duh.. i cant believe that went over my head.. * *hahaha... * thanks [smilie=alright.gif]

09-15-2007, 01:17 AM
ok so i took that rotor back. i dont think it was from a bike.. it was too large and thin. * *i ended up finding a rotor just like my gs1000 rotors.. *similar to the one that is in my pictures (from my suzuki 1000). * the new rotor is 10.5 inches, by 3/8 inch thick. has bunches of oblong holes drilled into it.. looks cool.. *now i just need to get a hub made for my axle.