I’m guessing there won’t be any increase in stopping power – the braking force is distributed equally between both calipers – right?

If so then your adding weight and complexity purely to dissipate heat better

On a fat bike

Really!

I’m guessing there won’t be any increase in stopping power

The amount of friction material touching a disk is doubled so it must lead to some increase? And on a fat bike the tyre losing grip and the wheel locking under braking is significantly less of a problem than on a normal bike.

I’m guessing there won’t be any increase in stopping power – the braking force is distributed equally between both calipers – right?

If so then your adding weight and complexity purely to dissipate heat better

WTF ? Why in that case do all motorbikes above say 600cc use 2 discs ? Because it improves performance. Ok, so you need a master cylinder that works in accordance with it… but of course it improves performance.

WTF ? Why in that case do all motorbikes above say 600cc use 2 discs

Like I said – heat dissipation reducing fade

My Daytona has them

Like I said – heat dissipation reducing fade

Yes, partly… but mostly the stopping power.

Road bike motorbike brakes VERY rarely suffer from heat issues apart from on track.

Yes, partly… but mostly the stopping power.

Hows that then – You have doubled the braking surface area but halved the power to each caliper. Your hand is still applying the same force on the lever

Hows that then – You have doubled the braking surface area but halved the power to each caliper. Your hand is still applying the same force on the lever

No because your master cylinder has a larger internal bore, meaning it’s pushing more fluid at a given amount of lever travel/pressure.

That’s why aftermarket Brembo RCS masters come in say 16, 18 and 20 which is the bore, meaning it pushes more fluid.

You can fiddle with bore diameters on a single disc setup and achieve exactly the same result

ndthornton – Member

You can fiddle with bore diameters on a single disc setup and achieve exactly the same result

No, because you only still have 1 disk to give you braking surface. I accept you can make it better by having a larger ratio master cylinder, but usually at the expense of feel.

I think i’ll call it a day here as we’re not going to agree and it will just frustrate me 🙂

enjoy.

Someone mentioned bores?

Ok whatever

BTW – you need a smaller master cylinder bore (or a larger slave) to increase braking power. Not the other way around.

Breadcrumb has it

breadcrumb – Member
My OCD can’t cope with the discs being the opposite way round to each other!

Clearly they’re the opposing way around as one only works backwards, so it’s a fatty bike with a reverse gear and brakes to suit.

WTF ?

Brakes don’t have slave cylinders, clutches do though 🙂

Why in that case do single Supermoto caliper systems run a 13mm bore master cylinder and a Double disk Superbike system run a 20mm bore ?

Why in that case do single Supermoto caliper systems run a 13mm bore master cylinder and a Double disk Superbike system run a 20mm bore ?

Well I should think (and Im no brake expert) that its because on a double disc setup the brake fluid is being split between 2 calipers, halving the volume of fluid displaced in each slave piston and causing the pads to only retract by half the distance they would on a single disc setup. Therefor you need to increase the volume of fluid being displaced by the master to compensate and stop the pads rubbing.

That’s the thing you see – adding more calipers or more pistons to the same caliper or just increasing the size of a single piston (it all has the same effect) means you increase power at the expense of pad retraction. If you go so far with this you need a bigger master cylinder which cancels out your efforts. However you do gain better heat dissipation by doing this – which is the only reason to bother.

you don’t ever get something for nothing