Quintessentium

hello

would 4 piston MTB disc brake callipers work with hydraulic road levers, particularly on sram brakes ?

I was not sure there’s no problem as 4 piston calipers would require larger volume on reservoir in levers.

many TIA !

fietsbob

[Homework] Learn: a bit of fluid dynamics,, kind of like economics_ supply & demand..
how much is displaced by the master cylinder piston, And what is the displacement volume of your 4 slave piston cylinders?

cxwrench

Or you could call/email SRAM and ask.

Quintessentium

I wish I can possibly reach to detail of design schematic of private company’s data …

maybe only way to detemine that is experimenting by myself probably?

Quintessentium

Manufacturers frequently seemed to respond conservatively and sometimes evade from effective attempts.

thanks for concern though

dsbrantjr

They might also need differently-sized master cylinders. The variables of master piston diameter and throw, lever mechanical advantage and slave piston diameter and number, and throw all interact, it is more complex than cable-operated brakes.

gsa103

True, but with the popularity of gravel and cross riding, there's likely to be a demand. For Shimano, the mtn levers are the same for one and two piston calipers, the same seems to be true for SRAM.

Iride01 

Why not just use the recommended levers of the same group and manufacture? Otherwise if you already have it, then give it a try and see first hand. Or keep some money in the budget to buy new levers if you want to experiment with your current levers.

Quintessentium

that’s actually what I’m a bit thinking about.

and having flat levers don’t seems too bad

Quintessentium

that’s how it seemed like that to me too

thanks for sharing it 😊

jp911

It's true that with cars you size the master cylinder to match the brake caliper piston diameters and it makes a big difference in effort required and ability to modulate. That said, it's also true that Shimano uses the same master cylinder in the lever between 2 and 4 piston XT brake calipers, but the total combined area of the pistons is not massively different between the 2 and 4 piston calipers. I can feel a subtle difference between the 2 systems freshly bled, where the 4-piston setup has a bit more travel and more sudden engagement, which is consistent with what happens when you undersize the master cylinder on a car.

Cyclist0108

This will work:

https://www.hopetech.com/products/br...front-caliper/

Quintessentium

oh wow

thank you for a way

Cyclist0108

I haven't tried them. But they are designed to be compatible, which in turn suggests that something like XT quad pistons might work as well (A=B and B=C implies A=C).

vespasianus

What I will say is that shimano 105 levers will work with cheap deore calipers. Those are two pot calipers. I would be that they work fine with the 4 pot calipers.