Brake caliper mounting angle on steering knuckle
Brake caliper mounting angle on steering knuckle
(OP)
Hi,
I have looked quite a bit for an answer to this but with little success. I am in the process of designing a custom steering knuckle and would like to know whether there is an optimimum angle from horizontal or vertical at which brake calipers should be mounted. Most of the moutings I have seen are about 5 to 6 degrees from vertical. Is there a specific reason for this? Does mounting angle matter?
Thank you for helping me clarify this
I have looked quite a bit for an answer to this but with little success. I am in the process of designing a custom steering knuckle and would like to know whether there is an optimimum angle from horizontal or vertical at which brake calipers should be mounted. Most of the moutings I have seen are about 5 to 6 degrees from vertical. Is there a specific reason for this? Does mounting angle matter?
Thank you for helping me clarify this





RE: Brake caliper mounting angle on steering knuckle
RE: Brake caliper mounting angle on steering knuckle
If the vehicle is transverse engine front wheel drive, the engine/trans is in front of the axle which means the steering rack is behind the axle centerline (because it can't share space with the drivetrain) and the brake caliper will probably be in front, although it can and has been done otherwise.
Rear drive vehicles might not have the same constraint on where the steering rack is. My (rear drive) car has the steering rack ahead of the axle centerline and the brake calipers behind.
Theoretically, having front brake calipers behind the axle centerline puts less load on the wheel bearings because the upward force on the caliper while braking means there is a downward force on the wheel bearings which is the opposite direction that the weight of the vehicle is applying. But correctly sizing the wheel bearings means this isn't likely to be meaningful.
Don't forget that the caliper bleed screw has to be at the top.
RE: Brake caliper mounting angle on steering knuckle
RE: Brake caliper mounting angle on steering knuckle
RE: Brake caliper mounting angle on steering knuckle
I tried to write a proof of this last night, drawing little free body force arrows all over the place until my wife finally leaned over and said, “Why don’t you draw some little bows too, dear”.
The upshot is that I can’t prove it mathematically. But if the brake caliper were positioned to apply a lifting load on the wheel bearing, why wouldn’t the braking forces, if sufficient, also lift the car off the ground.
Maybe this is how Mary Poppins could fly. Her calipers were mounted to apply lift to her bearings and up she went, so long as she had her brakes on. Doesn’t sound right does it?
Anybody got a mathematical proof?
Bob
RE: Brake caliper mounting angle on steering knuckle
I looked at the forces and torques on the brake disc. I think you can either add or subtract from both the vertical and longitudinal loads on the bearings depending on where you locate the caliper.
RE: Brake caliper mounting angle on steering knuckle
Cheers
Greg Locock
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