Inboard disk brakes?

[TEG]

Good idea or not? Less unsprung weight!






Used on some Jaguar, Citroen, Rover, Alfa Romeo, custom hotrods, race cars, etc.

[dsacks6]

I don't get it, don't the discs still turn like on normal car? If so how would there be less unsprung weight?

[WarpedOne]

In configuration on the last picture there realy is not much less unsprung weight but in the configuration on the first there is.
Brake disks are located near differential which is fixed to the chassies. They do not go up and down with wheels.

[TEG]

I don't get it, don't the discs still turn like on normal car? If so how would there be less unsprung weight?

Yes they turn so the rotating mass is the same, but they don't have to move with up and down wheel motion (as WarpedOne said) so it is easier for the wheels to bounce up and down quickly without transmitting as much motion to the rest of the vehicle.

Personally I think they seem like a good idea, but I don't understand why they haven't been more popular. Perhaps the intrusion into cabin space is too much of a downside.

[dsacks6]

Another downside is that it would be harder to check your brake pads.
Also in terms of looks, many love to see the brake calipers and disks ;D

[TEG]

But no brake dust on your nice shiny wheels!

Also it is probably nice to the tires to keep those red hot discs further away.

[Takumi]

Another downside is that it would be harder to check your brake pads.
Also in terms of looks, many love to see the brake calipers and disks ;D

Yes, cars that have been "upgraded" to 22" wheels, but retain stock brakes do look funny to me. Looks like something's missing.

[AGR]

Front inboard brakes 1972 Tyrrel F1, notice the driveshaft from the front wheel to the brake disc, and the ductwork to direct air to the disc.

[AGR]

1972 Tyrrell F1 rear inboard brakes

[AGR]

Modern F1 brakes with ceramic discs - notice the CF (carbon fibre) suspension arms, and CF air ducts to cool the brakes.