MB used inboard fronts on the W196, Citroen used them on the DS and SM ( with underbody cooling ducts) and they were a key part of the Lotus 72 concept.
They seem to have dropped out of road use due to bigger rims allowing bigger discs, the general growth in weight helping (?) ride and the oil leak problems on rear ones.
In racing the advent of massive downforce raised sprung " weight" versus unsprung, so much any unsprung weight benefits were lost. Also inboard fronts made everybody nervous due to the high engineering quality required for safety.
As far as I can see there is no specific ban on inboard brakes , it just talks about "one brake per wheel" - a bit vague.
Why might inboard brakes have any benefit in todays F1?
Well, there is a lot of work going on for better aero flow through the wheels , no wheel mounted front brakes might give more aero opportunites, today even tiny aero gains seem valuable.. Not having to pump hot brake air out to the side of the car, as now, might cut drag
Having a nice, rotating vented disc requiring cooling air must be huge downforce opportunity whatever the regs say about ducting. The air has to come from somewhere and go somewhere so, whilst it might get banned after one season some clever rule reading could give the car " on board air pumps" within the rules.
Just a thought as F1 design is so stuck now - if it did work there is one last advantage - other teams couldn't copy it quicka s so much redesign of the tub etc. would be needed. Also with the modern levels of F1 enginnering the old safety worries needn't apply
Edited by mariner, 07 April 2013 - 17:08.