canti lever brakes were the first brakes offered on production mountain bikes , borrowed from cyclocross bikes , then the u-brakes made a ( thankfully ) short appearance as the " next best thing " .
they died as a result of ( a ) heavier than canti , ( b ) shitty mount location , ( c ) didn't work worth shit .
fortunately , linear pull brakes showed up soon thereafter , which represented a real improvement in braking performance .