I have some shimano LX disc breaks.

Now they have been blead and have new pads the roters are in good condition and ar not contaminated.

the back is perfect, but the front is awfull, it doesn’t seem to grip when traveling forwards however if i move the wheel backwards it bites and locks up.

The obvious non tech answer would be to turn the disc round but my knowlagable head says its got a rotation on the disc for a reason.

any Ideas of what could be causing it.