Nice thread necro (although on a less active board)!
On topic, chances of evading a hit are determined by EVA, Ch-EVA, and VOID. Reduction of damage is determined by DEF. As they translate, it takes extremely high stats to be able to evade much of a given strike. That means one's chances of being hit are fairly high, so if there was a force dismount, you would be stuck if you fell under attack.
As it is, many of the Arkana I have encountered in Caergate and Viledon use their stun effects to halt any movement I might use, and kill me before it wears off. Being knocked off my bike would just compound the difficulties, since we cannot remount in combat.
Being stun-locked to death is just as annoying whether it's done from behind or while mounted. Your enemy already has plenty of ways to kill you, so why give them more?
Like streetlucifer said, either don't fall for the bait, or hunt in a pack. Stun-lock your enemy and take 'em down or return to the relative safety of the base (because NPC guards are too weak for the base divers).
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