Well... reality and GW don't really have much of a connection.

The entire concept of a two wheeled vehicle being used in any meaningful way in a combat role is absolutely ridiculous. Besides the obvious terrain issues, and tire issues, ramming is completely out. Unless hit dead on, a minor hit to the sides of the front wheel, or a small jolt to the handlebars at all but the lowest speeds, will result in a crash. The fairly static profile makes them a much easier target, unless going at very high speeds, where even a slight change in balance, will result in a crash.

Even as a 'firefighter', aiming the bolters while maintaining control would be difficult at best. It'd be like firing a gun with your feet. Sure, it can be done, but any sense of accuracy or control is out the window. The close combat approach seems the most effective means of doing more damage than actually walking. And even then, you better hope your weapon cleaves through the enemy at about what you expect, else you'll over/undercompensate, and will result in a crash.

Bikes are fun. Bikes are economical. Bikes are not inherently stable except at high speeds on tarmac. Bikes at high speeds on tarmac don't take even minor external changes well. Bikes at slow speeds are bloody hinderingly awful. Minor incidents at slow speeds are hugely inconvenient. Minor incidents at high speeds are hugely dangerous.

That a Biker in 40K is in any way combat effective, is laughable. But what do I know, they look 'cool'. Dakka dakka Waaagh! Whatever.

Morgan Vening

Just a couple quick design concept notes:

Toughness and armor values are only guidelines. When necessary they can and should be discarded. Eldar Wraithlords have T in 40K, but they are AVs in Epic.

The assumptions of numbers of troops on a stand are relevant in terms of figuring out what the units should be vulnerable to. A normal infantry squad is assumed to be invulnerable to AT shots not because the weapons can't kill the squad but because killing 1-2 men still leaves the rest of the squad combat-effective.

The assumed number of troops per unit can also be used for determining other stats. For example, SM Bikes pack a lot more firepower than Tacticals, but there are only 2-4 (average 3) on a base instead of 3-7 (average 5) so they have the same FF value. The same thing applies to armor saves - +1 T on bikes offsets the lower numbers on an Epic unit, so they get the same armor.

pah, you just need more practice Morgan. I can fire my shotgun perfectly accurately from my bicycle using my feet AND at high speed, though I obviously can't pedal at the same time (I could get a hand crank though). I'm sure superhuman beings with 2 hearts and all that stuff can manage.