Juggs running at full force and Cannonball is flying at him at full force. On impact who gets knocked out!
ya i read an x-men issue where juggernaut landed in new jersey after being beaten by onslaught in Canada. Wolverine treats canonball to a beer at a bar after beating wolverine and his motorcycle in a race. Juggernaut crashes the bar so he can quickly get a drink, cannonball is offended by juggernaut's prescence and being a litte drunk, he attacks juggernaut at full force and gets knocked out when crashing into his armour.
Cannonball came full force at Juggs back in an X-Force(drawn by Todd Mcfarlane-dope!)and he ricocheted off of Juggs with a concussion he felt through his blast field. Power levels have altered for both characters since then, but essentially I think the result would be similar.
The thing is Even though Cannonball was going really fast. And he was invulnerable both times. It knocks him out cold. Juggernaut doesn't even notice. You think Cannonball would have learned the first time. or maybe not, because of the massive head trauma.