HACK THE PLANET!!!
What suburb you staying in fam?No probs, next time my man. In the Castle at present. Do you know if there is a shop to hire a bike from?
I don't know for sure if any outright offer them for hire (as in a semi-decent road bike), but it'd worth ringing around.
Two Wheel Industries
Gateshead Cycles (actually at Warners Bay)
I think that's most places in Newy. One of them would be bound to offer something - I know Drift do a lot of demo days for MTBs, so I reckon try your luck there first. They're a a bunch of good eggs.
Just looked and there's a place I don't know much about in Newy called 'Metro Cycles', who apparently do bike hire. No idea if that'll include road bikes though.
Could also join a Facebook group called 'Newcastle Cycling Forum' and ask, they're a friendly bunch.