There seem to be 3 main places where some of those less fortunate seem to congregate.
Queen St around Greggs and the Nye Bevan statue, St John Church, and about 3/4 of the way down St Mary Street.
Don't let that put you off though as the electric bikes are far more of a danger to anyone of any age. There's also plenty of brilliant places to eat especially in the market and the old arcades.