Lee,

I hope Im not telling my granny how to suck eggs here -

What is the gap between the brake pads and the rim?

If you have them so they are almost touching - perhaps a milimetre between the two, when you pull the brake lever you stop - FAST!

Spongey brakes are often the result of having too great a gap between rim and pad.

Its a doddle to adjust with nothing more than an allen key.

Chris