I bought a secondhand Crossfire in May, it had only done 4.5 miles, the owner wanted a bike he could de-restrict and apparently that isn't possible on the Crossfire.
As you can imagine, the bike was in showroom condition.
All was fine for a while but then the dreaded cutting-out started, I had to keep restarting it with varying success.
Anyway, I took it to my local Halfords, they had a look at it and decided it needed a part they couldn't get, odd.
They simply gave me a brand new replacement, it was a bike they were about to put on display, they never even asked to see the receipt, (I have the original purchase Receipt)
The problem now is that the new bike is at least as bad as the old one, I've just come back from two weeks holiday in very hilly areas, sometimes it worked, often it didn't.
The problem varied, sometimes it just wouldn't turn on, even though it showed on the display, other times it felt like it was only working on one pedal, i.e. half a revolution and other times it seemed to surge. Sometimes It only worked when I pedalled really hard uphill, as soon as I relaxed a bit it stopped.
I've taken it back now and await their response, the problem I have is having bought it second hand I'm not sure how they'll view the warranty situation...