If you decide to use a standard wheel/tire as a spare, insure that you have lug nuts to fit. Many after market wheel lugs won't fit standard steel wheels.
Thanks Ethel - I have to agree - plus one of the ultralites seems to have suffered more than the others so would be a prime candidate for the spare and allow me to buy a new replacement. I can then fit the same tyres all round too. Just need to find a suitable place for the pump and source a jack!
Thanks. I actually bought a set of 5 alloys and tyres. The full set of 5 tyres were less than the price of 1 for my daily driver. Therefore no issue with bolts and sizes etc but thanks for the heads up.