best bet is go for a tyre suited to the rim, better to go for the correct tyre than an oversized one or you will actually lose handling.
in the case of the standard rays its 245
no im ok mate standard will get me by in the mean time while i fill the piggy bank for the system i want.
incidentally i should have an exhaust sorted now fingers crossed
just opening one up now.
the details on the battery are 3.7V 200mAh so anything with a higher mAh rating than that would give more batt life but of course wouldnt fit in the case