I believe Storm 2 and Tornado both use fixed axles and the wheels have pressed bearings inside and the wheels turn around the solid axle. This is mainly a good idea as you can run (to a certain extent) with a bent axle and keep going.

I believe razor have 2 parts to there rear axles. They have either side supported and the centre of the axle is cut in 2 so it can flex....Or something like that. I didn€™t quite understand when James cooper was explaining it all to me, best to get in contact with Ian Lewis on that.

If I understood your questions I think the 2 options above are good ways of mounting your wheels and axles.

Regards
Dave moulds
Team Turbine/PLF