How do I figure out what rear axle to purchase for new wheel?
UPDATE: Halo like a number of other manufacturers make conversion kits  for converting between the different rear axle standards on a bike.

That is a 12mm thru axle rear wheel, which has become the new 'standard' for heavy duty mountain bike disciplines, like what the Halo Vortex has been designed for. I couldn't see any suitable adapters on the Halo website that allows you to convert the wheel, so I'd return the wheel and get something that fits.

Unfortunately the days where everything was 26" in diameter, 135mm wide and QR compatible are gone. The things that you need to check would be:


wheel diameter
axle type (QR or 12mm thru axle)
rear wheel spacing (135, 142, or 148)
you may also need to note down rim width depending on the width of tires that you're using