I really don't know how to explain it, but why do some hubs have nuts on the end. Like this one for example.
http://www.tartybikes.co.uk/1920_inch_wheels/onza_pro_wheelset/c61p11428.html
And others with allen key type like this one
http://www.tartybikes.co.uk/1920_inch_wheels/onza_blade_wheelset/c61p11427.html
Is one any better than the other, and can you swap them and such? I've had both type and it seems the type with the nut may slide about in the frame more? I don't want wheels that move. LOL
Just need some explanation on this stuff.