Trying to work out why these hubs have those huge closed-ended nuts on the axles… can anyone explain why they are necessary?

OK, so I understand that the axle has to be overly long to allow for the fact that some bikes have really thick dropouts, but on every bike I have seen them on they stick out a very long way.

Is there anything stopping you using normal open-ended nuts and sawing off the excess axle?
Would look a lot less goofy if you did…

nothing stopping you. they are there to stop you snagging your leg on the rough end of the poking out axle.

I put a set of these on, looks much better and you can colour match to your bike if you are a tart!

http://www.chainreactioncycles.com/Models.aspx?ModelID=34992

They look much nicer!
You can get them tight enough then?
I would have thought that might be difficult as they are aluminium.

Nope you can torque them pretty good, just make sure you use a socket or good spanner to avoid any rounding issues.

Alu wheel nuts were always shite on my mates bmx's, more chance of rounding, and the used to make horrible creaking noises.

you may not need to do them as tight on an mtb.

Steel is still far better