Shimano XT Ring Bolts (annoying version)

On the left... a nice and easy, 'remove it with 2 hex keys', ring bolt.

On the right... an annoying as all *%^#, 'you need a special tool or 3 hands and a screwdriver, plus lots of time and patience' ring bolt. This particular one is from an XT crankset ('08 vintage I believe).

I don't think this is just a Shimano thing, but whoever thought this up just did not have the home mechanic in mind. Even with the special tool required (a Park CNW-2 chainring nut wrench) it's probably not smart to put your faith in said tool to grab fraction of a millimetre of soft alloy. Why bother when there are other designs around, that do the same job but can be undone with the tools just about everyone has at in their toolbox?

Luckily I have a spare set of the type on left lying around - the others certainly won't be going back on the crank they came off!