Bottom bracket powermeter - square/octalink/huh?

[Ant.]

Warning - semi long and boring read, but I'd love answers.

I'll be the first to admit, I'm not a full book on anything cycling, except for the pedalling part, and the changing of tyres (which takes me a good six minutes on a quick-nothing-goes-wrong day).

My roadie at the moment isn't very great (masi nuova strada), however I've prioritised that i'll chuck a powermeter in it before upgrading the frame around it.
Ergomo pro power meter is what I'll go for - it's what is on my TT bike, so I can keep the same computer and just buy a sensor, plus I really really dig the layout, the altitude part and the % gradient, etc. Never owned a different power meter and do not plan too.

Essay over. Sorry guys.

These are the options I can get:
ergomo® pro ISO square BSA 102 mm
ergomo® pro ISO sguare BSA 111 mm
ergomo® pro ISO square ITA 102 mm
ergomo® pro ISO square ITA 111 mm
ergomo® pro Octalink BSA 109,5 mm
ergomo® pro Octalink BSA 118,5 mm
ergomo® pro Octalink ITA 109,5 mm
ergomo® pro Octalink ITA 118,5 mm
ergomo® pro ISIS BSA 108 mm
ergomo® pro ISIS BSA 113 mm
ergomo® pro ISIS BSA 118 mm
ergomo® pro ISIS ITA 108 mm
ergomo® pro ISIS ITA 113 mm
ergomo® pro ISIS ITA 118 mm


Now, here's where I have a stony cold look on my face. I don't know what I don't know. The dura ace stuff on my TT bike is pretty funky, so my eventual roadie will have them, err, answer the questions that I want to ask

edit. What one do I buy, and why? <-- that seems to be the question. Any further bottom bracket education however, will be thoroughly appreciated.

[ozlegacy]

ISO square is the old square tapered stuff
octalink is the older style BB from about 3-4 years ago/
ISIS i belive is the new hollow crank stuff

Then you have either italian or British standard threading, then the BB width two sizes

I might be wrong on the cranks, but basically what bottom bracket are you runnign? once we know that it's probably a easier choice

[Nobody]

http://en.wikipedia.org/wiki/Bottom_bracket

[twizzle]

Interesting stuff.... After reading the Wikipedia, I'd be going for the square taper.