Space marine bikes as troops?

[striogi]

I've been browsing and searching your forums and cannot locate the answer, so maybe I'm just missing the option in AB -

Trying to build a white scars list and my 7-strong bike squads are not converting to troops, instead of fast attack. I have Kor'sarro Khan on his bike with a command squad.

is there a switch I missed flipping?
I would be greatly surprised if this was something that has not yet been addressed.

thanks.

---*edit*

D'oh - Found it. >.<