ST2 comes with a carbon fork and I wouldn't suggest a front rack on it.
You need steel fork with mounting points. You could instead use a trailer on an ST2.
The following comes directly from the ST-2 manual:
Front-wheel luggage carriers: "Front-wheel luggage carriers may not be installed or operated". (pp. 13-14)
I think this may be due to the carbon fork that is standard on the ST-2. Mounting a luggage carrier might produce some warranty problems down the road, let alone a possible accident while riding. Perhaps others have found a workaround?
Curious if the fork is changed to the comfort fork if it would work.
A side note I accidently bought a pair to Orleibs for the front that I won't use if anyone is interested. I still won't use the if they work w/my fork...