Thanks for the reply. Unfortunately, I don't have a triple shifter or triple crankset -- front is only a double, hence the desire to consider whether a different crankset could be used.

I am certainly willing to put on a triple crankset and loose the outer chainring in favour of a bashguard, but if I can't go lower than a 30T inner chainring, its not much use (I already have a 32T on my double).

Is it possible to use a mtb crankset, double or triple, and still shift with my Tiagra 2x9 front derailleur/STI shifters?