They should be marked on the swing arm - they'll say either BB7 Road or BB7 MTN.
With your Shimano levers, check the internals. Some Shimano levers have two actuation slots for the cable pull - one marked V which is further from the pivot, one marked C-R which is closer to the pivot. Usually there is a piece of red plastic which holds the cable end in the appropriate slot. If this is so and yours are set up on the V brake slots, pull the piece of plastic out (be careful !), move the cable end to the other ( Canti / Road) slot and re-insert the red plastic bit (Be careful !).
The plastic part is the bit labelled "4" in this exploded view PDF :
http://techdocs.shimano.com/media/te...9830612364.pdf which otherwise doesn't show much of the brake lever internals.
If you look carefully you'll see that compnent 4 is marked V C-R.