Any reason why you don't want to just mount a Topeak rack?
Thanks waynesworld. Yes they wont fit. (or the ones that would, aren't strong enough)
The alternate rack I want to use the bag on mainly is an Old Man Mountain White Rock, which I bought as the only rack which would fit the canti bosses on a MTB. I would rather use Topeak than OMM but I need something sturdy.
I suppose I could weld some side plates on a Topeak rack to use the canti bosses. Hmm might be easier that way. BillP.