I no-tilled my beans with a 15" 900 cyclo this spring at over 9 mph.  The stand looks very good.  I may get flamed for suggesting speeds that high, but I've done it for years with a Kinze 6/11 prior to going to the IH planter this year.  If you are unsure, try a few rounds as a test plot where you can keep an eye on it and even check it with your yield monitor.  I would never dream of trying that with corn, however.