Most torque wrenches are woefully inacurate and are only used so you can blame something else when the threads strip. 22 Nm is there so the factory can't send them out loose, its the engineering equivalent of "some".
Unless you plan on rebuilding the motor next week and/or can afford a £200 wrench and calibration stuff to go with it, do it by feel. If it isn't tight enough they'll move when you swing on them, you don't need a gauge to tell you that.
Edit to add: if it worries you put a pen mark from the bars onto the riser and across the bolt head so you can see if they move.