Quick Answer:  It is highly recommended that only a qualified mechanic mounts new handlebars, or controls onto your handlebars. When mounting the handlebar into the stem, or controls onto the handlebar, it is very important that torque is only applied until the point where slippage is eliminated, and that manufacturer’s maximum suggested torque ratings for the stem and controls are never exceeded. Always use a calibrated torque wrench, to ensure torque settings are accurate. Over tightening can lead to stress risers in the handlebar, which can cause premature failure and potentially accidents and/or injury.  Before mounting a new handlebar into your stem, remove the old handlebar, and clean your stem thoroughly, with careful attention to remove any contamination from the stem’s handlebar bore and faceplate.  Inspect your stem for any damage, including but not limited to deformation, discoloration, cracking, damaged bolt bore threads, etc. If any damage exists, do not continue to use your stem, and contact an authorized Spank service center for advice. Ensure the handlebar stem clamping zone is clean of any contaminants, and place the handlebar into the stem bar bore. Use the center marks on the handlebar to ensure it is correctly centered from left to right. Adjust the angle of the handlebar, so the upsweep and backsweep are a comfortable orientation for your personal preference. If you are uncertain of the required handlebar orientation, a good rule of thumb to start with, is to set the angle of the downward bend portion of the bar, at roughly the same angle as your fork legs (as shown in photo below). Lubricate and tighten the stem barclamp bolts just enough to allow rotation, then make small adjustments to the bar orientation until your own personal preference is reached, before locking down barclamp bolts.Once the handlebar is in your desired orientation, stem faceplate bolts should be tightened following the directions of the stem manufacturer carefully. If you are using a Spank Industries stem, faceplate bolts should be tightened in increments, in a top left bolt….bottom right bolt…top right bolt….bottom left bolt order, as shown below.If you are using a Spank Industries stem, as the bolts are tightened, ensure that the gap left between the stem body and stem faceplate, is equal from left to right, and top and bottom of the stem. The face plate of your Spank stem should NOT touch the stem body. If you are using a stem from another brand, please follow the directions provided by the stem manufacturer.Faceplate bolts used to secure the handlebar in the stem, should only be tightened until all slippage between handlebar and stem has been completely eliminated. Do not over tighten bolts. If you are using a Spank Industries stem, the maximum recommended torque is marked on your stem body or faceplate (see photo below showing Spike Race Stem and suggested max faceplate bolt torque of 9Nm). Do not exceed this model specific torque level, and always use a calibrated torque wrench to ensure accuracy.Once stem faceplate bolts are tightened, and before riding your bike in any kind of technical terrain, it is important to test the security of your handlebar for safety. Push and pull the bars forward and backward with considerable force to confirm the handlebar will not slip. After your first hard ride, and periodically during the term of use, the stem faceplate bolt torque should be checked with a calibrated torque wrench. If the torque value has reduced at all, tighten your bolts back to the original torque setting, and test to make sure your handlebars will not slip in the stem barclamp. If a significant torque reduction has been noticed, consult a qualified mechanic or authorized Spank service center for advice.  Before mounting your grips or controls, (example: shifters, brake levers, remotes), to your handlebar, clean the 22.2mm control zone of your handlebar carefully of any grease or contaminants. Controls should be mounted to the desired location on your handlebar, being careful to ensure you can reach your controls easily, while ample clearance has been achieved between your hands/grips and your controls, to avoid unwanted contact when riding. Control bolts should only be tightened until slippage is eliminated, but not so much that your controls cannot move in a crash or accident situation. It is important to check the suggested maximum torque provided by the control manufacturer, and never exceed this level. Some brake levers, shifters, and remotes have very low max torque ratings, sometimes as low as 2Nm. Over torque of control bolts can lead to stress risers in your handlebar, and premature failure and/or injury.  Once controls are mounted, grips can be tightened to the handlebar until slippage has been eliminated. If a max suggested torque is provided by the grip manufacturer, do not exceed this torque setting.