Originally Posted by T-Mar

Having a fork alignment gauge greatly facilitates the process but it can be done without one, unless you want to be very precise. Before we start into a discusssion on aligning the blades we need to determine the root cause.

Non-centered wheels can also caused by incorrect wheel dish. If so, flipping the wheel will cause the problem to be off-center to the other side of the fork.

A higher dropout due to blade bend will also cause one dropout to be more forward, If so, the wheel, when viewed along the axis of the steering tube, will not sit at a right angle to the fork crown.

If the wheel is at a right angle to the crown, then the one dropout could be inserted further into the blade or at an angle or it could have a deeper slot. This can be determined by tracing the outline of one dropout and the lower for blade and then laying the other fork bade over the tracing to see if it matchs.

The final possibility is that the splay angle (lateral angle relative to the steering tube) is different between the blades. To check this you need to remove the fork, so we leave this step until last. Place a piece of 2 x 4 on a table and hold the steering tube in contact with the top of the block, with the blades overhanging the end of the block. Align the two blades vertically to the table surface using a carpenter's square. Then measure the distance from the table surface to the dropout. Now repeat for the other blade. If there is a difference in splay, the measurements will be different.