HillRider

The current RoadBikeRider newsletter addresses this exact problem and here are three suggested methods from their reader feedback:

Jan: Attach a long, straight stick (like a broom handle without the broom) to the handlebar. This will make any angular discrepancy between the handlebar and the frame easily apparent. That, and you can measure the distance from the floor to the ends of the stick if you are really uptight.


Mike: Take off the front wheel and wedge a 3-foot-long straight wooden dowel into the dropouts. Leave roughly equal lengths sticking out each side. This provides an excellent visual reference against which you can align the bar.


Dave: Lay a metal yardstick on its edge along the stem, sticking out over the front wheel. Carefully center it over the handlebar clamp. (These clamps often have a logo or faceplate bolt that is centered exactly, so this spot is easy to find.) Now the yardstick marks the exact centerline of the stem. The projecting end of the yardstick should exactly bisect the front tire if the stem is straight in line with the bike. Adjust until it does.