If you care about weight enough to weigh your bike then I'm sure you would care if its accurate. The bathroom scale will get with in a few pounds. I used that method for a long time to weigh my backpacks for hiking. Depending on how you hold the backpack/bike you will get different readings. And this was done on a garmin smart scale. For me I'm only a weight weenie when I'm on a multi day hiking trip. One day if I lose 100 pounds I'm going to buy an awesome super light road bike.