Students riding their bikes through debris-strewn Campus streets can save much time and money by knowing how to change a tube.

Cars get flat tires. Bikes, most often, get flat tubes.

The treaded outer part tends to last much longer than the delicate inner part hidden inside. Students riding their bikes through debris-strewn Campus streets can save much time and money by knowing how to change a tube.

Casey Karnes, owner of B1 Bicycles at 124 E. Long St., told us how to do it right.

1 Starting opposite the valve stem, scoop the smaller end of the both levers (generally $5 for a pair) beneath the same side of the tire. Rotate them downward, 180 degrees, to pop the bottom lip of the tire, known as the "bead," over the rim.

2 Slide the tire levers around the rim, bringing the bead completely over the rim. The tire's other side should remain between the edges of the rim. Reach beneath the tire and remove the old tube.

3 Inspect the underside of the tire and the rim to make sure no glass, cinder or thorn is lurking. Leftover debris will damage your new tube when it's inflated.

4 Make sure you're buying the right size tube (generally around $6) by reading info printed on the tire sidewall. Insert the valve stem through the hole in the rim and place the tube within the arc of the tire. If the new tube is crimped, folded or hard to insert, inflate it a bit to give it shape.

5 Starting at the valve stem, begin seating the exposed tire bead back into the rim. This should be done by hand, so the tube isn't damaged. When the tire is back within the ridge of the rim, check to ensure no part of the tube is sticking out.

6 Inflate the tire to the pressure listed on the sidewall of the tire.