Gear Prudence: I live in the suburbs and mostly ride on trails. This time of year, it’s dark during my commutes, especially on the trails, so I’ve invested in a really powerful and expensive bike light, which I view as a necessity if I want to keep riding all winter. However, I also want to be cognizant of the other riders on the trail and don’t want to blind anyone. What are some best practices that I can use to be a polite but still remain able to see? —Bought Right Illumination Gear, Helpfully Travelling

Dear BRIGHT: It is right and proper for you to have spent the money on a sufficiently powerful bike light, especially if you’re riding through unlit woodsy trails in the gloom of winter. Too many area cyclists either skip the light entirely (which is reckless and discourteous) or use underpowered lights that cannot be relied upon to illuminate a forward path. And while you could have just trained an owl to fly ahead and report back the mysteries of the dark, it probably makes more sense to buy a good light and use it responsibly.

Always set a bright light on a steady beam. You are not a lighthouse—don’t flash. Secondly, point it down some rather than directly into the eyes of those riding toward you. It’s a bike ride, not an interrogation. And lastly, familiarize yourself with your light’s brightness adjustability. Most good lights have variable settings, so either get good at flicking to a lower setting when someone’s coming or save yourself the trouble and just screen the light with your hand for a second. The momentary reduction in visibility shouldn’t hamper you much. —GP

Gear Prudence: I got a flat tire last week and I fixed it—or at least I thought I did. When I went to check my bike again this morning after not riding it at all since I fixed it, the tire was flat again! I don’t get it. What gives? —Fixed, Left, Again Terrible

Dear FLAT: Since you didn’t ride your bike or park it atop of pile of jagged rocks, old sewing needles, and broken glass bottles, you probably didn’t pick up a new flat in the fallow period. And unless you live with a practical joker or a saboteur, you can rule out deliberate malevolent human intervention. GP thinks that it’s one of a few culprits: Either some sharpness is still stuck in the tire and has once again punctured your tube, or your tube has some defect (this sometimes happens, especially around the valve stem). Or if you patched the old tube, your patch didn’t hold. Fix it again, but take a few extra minutes to figure out the cause this time or it’ll keep happening. —GP

Gear Prudence is Brian McEntee, who tweets @sharrowsDC. Got a question about bicycling? Email