Guide

Replace a bike helmet after any crash or clear damage, and plan a refresh around the five-year mark based on use and fit.

Yes—replace bike brake pads when friction material is near 1 mm, when you hear wear indicators, or when braking power fades.

Change a bike chain at 0.5–0.75% wear (earlier for 11–12-speed) or when shifting slips under load.

The first rider-propelled two-wheeler appeared in 1817; the modern “safety” bicycle took shape in 1885.

The bicycle’s story spans 1817–1818 for the first two-wheeler, 1866 for pedals, and 1885 for the modern safety design.

Before a long bike ride, eat 1–4 hours ahead: carb-rich, low-fat, low-fiber foods plus fluids and sodium for steadier energy.

For Trek bike size, use your height and inseam with Trek charts; if between sizes, go smaller for control or larger for reach.

Most bikes use 1/2-inch pitch chains; pick 1/8-inch for single-speed and narrower widths for multi-speed drivetrains.

Adult bike size matches your height and inseam; check frame size and standover for a safe, efficient fit.

A modern bike chain uses 1/2-inch pitch; pick 3/32″ for derailleurs or 1/8″ for single-speed, and match the rear speed for outer width.