Guide

The serial number on a Brompton is a ten-digit ID found on the frame; check the seat tube, bottom-bracket area, or the model’s plate/sticker.

On most Giant bikes, the serial number sits under the bottom bracket; some models use the seat tube, downtube, left dropout, or a sticker near the crank.

Chopper bicycles emerged in the early 1960s, with Schwinn’s 1963 Sting-Ray sparking the style and Raleigh’s 1969 Chopper cementing it.

The bike frame number is usually stamped under the bottom bracket; other spots include the head tube, seat tube, and rear dropout.

The bike registration number appears on the license plate and on your registration card, with repeats on frame stickers or head tube labels on models.

On most rail services, bikes go in marked bike racks, vertical hooks, or multi-purpose cars; folding bikes usually count as luggage when fully folded.

Measure a bike frame at the seat tube—from the bottom bracket center to the seat-tube top—using the brand’s stated method.

Bicycle history starts in 1817 with Karl Drais’s laufmaschine and crystallizes in 1885 with the safety bicycle that defines modern bikes.

Quad bikes were invented in 1982 when Suzuki released the first four-wheeled ATV, the QuadRunner LT125; three-wheel ATCs arrived earlier in 1970.

Replace mountain bike disc brake rotors when thickness hits the printed minimum, or if they’re cracked, warped, deeply grooved, or uneven.