Reading A Motorcycle Jacket Size Table Before You Buy A Size Run

A garment factory measures a jacket flat on a table, not on a body. That is why the rows say half chest rather than chest: the jacket is laid flat and measured across, so the figure is half the circumference.

The two Creease rider jacket patterns publish full tables in centimetres. One runs M to XXL, the other M to XXXL. On the larger pattern, half chest runs 59, 61, 63, 65 and 67 cm across M to XXXL with a tolerance of plus or minus 1.5 cm.

• Half chest. Double it for the garment circumference. Compare against the wearer's chest plus room for a protector and a layer underneath.
• Half bottom. The hem circumference. A jacket where the hem is much narrower than the chest will ride up on a sport bike.
• Centre front and centre back. The body length. Centre back is longer than centre front on a riding jacket by design, so the lower back stays covered in a forward riding position.
• Sleeve length. Measured on a flat sleeve, so it will read short compared with a shirt sleeve measured from the neck.
• Half shoulder width. The row that most often decides whether a jacket fits a broad rider who is otherwise a standard size.

A tolerance of plus or minus 1.5 cm on half chest is plus or minus 3 cm on the finished circumference. Across a run, that means two garments in the same labelled size can differ by a noticeable amount. That is normal in apparel manufacturing.

Two things follow. First, do not publish your own size chart to a precision the tolerance cannot support. Second, if a tighter tolerance matters for your brand, make it an explicit line in the purchase specification rather than assuming it.

A riding jacket is worn over a body, a base layer, and often a back protector. The published back insert patterns are 33.5 x 23 cm and 41 x 29 cm. A jacket that fits perfectly with an empty back pocket will be tight with a 41 x 29 cm protector in it. Size the run with the protector fitted, not without.

If you are supplying the jacket and the inserts together, check the pocket size against the insert pattern before the first production run rather than after it.

The same labelled size sells at different volumes in different markets. Take the factory table, convert it into the measurement language your customers use, and set your own labelling on top of the factory grade. Send us your graded table and we will tell you what can be matched against the existing patterns.