Even the best helmet will fail if poorly fitted. Expect this to take some time. Measure your head and get the right size. Loose is no good, and too small will sit high or give you a headache.
- The helmet should fit as low on your head as possible without impinging on your ears. Adjust crown straps (hardhat-style suspension) or fit pads as needed. Removing the crown pad and replacing it with fleece is acceptable.
- The helmet should sit level on your head. As a general rule, the rim should be just barely visible when you look up.
- The Y of the side straps should meet just below your ear.
- The chin strap should be snug against the chin. When you open your mouth wide the helmet should pull down firmly.
- Push up and back on the brim. You should not be able to push the helmet above your forehead. If so, tighten the chinstrap and move the Y forward.
- Push upwards and across on the brim just in front of your ear. You should not be able to rock the helmet above your brow. Adjusting the brim tension and fit pads helps.
Some authorities state you should not be able to move the helmet more than an inch in any direction. We doubt you will attain that tight a fit and be able to stand it all day. Fit pads can help, but if the helmet is the wrong shape for your noggin, its going to pinch or slide no matter how much you tweak it.
The Yak whitewater (and sailing) helmet uses the familiar hard-hat style suspension system that tightens around the crown and vertically to adjust the height.
The Zhik sailing helmet uses padded inserts and a wheel to at the back to adjust fit.
The HB Olympus climbing helmet relies on a webbed suspension system to protect against falling rocks.
The Gath surf helmet is also used at the most extreme level of sailing.
A bump cap insert can slide inside your ball cap. It won’t protect you in the event of severe impact, but it will reduce the likelihood that a routine whack on the head will raise a welt or require stitches.